project: moe fls reference€¦ · project 246313 file nelson two storey block (concrete stairs) -...

Project: MOE – FLS

Reference Designs for

Standard Classroom Upgrade

Nelson Two Storey Block

(Concrete Stairs)

Structural Calculations:

Christchurch

Reference: 246313

Prepared for: Ministry of

Education

Revision: 0

09/08/2016

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Project 246313 File Nelson Two Storey Block (Concrete Stairs) - FLS Upgrade Calculations Christchurch - Rev 0.docx 09/08/2016 Revision 1

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Report Title MOE – FLS Reference Designs for Standard Classroom Upgrade – Nelson Two Storey Block (Concrete Stair) - Structural Calculations: Christchurch

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Nelson Two Storey Block (Concrete Stairs) - FLS Upgrade Calculations Christchurch - Rev 01.docx

Project Number 246313

File Path P:\246313\03 Project Delivery\Design\Nelson Block\Nelson Two Storey Block (Concrete Stairs) - FLS Upgrade Calculations Christchurch - Rev 01.docx

Client Ministry of Education Client Contact

Rev Date Revision Details/Status Prepared

by Author Verifier Approver

0 09/08/2016 JBM JBM LP JF

Current Revision 0

Approval

Author Signature Approver Signature

Name Jagnesh Makwana Name John Finnegan

Title Structural Engineer Title Technical Director

Jagnesh.Makwana

Image

FLS Reference Designs for Standard

Classroom Upgrade – Nelson Two Storey

Block (Concrete Stairs)

Structural Calculations: Christchurch

SUMMARY 3

1. BUILDING OVERVIEW 4

1.1 Original Structure 4

1.2 Flexible Learning Space (FLS) Upgrade – Option 1 7

1.3 Flexible Learning Space (FLS) Upgrade – Option 2 8

2. LATERAL LOADING DEMANDS 9

2.1 Seismic Loading 9

2.2 Imposed Actions 15

2.3 Horizontal Design Action Coefficients 17

2.4 Wind Loading 25

2.5 Design Loading For Lateral Bracing 31

3. LIFT SHAFT DESIGN 32

4. LINTEL DESIGN 45

5. FLEXIBLE LEARNING SPACE (FLS) OPTION 1 62

5.1 Overview/Bracing Scheme 62

5.2 Option 1 Annex Structure 63

5.3 Longitudinal Bracing Capacity – First Floor 66

5.4 Longitudinal Bracing Capacity – Ground Floor 70

5.5 Longitudinal Capacity Summary 84

5.6 Transverse Bracing Capacity – First Floor 85

5.7 Transverse Bracing Capacity – Ground Floor 89

5.8 Transverse Capacity Summary 99

5.9 Roof Diaphragm capacity 100

5.10 Floor Diaphragm Capacities 102

5.11 Summary of Capacities for Option 1 107

5.12 Critical Seismic Capacities 114

6. LOAD TRANSFER BETWEEN CENTRAL BLOCK & END BLOCK 115

7. INCREASING LAT. BRACING CAP. TO 67% OF NZS 1170.5 REQUIREMENTS FOR OPTION 1 116

7.1 Loading Demands 116

FLS Reference Designs for Standard

Classroom Upgrade – Nelson Two Storey

Block (Concrete Stairs)

7.2 First Floor Strengthening 119

7.3 Ground Floor Strengthening 121

8. FLEXIBLE LEARNING SPACE (FLS) OPTION 2 133

8.1 Overview/Bracing Scheme 133

8.2 Option 2 Annex Structure 134

9. SUMMARY OF EXISTING CAPACITIES FOR OPTION 2 137

10. INCREASING LAT. BRACING CAP. TO 67% OF NZS 1170.5 REQUIREMENTS FOR OPTION 2 138

10.1 Loading Demands 138

11. OPTION 2 SEISMIC STRENGTHENING 141

11.1 End Block First Floor Strengthening 141

11.2 End Block Ground Floor Strengthening 143

11.1 Central Block Strengthening 158

12. FOUNDATIONS 187

13. WALL HOLD-DOWNS 188

13.1 Proprietary Bracing Elements 188

Client: Ministry of Education Date: 09/08/2016

Project/Job:

FLS Reference Designs for Standard Classroom Upgrade Job No:

246313

Subject: Nelson Two Storey Block (Concrete Stairs) - Christchurch Sheet No: 3 By: JBM

Summary

The Ministry of Education (MOE) wishes to provide schools with standard options to modify their classrooms to allow for

a Flexible Learning Space (FLS).

This document provides detailed calculations for the standard options to create a FLS for a Nelson Two Storey Block

(Concrete Stairs). These details are intended to be generic and have been developed with the following site

characteristics:

Importance Level 3

Site Subsoil Class D

Location Christchurch

An allowable soil bearing pressure of 250kPa has been used. This is the same allowable soil bearing pressure used for

the MoE Generic Seismic Strengthening package for the Nelson Block 2 Storey Block for the Modern Learning

Environment (MLE) layout proposed in 2014. This allowable soil bearing pressure is to be confirmed based on site

specific geotechnical investigation for each building. It is assumed that each building is located on a flat site.

Two destructive tests carried out at the Mairehau High School and Upper Hutt College have confirmed that the End

Blocks and the Central Block of the building are adequately tied together to allow for load transfer between the blocks.

This has been considered for final %NBS scores.

This document provides structural calculations for two FLS options set out by the MOE. These are Option 1 and Option

2. The main variances between the two options lie in the footprint the smaller breakout areas have relative to the general

flexible learning areas. For these strengthening schemes, the lateral bracing elements are to have a minimum capacity

of 67%NBS.


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1. Building Overview

1.1 Original Structure

Nelson Blocks are the single most common secondary school block type. They were first designed in 1960

and were constructed throughout the 1960’s. Their use was widespread throughout the entire country.

Nelson Blocks have an ‘H’ shaped plan layout and are of lightweight timber framed construction, with a

lightweight roof. Since these classroom blocks were designed prior to the introduction of the 1965 Seismic

Code, it appears the lateral resisting elements were specifically designed for wind loading only.

A selection of two-storey Nelson Block structures contain stairs constructed out of reinforced concrete with

adjacent reinforced concrete shear walls. This calculation package will focus on the seismic strengthening

of these types of Nelson Block structures.

A front view of a typical two-storey Nelson Block is shown in the figure below:

- Elevation of Typical Two Storey Nelson Block with Concrete Staircase

Lateral seismic loads in both directions are resisted by timber framed shear walls evenly distributed

throughout the structure, as well as reinforced concrete shear walls tied into the concrete stairs.

Compared to the regular Nelson Two Storey with Timber Staircases the End Blocks lack bracing elements

in the transverse walls, with windows extending along the entire length. The end walls do not have any

sarking. The walls of the staircase on the first floor are timber framed and the walls on the ground floor are

reinforced concrete.

The Centre Block is shorter by one Window bay and the roof of the Centre Block does not connect to the

End Blocks. The layout of the interior walls also differs slightly from the regular Nelson Two Storey Block.


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Typical floor plans of the first floor and the ground floor for a two storey Nelson Block with concrete stairs

are shown in the figures below:

- Typical Ground Floor Plan of a 2 Storey Nelson Block Structure with Concrete Stairs

Two destructive tests carried out at the Mairehau High School and Upper Hutt College have confirmed that the End Block

and the Central Block are adequately tied together to allow for load transfer between the blocks. This has been

considered for final %NBS scores.

Annex Room – Excluded from the calculations as

it has a separate roof diaphragm and therefore

structurally independent from main Nelson Block

structure. To be assessed on case by case basis


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- Typical First Floor Plan of a 2 Storey Nelson Block Structure with Concrete Stairs


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1.2 Flexible Learning Space (FLS) Upgrade – Option 1

Option 1 for the FLS upgrade consists of opening up the classroom areas to create a flexible learning space. Alterations

are made with the existing layout, creating small and large breakout spaces.

To allow for the FLS upgrade, as well as to strengthen the lateral bracing capacity of the structure to meet a minimum

capacity of 67%NBS, new Gib bracing walls and steel portal frames are to be installed throughout the structure.

The figure below shows a plan layout with the preliminary structural scheme for the new FLS layout.

FLS Layout and Structural Scheme Option 1


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Subject: Nelson Two Storey Block (Concrete Stairs) - Wellington Sheet No: 8 By: JBM

1.3 Flexible Learning Space (FLS) Upgrade – Option 2

Option 2 for the FLS upgrade varies from Option 1 through having fewer small breakout areas and has two medium

breakout areas on the ground floor. The structural system for this option will require the installation of steel portal frames

in certain locations where Gib bracing walls were considered for Option 1.

The figure below shows a plan layout with the preliminary structural scheme for the new FLS layout.

FLS Layout and Structural Scheme Option 2


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2. Lateral Loading Demands

2.1 Seismic Loading

- General Parameters

The lateral forces that must be resisted by the elements in a building are a function of the seismic weight and the

horizontal acceleration as estimated by the horizontal design action coefficient.

Earthquake actions are calculated as per the equivalent static method, which applies the force due to the weight of the

roof and upper half of the walls at roof level and the force due to the total weight of the building at foundation level.

From NZS1170.0, section 4.2.1, the ultimate limit state load combination that relates to earthquake actions is as follows:

𝐸𝑑,𝑑𝑠𝑡 = 𝐺 + 𝐸𝑢 + 𝛹𝑐𝑄

𝐺 = 𝑃𝑒𝑟𝑚𝑎𝑛𝑒𝑛𝑡 𝐴𝑐𝑡𝑖𝑜𝑛𝑠

𝐸𝑢 = 𝐸𝑎𝑟𝑡ℎ𝑞𝑢𝑎𝑘𝑒 𝐴𝑐𝑡𝑖𝑜𝑛𝑠

𝑄 = 𝐼𝑚𝑝𝑜𝑠𝑒𝑑 𝐴𝑐𝑡𝑖𝑜𝑛𝑠

𝛹𝑐 = 𝐸𝑎𝑟𝑡ℎ𝑞𝑢𝑎𝑘𝑒 𝐶𝑜𝑚𝑏𝑖𝑛𝑎𝑡𝑖𝑜𝑛 𝐹𝑎𝑐𝑡𝑜𝑟

Seismic Weight

The general dimensions of the structure are illustrated below:


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Permanent Actions:

- Roof

The roof is constructed of the following:

Sarking

Corrugated Iron

Building Paper

Timber Frames

Plasterboard Ceiling

Hence, assume that roof has a unit-weight of 0.35kN/m2

Roof Unit Weight WUr = 0.35 kPa

Area

Central Block Roof Area Acbr = 22.07m 8.03m = 177.222 m2

End Block Roof Area Aebr = 22.07m 8.79m = 193.995 m2

Weight

Central Block Roof Weight Wcbr = WUr Acbr = 62.028 kN

End Block Roof Weight Webr = WUrAebr = 67.898 kN

Total Roof Weight Wr = Wcbr + 2 Webr = 197.824 kN


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First Floor

The first floor is constructed of the following: Diagonal Flooring

Timber Joists

Plasterboard Ceiling

Carpet

Hence, assume the first floor has a unit-weight of 0.50 kN/m2 + Concrete (Stairway)

Unit Weights

5’’ Concrete Slab WU5 = 3.048 kPa

Timber Floor WUf = 0.5 kPa

Floor Area

Central Block Area Acbf = 25.73m 7.57m = 194.776 m2

End Block Timber Floor Area Aebf = 2 9.14m 6.35m = 116.078 m2

End Block Concrete Floor Area Aebcf = 3.05m2.26m+3.05m3.56m+1.5m2.08m = 20.871m2

Floor Weight

Central Block Wcbf = WUf Acbf = 97.388 kN

End Block Webf = WUf Aebf + WU5 Aebcf = 121.654 kN

Total Weight Wf = Wcbf + 2Webf = 340.696 kN


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Walls – Upper Floor:

The upper floor walls are constructed of the following:

Asbestos Cement

Timber Sarking (some panels)

Building Paper

Framing

Plasterboard

8” Concrete (Staircase)

Wall height on the First floor is 3.05m

Unit weights

Walls (No Sarking) WUns = 0.3 kPa

Walls (Sarking) WUs = 0.45 kPa

Glazing WUgl = 0.2 kPa

Column Type A & B WUcol = 6 kN/m3

.

Type A is 14” x 5” with the actual timber being 4 individual elements at 2” x 5” with 2” spacing.

Type B is 14” x 8” with the actual timber being 4 individual elements at 2” x 8” with 2” spacing.

There are 8 Type A columns in each End Block and 10 Type B Columns in the Central Block

Total Column A Weight Wcola = WUcol 4 2in 5in 3m 8 = 3.716 kN

Total Column B Weight Wcolb = WUcol 4 2in 8in 3m 10 = 7.432 kN

Wall Area

Central Block

Sarked Walls Acbsw = 2 22.07m 1.2m = 52.968m2

Internal Walls Acbiw = 4 7.57m 3m + 3.53m 3m = 101.430m2

Glazing Acbgl = 2 22.07m 1.65m + 4 1.83m 2.75m = 92.961 m2

End Block Walls

End Walls Aebew = 2 6.35m 3m = 38.100 m2

Sarked Walls Aebsw = 29.14m1.2m + 7.62m1.2m+7.1m1.2m = 39.600 m2

Internal Walls Aebiw = 2 7.21m 3m + 7.51m 3m = 65.790 m2

Glazing Aebgl = (29.14m+(7.62m+7.1m))1.65m+3.05m3m = 63.600m2


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Wall Weight

Central Block Wcbw = AcbswWUs+AcbiwWUns+AcbglWUgl+Wcolb = 80.289kN

End Block Webw = AebswWUs+ (Aebew +Aebiw)WUns+AebglWUgl+Wcola = 65.423kN

Total Wall Weight Wtotw = Wcbw + 2Webw = 211.135 kN

Walls – Lower Floor:

The floor height of the lower level is equal to 3.4m. Take the upper half of the lower floor walls (1.7m).

Spandrel Panels These are in the lower half of the walls therefore load generated from these panels gets

transferred directly to the foundations.

Unit Weights

8’’ Concrete Slab WU8 = 4.877 kPa

Timber Floor WUf = 0.5 kPa

Walls (No Sarking) WUns = 0.3 kPa

Walls (Sarking) WUs = 0.45 kPa

Glazing WUgl = 0.2 kPa

Column Type A & B WUcol = 6 kN/m3

Total Column A Weight Wcola = WUcol 4 2in 5in 1.7m 8 = 2.106 kN

Total Column B Weight Wcolb = WUcol 4 2in 8in 1.7m 10 = 4.212 kN

Wall Area

Central Block

Internal Walls Acbiwgf = 4 7.57m 1.7m + 3.53m 1.7m = 57.477m2

Glazing Acbglgf = 2 22.07m 1.1m + 4 1.83m 1.7m= 60.998 m2

End Block Walls

End Walls Aebewgf = 2 6.35m 1.7m = 21.590 m2

8 ‘’Concrete Walls Aebcwgf = 2 7.21m 1.7m = 24.514 m2

Internal Walls Aebiwgf = 7.57m 1.7m = 12.869 m2

Glazing Aebglgf = (29.14m+7.62m+7.1m)1.1m+3.05m1.7m= 41.485m2

Wall Weight

Central Block Wcbwgf = AcbiwgfWUns + Acbglgf WUgl + Wcolb= 33.654kN

End Block Webwgf = WU8 Aebcwgf + (Aebewgf+Aebiwgf) WUns WUgl Aebglgf + Wcola

= 140.295 kN

Total Wall Weight Wtotwgf = Wcbwgf + 2 Webwgf = 314.245 kN


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Totals

The total self-weights are as follows:

- Roof

Central Block Wcbr = 62.028 kN

End Block Webr = 67.898 kN

Total Wr = 197.824 kN

- First Floor

Central Block Wcbf = 97.388 kN

End Block Webf = 121.654 kN

Total Wf = 340.696 kN

- First Floor Walls

Central Block Wcbw = 80.289 kN

End Block Webw = 65.423 kN

Total Wtotw = 211.135 kN

- Ground Floor Walls

Central Block Wcbwgf = 33.654 kN

End Block Webwgf = 140.295 kN

Total Wtotwgf = 314.245 kN

- Total Loads

Central Block Wcb = Wcbr + Wcbf + Wcbw + Wcbwgf = 273.359 kN

End Block Web = Webr + Webf + Webw + Webwgf = 395.271 kN

Total Building Weight W = Wcb + 2Web = 1063.900 kN


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2.2 Imposed Actions

Live Load Q is equal to 4.0 kN/m2 for stairs, landings and corridors and is equal to 3.0 kN/m2 for all other areas. The

stair, landing and corridor areas for the first floor are highlighted below:

Q3 = 3 kPa

Q4 = 4 kPa

An Area Reduction factor can be applied for the live load this factor is equal to the following:

Central Block acb = 0.3+3(1m2)/((Acbf)) = 0.515

Central Block aeb = 0.3+3(1m2)/((Aebf)) = 0.578

It is to be noted that this reduction factor cannot be applied to stairs, landings and corridors (as per clause 3.4.2 NZS

1170.1).

- Area with 4 kPa

Central Block A4kpacb = 1.83m 7.57m = 13.853 m2

End Block A4kpaeb = Aebcf = 20.871 m2

- Area with 3 kPa

Central Block A3kpacb = Acbf - A4kpacb = 180.923 m2

End Block A3kpaeb = Aebf = 116.078 m2


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- Live Load

3 kPa

Central Block Qcb3 = A3kpacb acb Q3 = 279.503 kN

End Block Qeb3 = A3kpaeb aeb Q3 = 201.436 kN

4 kPa

Central Block Qcb4 = A4kpacb Q4 = 55.412 kN

End Block Qeb4 = A4kpaeb Q4 = 83.484 kN

Total Seismic Weight

The total seismic weight of the structure is given by the following formula:

Wt = G + ψEQ

E 0.3 (Earthquake Live load reduction factor)

Central Block Wtotcb = Wcb + E (Qcb3 + Qcb4) = 373.834 kN

End Block Wtoteb = Web + E (Qeb3 + Qeb4) = 480.746 kN

Total Wtotal = Wtotcb + 2Wtoteb = 1335.327 kN

Total Seismic Weight per level

- Roof Level

Central Block Wrlc = Wcbr + 0.5Wcbw = 102.172 kN

End Block Wrle = Webr + 0.5Webw = 100.610 kN

- First Floor

Central Block Wflc = 0.5Wcbw+Wcbf+Wcbwgf+E(Qcb3 + Qcb4) = 271.662 kN

. End Block Wfle = 0.5Webw+Webf+Webwgf+E (Qeb3+Qeb4) = 380.137 kN


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2.3 Horizontal Design Action Coefficients

Seismic Coefficient Variables:

Importance Level: Importance Level 3 – Important Structure

Design Working Life: 50 Years

Fundamental Period: Tn = 0.4 seconds

Site Subsoil Class (Section 3.1.3): D – Deep or Soft Soil

Site Location (Table 3.3): Site Location 102 - Christchurch

NZS1170.5 – Section 3.1: Elastic Site Spectra for Horizontal Loading:

C(T) = Ch(T) Z R N(T,D)

Where:

Ch(T) = spectral shape factor from Clause 3.1.2

Z = hazard factor from Clause 3.1.4

R = return period factor from Clause 3.1.5

N(T,D) = near fault factor from Clause 3.1.6

This gives the following seismic coefficients for various ductilities:

Lower Sp factor for timber from 0.7 to 0.5. This is in accordance with MoE guidelines:

Seismic Coefficient (ductility of 3) Cd3.0 = 0.3822 0.5/0.7 = 0.273

Seismic Coefficient (ductility of 2.5) Cd2.5 = 0.4410 0.5/0.7 = 0.315

Seismic Coefficient (ductility of 2.0) Cd2.0 = 0.5212

Seismic Coefficient (nom. ductile 1.25) Cd1.25 = 0.9470

Seismic Coefficient (elastic 1.0) Cd1.0 = 1.170

The aforementioned ductilities are to be used for the following cases:

- Ductility 3.0 - Used for timber framed sarking, plywood and plasterboard bracing walls in the

seismic strengthening design.

- Ductility 2.5 - Used for timber framed sarking, plywood and plasterboard bracing walls in the

original seismic assessment. This is as recommended in Ministry of Education guidelines for

buildings constructed prior to 1970.

- Ductility 1.25 (Nominally Ductile) – Used for the roof cross bracing system and reinforced

concrete walls under shear actions


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Base Shear

The total base shear of the structure is given by the following equation:

Vb = Cd(T1)Wt

Cd3.0 = 0.273

Cd2.5 = 0.315

Cd1.25= 0.9470

Cd1.0 = 1.17

The Sp factor for timber has been lowered to 0.5 from 0.7 in accordance with MoE guidelines.

Force Distribution up Structure

Nelson Blocks are two-storey, light weight timber structures. Distribute the loads up the structure using the

equivalent static method as per NZS1170.5

Fi = Ft+0.92Vb*(WiHi/ΣWiHi)

Where: Fi is the force at a given level

Ft is equal to 0.08Vb at roof level and 0 at all other levels

W1 is equal to the weight of the first floor plus the upper half of

the walls in the lower level plus the lower half of the walls in the

upper level

W2 is equal to the weight of the roof plus the upper half of the

walls in the upper level.

When distributing the forces up the structure, calculate the demands for the end blocks and the central

section separately.

The structure is typically timber framed walls. Under Ministry of Education guidelines, a ductility of 2.5 is to

be used for the assessment of timber framed structures that have been constructed prior to 1970. A ductility

of 3.0 however can be used for the seismic strengthening design of timber framed structures. Therefore use

ductility 2.5 demands (timber) and 1.25 (concrete) for the assessment and ductility 3.0 (1.25 for concrete)

demands for the seismic strengthening.


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- Central Block

Base Shear (Cd(T) = 1.0) Vb = Wrlc + Wflc = 373.834 kN

Ft = 0.08 Vb = 29.907 kN

Height roof level hr = 6.65m

Height first floor hf = 3.4m

Roof Level Wihi Wrhr = Wrlc hr = 679.446 kNm

First Floor Wihi Wfhf = Wflc hf = 923.649 kNm

Wihi SUMwh = Wrhr + Wfhf = 1603.095 kNm

Loads to Roof Fr = Ft +0.92Vb (Wrhr / SUMwh) = 175.675 kN

Loads to First Floor Ff = 0.92Vb (Wfhf / SUMwh) = 198.159 kN

= 3.0

Loads to Roof = 3.0 Fc3.0r = Cd3.0 Fr = 47.959 kN

Loads to First Floor = 3.0 Fc3.0f = Cd3.0 Ff = 54.097 kN

= 2.5



= 1.25



= 1.0




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- End Block

Base Shear (Cd(T) = 1.0) Vb = Wrle + Wfle = 480.746 kN

Ft = 0.08 Vb = 38.460 kN

Height roof level hr = 6.65m

Height first floor hf = 3.4m

Roof Level Wihi Wrhr = Wrle hr = 669.056 kNm

First Floor Wihi Wfhf = Wfle hf = 1292.464 kNm

Wihi SUMwh = Wrhr + Wfhf = 1961.520 kNm

Loads to Roof Fr = Ft +0.92Vb (Wrhr / SUMwh) = 189.320 kN

Loads to First Floor Ff = 0.92Vb (Wfhf / SUMwh) = 291.427 kN

= 3.0

Loads to Roof = 3.0 Fe3.0r = Cd3.0 Fr = 51.684 kN

Loads to First Floor = 3.0 Fe3.0f = Cd3.0 Ff = 79.560 kN

= 2.5



= 1.25



= 1.0




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2.4 Wind Loading

Determine lateral wind loading demands (in accordance with NZS 1170.2) on the structure to confirm which lateral

loading form governs.

Basic Wind Pressure Calculation

Wind Region = A7

Importance Level = 3

Terrain Category = 3

Shielding Multiplier (Ms) = 1.00

Topographical Multiplier(Mt) = 1.00

Vdes SLS = 30.7m/s

Vdes ULS = 38.2m/s

PBasic SLS = 0.565kPa

PBasic ULS = 0.876kPa

These wind parameters have been calculated for a terrain category 3 site with no topographical and shielding factors.

These may need to be altered when a design is carried out for a specific Nelson Two Storey Block with different site

parameters.

The spreadsheet calculations to determine the basic wind pressures are shown on the next page.


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Ratio of SLS to ULS demands = (30.72) / (38.22) = 0.65 Multiple ULS demands by 0.65 to obtained SLS demands.


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Design Wind Pressure Calculation

As per Cl 2.4.1 of NZS1170.2, the design wind pressure is calculated by the following equation:

Pdesign = Pbasic x Cfig x Cdyn

PBasic ULS = 0.876kPa

Cdyn = 1.0 (Low rise single storey structure with natural frequency above 1Hz)

Determine Cfig for different loading faces and directions:

Cp,i = NA (Internal pressures cancel each other out)

Windward Face:

Cp,e (W) = 0.7 (Table 5.2(A) - h<25m, wind speed doesn’t vary with height)

Leeward Face:

Longitudinal Loading

h = 6.65m

d = 38m

b = 23m (breadth of end blocks)

d/b = 1.65

Cp,e (L)Long = -0.3 (Table 5.2(B) Roof Pitch is 15 degrees)

Transverse Loading

h = 6.65m

d = 23m

b = 38m

d/b = 0.6

Cp,e (L)Trans = -0.3 (Table 5.2(B) Roof Pitch is 15 degrees)

See page 9 for the Nelson Two Storey Block dimensions.


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Kc,e = 0.8 (Table 5.5 - 3 Effective Surfaces)

Ka Long = 0.8 (Table 5.4 – >100m2 Tributary Area)

Ka Trans = 0.8 (Table 5.4 – >100m2 Tributary Area)

Kp = 1.0

Kl = 1.0 (Bracing elements not directly supporting the cladding)

Cfig,e = Cp,e x Ka x Kc,e x Kl x Kp

Cfig,e W = 0.7 x 0.8 x 0.8 x 1.0 x 1.0

= 0.45 (All directions)

Cfig,e L (Long) = -0.3 x 0.8 x 0.8 x 1.0 x1.0

= -0.19

Cfig,e L (Trans) = -0.3 x 0.8 x 0.8 x 1.0 x1.0

= -0.19

Hence, the net Cfig factors are as follows:

Cfig net (Long ) = 0.45+0.19 (Windward and leeward)

= 0.64

Cfig net (Trans) = 0.45+0.19 (Windward and leeward)

= 0.64

The ULS design pressures in both directions are therefore equal to the following:

PdesULS(Long) = 0.64 x 0.876kPa

= 0.56 kPa

PdesULS(Trans) = 0.64 x 0.876kPa

= 0.56 kPa (0.39kPa Windward, 0.17kPa Leeward)


Project/Job:


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Roof Pressures:

Gable roof structure for upwind and downwind slopes has a pitch of 15


h = 6.65m

d = 38m

h/d = 0.175

Cpe = -0.5 (Table 5.3B)

Transverse Loading

h = 6.65m

d = 23m

h/d = 0.289

Cpe = -0.53 (linear interpolation Table 5.3B)

Under cross wind loading

Cpe = 0.2 (Table 5.3A for horizontal distances >3h from windward edge)

Critical wind uplift pressure:

Puplift (ULS) = 0.876kPa x 0.8 x 0.8 x -0.53

= -0.3kPa

Critical wind downward pressure:

Pdownward (ULS) = 0.876kPa x 0.8 x 0.8 x 0.2

= 0.1kPa


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Wind Shear Forces

F_WindLong, roof level = 0.56kPa (23m 3.25m 0.5)

F_WindLong, roof level = 20.9kN

F_WindLong, first floor = 0.56kPa (23m 3.3m)

F_WindLong, first floor = 42.5kN

F_WindTotal, Long = 63.4kN

F_WindTrans, roof level = 0.56kPa (38m 3.25m 0.5)

F_WindTrans, roof level = 34.6kN

F_WindTrans, first floor = 0.56kPa (38m 3.3m)

F_WindTrans, first floor = 70.2kN

F_WindTotal, Trans = 104.8kN


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2.5 Design Loading For Lateral Bracing

Compare earthquake and wind loadings to determine the critical force to design the lateral bracing.

Majority of the lateral bracing elements in this system will be from new Gib bracing walls. For these elements use a

ductility of 3.0 and an Sp factor of 0.5.


Central Block

= 3.0


Loads to First Floor = 3.0; Fc3.0f = Cd3.0 Ff = 54.097 kN

End Block

= 3.0


Loads to First Floor = 3.0; Fe3.0f = Cd3.0 Ff = 79.560 kN

Total Loads to Roof = 3.0 FEQ, roof = 151.3 kN

Total Loads to First Floor = 3.0 FEQ, First floor = 213.2 kN

F_WindLong, roof level = 20.9kN

F_WindLong, first floor = 42.5kN

Hence, seismic loading governs the lateral bracing design in this direction. The bracing will need to carry a minimum of

67% of the seismic loading in this direction to meet minimum MOE requirements.

Transverse Loading

Total Loads to Roof = 3.0 FEQ, roof = 151.3 kN

Total Loads to First Floor = 3.0 FEQ, First floor = 213.2 kN

F_WindTrans, roof level = 34.6kN

F_WindTrans, first floor = 70.2kN

Hence, seismic loading governs the lateral bracing design in this direction. The bracing will need to carry a minimum of

67% of the seismic loading in this direction to meet minimum MoE requirements.


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3. Lift Shaft Design

The following design of the lift shaft and lift pit has been based on a lift which was constructed for a previous project.

Calculations are for a generic two-storey steel lift shaft with a Schindler Lift. This lift shaft design is common for both

Option 1 and Option 2.

s

Following loads are provided by Schindler Lifts NZ Ltd:

Weight of lifting beam Wlifting_beam = 19.62 kN

Reaction loads P1 = 47.5 kN

P2 = 25 kN

P3 = 13.8 kN

P4 =17.9 kN

P5 = 24 kN

Seismic Rail forces Car = 4.04 kN

C_Wt = 2.81 kN

Scaling factors for loads SFload_variability = 1.5

Dynamic factor from Table 3.4 NZS1170.1 SFdynamic_factor = 2.0

Included on the following pages are extracts from the Schindler Lifts shop drawings.


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Factored load P = Wlifting_beam SFload_variabilitySFdynamic_factor = 58.860 kN

Length of beam Llifting_beam = 2.03 m

Maximum moment for simply supported beam Mmax = (PL)/4 = 29.871 kNm

Minimum section modulus required Zmin = Mmax / (300MPa 0.9) = 110635.000 mm3

Use 150UB18 (Zex = 135x103 mm3)

End reactions for beam R = P/2 = 29.50 kN

Support Beams for Lifting Beam:

Support end reactions from lifting beam results in a 29.5kN point load at mid-span

Length of support beam Lsupport_beam = 1.75m

Maximum moment Mmax_LB = (RLsupport_beam)/4 = 12.876 kNm

Minimum section modulus required Zmin = Mmax_LB / (300MPa0.9) = 47687.500 mm3

Use 125x75x4.0 RHS (Zex = 60.3x103 mm3)

End reactions R support_beam = R/2 = 14.715 kN


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Corner Columns

Reaction load from support beams result in axial compression load of 14.7kN on corner columns. Assume columns are

pinned at both ends.

Capacity of column determined as per Chapter 6 of NZS 3404:1997

Axial section capacity Ns = kf An fy

Axial member capacity Nc = cNs

Where c is calculated by section 6.3.3 of NZS3404. From calculations below use section larger than 75x2.0 SHS


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Steel Trimmer Design:

Factored loads Car = SFload_variability SFdynamic_factor 4.04 kN = 12.120 kN

C_Wt = SFload_variability SFdynamic_factor 2.81 kN = 8.430 kN

Rail_load= C_Wt/2 = 4.215 kN


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Shear force and bending moment diagrams for steel trimmer:

Steel Trimmer Size:

Maximum moment Mmax = 6.85 kNm

Minimum section modulus required Zmin = Mmax / (300MPa0.9) = 25370.370 mm3

Require 75x4.0SHS or larger

Use 125x75x4.0RHS (Zy = 37.4x103 mm3)

RHS is loaded about its minor axis so Zy must be larger than Zmin.


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Corner Column Design for Trimmer Loads:


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Factored loads Car = 12.120 kN

C_Wt = 8.430 kN

Total lateral load to bracing Fbracing = Car/2 + C_Wt = 14.490 kN

Braces are to be considered to act in tension only

Tension load into cross brace Fbrace = (Fbracing /1750) 2811 = 23.275 kN

Designing cross brace:

Safety factor for steel brace in tension = 0.9

Minimum cross sectional area of steel required Amin = Fbrace/(300MPa) = 86.204 mm2

For 5mm thick plate need a width greater than 17mm. Therefore use 50 x 5 mm plate

Load in Column Fcolumn = (Fbrace /2811) 2200 = 18.216 kN

Unrestrained length is equal to 5m. Assume pin connections at top and bottom of columnRequire 75x2.0SHS or larger

(from calculations on page 34)

Use 75x4.0SHS to match wall thickness of trimmers


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Shaft is braced at 1st floor level. If car is at ground level during an earthquake the columns will have to resist the induced

bending. The shaft is not tied back at the roof level hence cross bracing is required.


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Length of column Lcolumn = 5.1 m

Maximum moment for column Mmax = ((Fbracing/2) Lcolumn)/4 = 9.237 kNm

Minimum section modulus required Zmin = Mmax / (350MPa0.9) = 29325.000 mm3

Use 75x5.0SHS (Zex = 33,600mm3)

Deflection Check

Serviceability under earthquake loading:

Allowable deflection allowable = span/300

Requires 89x5.0SHS

Resulting deflection from loading = 11.68 mm = span/342


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Project/Job:


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Floor Slab Design

Dynamic factor from Table 3.4 NZS1170.1 SFdynamic_factor = 2.0

Right hand side of slab highlighted in figure above has critical loads

Loads at centre of span Fmidspan = P1 + 2 P4 + 2 P5 = 131.300 kN

Factored load at centre of span Ffactored = SFdynamic_factor Fmidspan = 262.600 kN

Loads at end span P3 = 13.8 kN

Factored load end span P3_factored = SFdynamic_factor P3 = 27.600 kN

Linear springs will be used to model the soil reactions

Space Gass printouts on the following page show the modelling procedure


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Maximum moment in slab Mmax = 60.21 kNm

Assume 250mm deep reinforced concrete slab with 16mm diameter bars, fy = 300MPa, f’c = 30MPa and 50mm cover.

Depth of slab dslab= 250 mm

Diameter of steel reinforcement dsteel= 16 mm

Yield strength of steel fy = 300MPa

Compressive strength of concrete fc = 30MPa

Safety factor for concrete in flexure = 0.85

Internal lever arm jd = 0.95 (dslab – 50mm) = 190.000 mm

Minimum area of steel required Asmin = Mmax/( fy jd) = 1242.724 mm2

Number of 16mm bars required No. = Asmin /(( dsteel2)/4) = 6.181

For 1000mm width spacing required spacing = 1000mm/No. =161.791 mm

Use 150mm spacing

Checking bearing pressure of slab:

Maximum reaction is 20.31kN over 0.125m length with 1m width,

Bearing pressure Pressure = 20.31kN/(0.125m 1m) = 162.480 kPa

Resulting bearing pressure is close to 150kPa allowable limit however approach here is conservative so bearing pressure

is deemed to be okay.


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4. Lintel Design

Structural schemes for Option 1 and Option 2 on pages 7 and 8 show new lintels. These are required for both the ground

and first floor as existing timber walls supporting gravity loads are to be removed. Lintel 1 is not required for Option 2 as

floor loads are to be supported by steel portal frames instead.

Lintel 1

Existing timber walls along gridlines 3 and 6 from the bracing schemes on pages 7 and 8 are to be removed. These

existing walls allowed flooring joists to span between laminated timber beams and timber walls at each end of the central

block. Design lintel to be a PFC beam simply supported on new SHS posts to support these floor loads.

Total span of PFC lintel is 7.3m. Tributary width is 2.9m.


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300PFC lintel is found to adequate. Design of SHS post is on the next page.


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SHS Post

300PFC is simply supported between new SHS posts. Vertical shear reactions for 300PFC become axial loads for SHS

posts. Must design posts to carry 55kN under ULS 1.2G+1.5Q load case (obtained from the previous page).

89x5SHS post is found to be sufficient. MemDes outputs are shown below:

Description : SHS Post

Section : 089x089x5.0 SHS Grade 350

d = 89 mm b = 89 mm tf = 5.0 mm tw = 5.0 mm

Area = 1590 mm2 fyf = 350 MPa fyw = 350 MPa fu = 430 MPa

**** MAJOR axis bending ****

Flange : le Ratio = 18.7 / 40 = 0.47

Web : le Ratio = 18.7 / 130 = 0.14

Section is COMPACT, Zex = 49.10 E3 mm3

Flange : le Ratio = 18.7 / 130 = 0.14

Web : le Ratio = 18.7 / 40 = 0.47

Section is COMPACT, Zey = 49.10 E3 mm3

Axial Calculations

Design Action Nd = 55.0 kN [Comp], LeAxx = 3.65 m, LeAxy = 3.65 m

Sect. Compression Capacity Ns = kf An fycomb

= 556.5 kN

Major axis buckling : ac = 0.4162

acx < 1.0 => Ncx = acx Ns = 231.6

Minor axis buckling : ac = 0.4162

acy < 1.0 => Ncy = acy Ns = 231.6

Minimum Capac. Ncmin = 231.6

Axial buckling capac. Ratio = Nd / f Ncmin

= 0.264,

======================== SUMMARY =====================

**** U.L.S. Capacity Check Passed, Load Cap. Ratio = 0.26 ---- OK ----

============================================================


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Foundation Pad

89x5SHS posts are to be founded on new individual pad foundations 600mm deep.

Assume ground bearing capacity of 250 kPa.

Try 500x500mm pad:

Bearing pressure = 55 kN/0.5x0.5m = 220kPa,

Reinforcement design is shown below:


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Lintel 2

Design Lintel 2 to be timber and simply supported between laminated timber column ‘C’ and existing timber framing.

Total span is 3m. Lintel 2 supports a point load reaction from Beam A as well as floor loads. Beam A is an existing 6”x3”

timber beam supporting floor joists. Firstly determine loading on Beam A and then design Lintel 2 based on point load

reaction and floor loads.

Beam A

Tributary width = 1.25m

Span = 2.14m

Loads:

150x50 floor joists at 400crs = 0.081kPa

Ceiling 3/8” plasterboard = 0.067kPa

SDL (services etc.) = 0.2 kPa

Live load = 3kPa

Critical ULS load case occurs under 1.2G+1.5Q

w (1.2G+1.5Q) = 1.25m x [1.2 (0.081+0.067+0.2) + 1.5(3)] = 6.15kN/m

Critical SLS load case occurs under G+0.4Q

w (G+0.4Q) = 1.25m x [(0.081+0.067+0.2) + 0.4(3)] = 1.9kN/m


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Beam A is simply supported. Point load reactions onto Lintel 2 are:

R (1.2G+1.5Q) = (6.15kN/m x 2.14m)/2 = 6.58kN

R (G+0.4Q) = (1.9kN/m x 2.14m)/2 = 2.03kN

Lintel 2 is also subject to point load reactions from Lintel 4 (1.25m span) above. These are determined in section 4.1.4:

R (1.2G+1.5Q) = 0.8kN

R (G+0.4Q) = 0.5kN

Floor loads arise between concrete stair and Beam A. Loads to be supported are the same as for lintel 1. G = 0.35kPa,

Q = 3 kPa. Tributary width is 1m shown below:


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Lintel 2 Design

SpaceGass outputs are shown below:

BMD under ULS 1.2G+1.5Q:

SLS Displacements:


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Using 250x100 SG8,

Moment capacity Mnx = 8.8kNm > M*max = 7.44kNm, Okay

Maximum SLS displacement = k2 x 3.42 = 6.84mm. Deemed to be okay, deflection is less than 1mm over limit.


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Lintel 2 is to be supported on column ‘C’ and new 90x90 SG8 (double stud) using Bowmac bracket and joist hanger:


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Lintel 3

Lintel 3 supports the same loads are lintels 1 and 2. Total span is 2m with 1m tributary width:

From spreadsheet calculations on the next page 200x100 SG8 is found to be okay. Support lintel using Bowmac brackets

connecting to new 90x90 SG8 double studs.


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Project/Job:


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Lintel 4

Design Lintel 4 to be made up of three simply supported spans on timber posts. Maximum span length is 3.7m, other

two spans are 2.5m and 1.25m. Lintel supports 1m width of tributary roof load. Lintel 4 will be supported by new 90x90

SG8 double studs into existing timber framing at ends. Internal span will be supported on 90x90 SG8 posts.

Roof loads:

200x50 ceiling joists at 450crs = 0.097kPa

Acoustic ceiling tiles = 0.19kPa

Purlins/paper/braces = 0.09kPa

Galvanised steel profile 0.6mm = 0.08kPa

Live load = 0.25kPa

SDL, services = 0.2kPa

Wind uplift = -0.3kPa

Wind downward = 0.1kPa


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Total gravity load G = 0.097 + 0.19 + 0.09 + 0.08 + 0.2

= 0.66kPa

Q = 0.25kPa

d/b = 1.65

Load combinations:

w1.2G+1.5Q = 1m x [(1.2x0.66) + (1.5x0.25)]

= 1.17kN/m

w0.9G+Wup = 1m x [(0.9x0.66) + (-0.3)]

= 0.29kN/m

w1.2G+Wdown = 1m x [(1.2x0.66) + (0.1)]

= 0.89kN/m

wG+0.7Q = 1m x [(0.66) + (0.7x0.25)]

= 0.84kN/m

wG+0.4Q = 1m x [(0.66) + (0.4x0.25)]

= 0.76kN/m

Spreadsheet calculations are on the following pages. Use 200x100 SG8


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Lintel 4 is okay to be supported by 90x90 SG8 double studs. Vertical reactions found on the previous pages are far less

than the axial capacity of 18.5kN for 90x90 SG8 post.


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5. Flexible Learning Space (FLS) Option 1

The Ministry of Education wishes to have the option of converting existing Nelson Block – 2 Storey buildings into Flexible

Learning Spaces (FLS). Existing structural capacities are to be determined first with calculations for strengthening

options in subsequent sections.

5.1 Overview/Bracing Scheme

The preliminary bracing scheme is shown in the figure below.

Justify the preliminary structural scheme is adequate to resist lateral loading demands. The critical areas to check are

as follows:

Transverse Direction:

o New steel portal frames on the ground floor

o New Gib bracing walls on both ground and first floor

Longitudinal Direction:

o New Gib bracing walls on bracing lines A+ and A


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5.2 Option 1 Annex Structure

The Annex structure highlighted on page 5 has a separate roof diaphragm and is structurally independent from the main

Nelson Block structure. The preliminary bracing scheme for Option 1 on page 62 shows new Gib walls for lateral bracing

of the modified Annex structure. GIB EzyBrace spreadsheets are to be used to determine if the bracing scheme is

sufficient. This method is suitable as the Annex structure is independent from the main building, constructed out of

lightweight timber and single storey.

Wall bracing along gridline A+ will resist lateral loads in the longitudinal direction from both the Annex structure and the

central block.


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Total surplus capacity Capsurplus = 2493-2211= 282 BU

This surplus capacity is used to resist lateral loading in the longitudinal direction for the central block by load transfer along gridline A+. Total surplus capacity of 282 BU equates to 14.1kN.


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Gib BL1-H is adequate.


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5.3 Longitudinal Bracing Capacity – First Floor

Gridlines A, B, C and D are timber framed walls with plasterboard lining. The exterior walls are lined with GS1 while the

interior walls are lined with GS2.

The capacities according to MoE Guidelines are (multiply capacity with height factor 2.4m/h):

height first floor

height factor for first floor

GS1 Capacity

GS2 Capacity

Wall Capacities per Gridline

GL A - End Block

GL B - End Block

GL C - End Block

GL D - End Block

hff 3.05m

fff 2.4m

hff

0.787

GS1 3kN

m

GS2 4.25kN

m

la 2 6.35 m 12.7m

Ra la 2 fff GS1 14.99kN

leb 2 7.21 m

Reb

leb

2fff GS2 24.112kN

lc 2 7.21 m 14.42m

Rc

lc

2fff GS2 24.112kN

ld 2 6.35 m 12.7m

Rd

ld

2fff GS1 14.99kN


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Gridline A+ & C+

Wall Capacity

The walls extend up to the window level and can be assumed to have a bracing capacity equal to Gib GS1.

Since the height of the walls is below 2.4m the height factor will be 1.0.

Check Column capacity to determine which governs.

Column Capacity

The columns are 14” Deep x 8” Wide (355.6mm x 203.2mm) consisting of 4 individual timber members (each 2” x 8”)

spliced together (as shown below).

Flexural Capacity (in accordance with NZS 3603:1993):

Wall Capacity

5 Elements Connected

Conservative

Assume Rimu

Rac 22.07m GS1 66.21kN

Mnco 4 k1 k4 k5 k8 fb Z

0.8

k1 1.0 EQLoading( )

k4 1.26

k5 1.0

Lay 1650mm

b 203.2mm

d 50.8mm

k8 1.0

fb 19.8MPa

Zb d

2

68.74 10

4 mm

3

Mnco 4 k1 k4 k5 k8 fb Z 6.977 kN m


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Axial Capacity (in accordance with NZS 3603:1993):

Need to determine the axial load subject to each column under the G + ψcQ + Eu load case.

Assume Rimu

Total Weight Central Block

Floor Area Central Block

Tributary Area of Columns

Consider Biaxial Effects

Reduced Flexural Capacity

NcCol 4 k1 k8 fc Ac fc

k1 1.0 EQLoading( )

fc 20.1MPa

Lax 3400mm

Lay 1.65m

S3 Lay d 32.48

S2 Lax b 16.732

k8 0.32

Ac d b 1.032 104

mm2

NcCol 4 k1 k8 fc Ac 212.463kN

Wtotcb 373.834kN

Acbf 194.776m2

ta 4.41m7.57m

2 16.692m

2

Nx

ta

Acbf

Wtotcb 32.037kN

UNcol

Nx

NcCol

0.151

Bef 1.0 UNcol 0.849

Mnco2 Bef Mnco 5.925m kN

Mn Mnco2 Lay 3.591kN


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Shear Capacity (in accordance with NZS 3603:1993):

Drift Limit (in accordance with NZS 3603:1993 and NZS 1170.5):

Maximum allowable drift limit is equal to 2.5% of the column height.

Critical Column Capacity:

Scale ductility to 1.0

Treat column as fixed cantilever

Column Capacity Gridline A+ and C+

Governing Capacity for Gridline A+ and C+

VnCol 4 k1 k4 k5 fs As fs

fs 3.8MPa

As2

3b d 6.882 10

3 mm

2

VnCol 4 k1 k4 k5 fs As 105.439kN

max 2.5% Lay 41.25 mm

P Lc3

3 E I( ) P

E 9500MPa

Ib d

3

122.22 10

6 mm

4

Lc Lay 1.65 m

P4 max3 E I

Lc3

2.324kN

Fcol min Mn VnCol P 2.324kN

Fffac 5 Fcol 11.619 kN

Rac Fffac 11.619kN


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5.4 Longitudinal Bracing Capacity – Ground Floor

Gridlines A & D (and the timber framed wall on gridline B in the Central Block) are the same as on the upper level, only

the wall height varies.

The capacities according to MoE Guidelines are (multiply capacity with height factor 2.4m/h):

height ground floor

height factor for ground floor

GS 1 Capacity

GS2 Capacity

Wall Capacities per Gridline

GL A - End Block

GL D - End Block

hgf 3.4m

fgf 2.4m

hgf

0.706

GS1 3kN

m

GS2 4.25kN

m

lagf 2 6.35 m 12.7m

Ragf

lagf

2fgf GS1 13.447kN

ldgf 2 6.35 m 12.7m

Rdgf

ldgf

2fgf GS1 13.447kN


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Concrete Shear Walls

The staircase walls on the ground floor are 7.21m long 8” concrete walls each.

Concrete Shear Calculation (NZS3101:2006: Section 9)

Wall dimensions Reinforcement

Wall length diameter

Wall depth spacing

Area of Shear Reo

Shear Capacity

Reduction Factor

Effective Shear Area

Nominal Concrete Strength

Nominal Reo Strength

Total Shear Capacity per Wall

GL B & C - End Block

bw 7210mm ds 0.5in 12.7 mm

dw 200mm ss 300mm

Av

ds2

4126.677mm

2

0.85

fcc 25MPa

fy 300MPa

Acv bw 0.8 dw 1.154m2

Vc 0.17fcc

1MPa Acv 1 MPa 833.476kN

Vs Av fy 0.8bw

ss

621.071kN

Vn Vc Vs 1.455MN

Rbconc Vn 1.455MN

Rcconc Vn 1.455MN


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Overturning

Considering the relative stiffness of the concrete walls, apply all loads in End Block to concrete walls: Each Wall receives ½ of Total End Block Loads for μ = 1.25:

Wall Capacity, calculation on following pages

Wall Demand

Wall Capacity is adequate

Mcw 4321kN m

Mdcw Fe1.25r Fe1.25f 0.5 3.65 m 871.483kN m


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Project/Job:


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GL A+

Bracing is to be provided through new Gib GS2 as calculated for the annex structure. This bracing does

not extend full height up to the first floor. Seismic load is transferred from the floor diaphragm to the

bracing wall through cantilever action from the timber columns. The capacity of both the columns and the

wall therefore needs to be calculated to determine the critical bracing capacity.

Wall Capacity:

There is a surplus capacity of 282 bracing units from the annex structure determined on page 64 for earthquake loading which will be utilised to resist lateral loads from the central block in the longitudinal direction. Total bracing line capacity along GL A+ is:

GL A+

Wall capacity

Fgfa 14.1 kN


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Column Capacity GL A+ Ground Floor

The columns are 14” Deep x 8” Wide (355.6mm x 203.2mm) consisting of 4 individual timber members (each

2” x 8”) spliced together (as shown below).

The clear storey height is ~0.50m. Need to check the section and drift capacity of the columns. Since the

columns are subject to relatively significant axial loading demands, consider the combined axial and flexural

actions.



Conservative

Assume Rimu


0.8

k1 1.0 EQLoading( )

k4 1.26

k5 1.0

Lay 500mm

b 203.2mm

d 50.8mm

k8 1.0

fb 19.8MPa

Zb d

2

68.74 10

4 mm

3


Void


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Assume Rimu






NcCol 4 k1 k8 fc Ac

k1 1.0 EQLoading( )

fc 20.1MPa

Lax 3400mm

Lay 500 mm

S3 Lay d 9.843

S2 Lax b 16.732

k8 0.82

Ac d b 1.032 104

mm2


Wtotcb 373.834kN

Acbf 194.776m2

ta 4.41m7.57m

2 16.692m

2

Nx

ta

Acbf

Wtotcb 32.037kN

UNcol

Nx

NcCol

0.059

Bef 1.0 UNcol 0.941




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Critical Column Capacity

Column Capacity Gridline A+

Column Capacity exceeds Wall capacity in this case, Wall capacity governs

Wall Capacity Gridline A+ Ground Floor

VnCol 4 k1 k4 k5 fs As

fs 3.8MPa

As2

3b d 6.882 10

3 mm

2


max 2.5% Lay 12.5 mm

P Lc3

3 E I( )

E 9500MPa

Ib d

3

122.22 10

6 mm

4

Lc Lay 0.5 m

P4 max3 E I

Lc3

25.307kN


Fgfa 5 Fcol 65.667 kN

Fgfa Rapgf 56.72kN


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GL C+

Wall Capacity

Check Column capacity to determine which governs.

height ground floor

Since the height of the walls is below 2.4m the height factor will be 1.0

height factor for ground floor

GS 1 Capacity

hgf 2.7m

fgf 1.0

GS1 3kN

m

lcpgf 10.97m 10.3m 21.27m

Rcpgf lcpgf fgf GS1 63.81kN


Project/Job:


246313


Column Capacity:

The columns are 14” Deep x 8” Wide (355.6mm x 203.2mm) consisting of 4 individual timber members (each




Conservative

Assume Rimu


0.8

k1 1.0 EQLoading( )

k4 1.26

k5 1.0

Lay 2200mm

b 203.2mm

d 50.8mm

k8 1.0

fb 19.8MPa

Zb d

2

68.74 10

4 mm

3


Void


Project/Job:


246313




Assume Rimu






NcCol 4 k1 k8 fc Ac

k1 1.0 EQLoading( )

fc 20.1MPa

Lax 3400mm

Lay 2.2 103

mm

S3 Lay d 43.307

S2 Lax b 16.732

k8 0.177

Ac d b 1.032 104

mm2


Wtotcb 373.834kN

Acbf 194.776m2

ta 4.41m7.57m

2 16.692m

2

Nx

ta

Acbf

Wtotcb 32.037kN

UNcol

Nx

NcCol

0.273

Bef 1.0 UNcol 0.727




Project/Job:


246313








Column Capacity Gridline C+

Column Capacity is lower than the Wall capacity in this case, column capacity governs


fs 3.8MPa

As2

3b d 6.882 10

3 mm

2


max 2.5% Lay 55 mm

P Lc3

3 E I( )

E 9500MPa

Ib d

3

122.22 10

6 mm

4

Lc Lay 2.2 m

P4 max3 E I

Lc3

1.307kN


Fgfc 5 Fcol 6.536kN


Project/Job:


246313


5.5 Longitudinal Capacity Summary

First Floor

Central Block

GL A+

GL C+

End Block

GL A

GL B

GL C

GL D

Ground Floor

Central Block

GL A+

GL C+

End Block

GL A

GL B

GL C

GL D

Fffac 11.619 kN

Fffac 11.619 kN

Ra 14.99 kN

Reb 24.112 kN

Rc 24.112kN

Rd 14.99kN

Fgfa 14.1 kN

Fgfc 6.536kN

Ragf 13.447 kN

Rbconc 1.455 MN

Rcconc 1.455 MN

Rdgf 13.447 kN


Project/Job:


246313


5.6 Transverse Bracing Capacity – First Floor

Assessing existing bracing capacities:

- GL 1, 2, 7, 8 – End Block

Wall mainly consists of glazing along this wall with spandrel panels constructed of sarking that extend only

a partial height (1.07m) up the walls and 4 Type A columns.

Nail capacity (from NZS 3603:1993):

ϕ =3.15, J4 timber, Rimu

Seismic Loading

per Nail

Manual - “ Assessment and Improvement of the Structural Performance of Buildings in Earthquakes” ):

2 Nails

Length of Wall GL 1 & 8

6 inch boards

Length of Wall GL 2 & 7

Nnail 0.863kN

0.8

k1 1.0

Nn Nnail k1 0.69 kN

n 2

Ln 9.15m

bn 150mm

Rsw18 0.5 Nn n Ln 2 bn 21.057kN

Ln 7.6m

Rsw27 0.5 Nn n Ln 2 bn 17.49kN


Project/Job:


246313


Column Capacity:

The columns are 14” Deep x 5” Wide (355.6mm x 127mm) consisting of 4 individual timber members (each




actions.



Conservative

Assume Rimu


0.8

k1 1.0 EQLoading( )

k4 1.26

k5 1.0

Lay 1650mm

b 127mm

d 50.8mm

k8 1.0

fb 19.8MPa

Zb d

2

65.462 10

4 mm

3


Void


Project/Job:


246313




Assume Rimu






NcCol 4 k1 k8 fc Ac

k1 1.0 EQLoading( )

fc 20.1MPa

Lax 3400mm

Lay 1.65 103

mm

S3 Lay d 32.48

S2 Lax b 26.772

k8 0.32

Ac d b 6.452 103

mm2


Wtoteb 480.746kN

Aebf 136.949m2

ta 4.41m7.57m

2 16.692m

2

Nx

ta

Aebf

Wtoteb 58.595kN

UNcol

Nx

NcCol

0.441

Bef 1.0 UNcol 0.559




Project/Job:


246313








Column Capacity Gridlines 1, 2, 7 & 8


Gridline 1 & 8 Capacity



fs 3.8MPa

As2

3b d 4.301 10

3 mm

2

k4 1.24


max 2.5% Lay 41.25 mm

P Lc3

3 E I( )

E 9500MPa

Ib d

3

121.387 10

6 mm

4

Lc Lay 1.65 m

P4 max3 E I

Lc3

1.452kN


F1278 4 Fcol 5.81 kN

F18 F1278 5.81 kN

F27 F1278 5.81 kN


Project/Job:


246313


5.7 Transverse Bracing Capacity – Ground Floor

- GL 1 & 8

Wall mainly consists of glazing along this wall with spandrel panels constructed of sarking that extend only

a partial height up the walls and 4 Type A columns. (See GL1,2,7,8).

Column Capacity:





actions.


Wall capacity


Conservative

Assume Rimu

Rswgf 2 Rsw18 42.114kN


0.8

k1 1.0 EQLoading( )

k4 1.24

k5 1.0

Lay 3400mm

b 127mm

d 50.8mm

k8 1.0

fb 19.8MPa

Zb d

2

65.462 10

4 mm

3


Void


Project/Job:


246313




Assume Rimu






NcCol 4 k1 k8 fc Ac

k1 1.0 EQLoading( )

fc 20.1MPa

Lax 2200mm

Lay 3.4 103

mm

S3 Lay d 66.929

S2 Lax b 17.323

k8 0.177

Ac d b 6.452 103

mm2


Wtoteb 480.746kN

Aebf 136.949m2

ta 4.41m7.57m

2 16.692m

2

Nx

ta

Aebf

Wtoteb 58.595kN

UNcol

Nx

NcCol

0.798

Bef 1.0 UNcol 0.202


Mn Mnco2 Lax 0.395 kN


Project/Job:


246313








Column Capacity Gridlines 1 & 8




fs 3.8MPa

As2

3b d 4.301 10

3 mm

2

k4 1.24


max 2.5% Lax 55 mm

P Lc3

3 E I( )

E 9500MPa

Ib d

3

121.387 10

6 mm

4

Lc Lax 2.2 m

P4 max3 E I

Lc3

0.817kN


Fgf18 4 Fcol 1.578 kN

Fgf18 1.578 kN


Project/Job:


246313


GL 2 & 7

Plasterboard Wall Capacity:

Bracing is provided through a 7.6m long, 2.7m high timber framed shear wall. The shear wall does not extend

full height up to the first floor. As with the wall on GL C+, seismic load is transferred from the floor diaphragm

to the bracing wall through cantilever action from the timber columns. The capacity of both the columns and

the wall therefore needs to be calculated to determine the critical bracing capacity. The upper part of the

building is 7.6 m of

Wall Capacity:

The wall along this grid line does not appear to have any sarking. The wall is framed with 4”x2” timber and

lined with plasterboard.

Assume bracing capacity of 50Bu/m = 2.5 kN/m


Project/Job:


246313


Wall height

Wall Capacity per meter

GL 2

Wall length

Height factor

GL 7

h 2.7m

Cap 2.5kN

m

l 7.6m

f 1h

l2if

h

lotherwise

1

Rgfgl2 Cap f l 19 kN

Rgfgl7 Cap f l 19 kN


Project/Job:


246313


GL 2 & 7 Columns


2” x 5”) spliced together (as shown below) with voids in-between the timber members.



actions.


Conservative

Assume Rimu


0.8

k1 1.0 EQLoading( )

k4 1.24

k5 1.0

Lay 3400mm

b 127mm

d 50.8mm

k8 1.0

fb 19.8MPa

Zb d

2

65.462 10

4 mm

3


Void


Project/Job:


246313




EQ Loading

Assume Rimu






NcCol 4 k1 k8 fc Ac

k1 1.0

fc 20.1MPa

Lax 500mm

Lay 3.4 m

S3 Lay d 66.929

S2 Lax b 3.937

k8 0.42

Ac d b 6.452 103

mm2


Wtoteb 480.746kN

Aebf 136.949m2

ta 4.41m7.57m

2 16.692m

2

Nx

ta

Aebf

Wtoteb 58.595kN

UNcol

Nx

NcCol

0.336

Bef 1.0 UNcol 0.664


Mn Mnco2 Lax 5.697 kN


Project/Job:


246313








Column Capacity Gridlines 2 & 7

Column Capacity is higher than the Wall capacity in this case, wall capacity governs



fs 3.8MPa

As2

3b d 4.301 10

3 mm

2

k4 1.24


max 2.5% Lax 12.5 mm

P Lc3

3 E I( )

E 9500MPa

Ib d

3

121.387 10

6 mm

4

Lc Lax 0.5 m

P4 max3 E I

Lc3

15.817kN


Fgf27 4 Fcol 22.79 kN

Fgf27 Rgfgl2 19 kN


Project/Job:


246313


Out of Plane Capacity of Concrete Shear Walls

Wall thickness

Width of shear surface, (vertical bar spacing)

Width of load surface

Reo Diameter

Reinforcement Area

Shear Capacity

Effective Shear Area

Nominal Concrete Strength

Nominal Reinforcement Strength

Capacities

Total Out of Plane Shear Capacity

Moment Capacity

Demands

Unit weight of 8in Wall

Wall weight

t 8in 203.2mm

dop 0.9 t 182.88mm

ssh 300mm

bsh 1000mm

fcc 25 MPa

ds 12.7 mm

As

bsh

ssh

ds2

4 422.256mm

2

0.85

Acv bsh 0.8 dop 1.463 103

cm2

Vc 0.17fcc

1MPa Acv 1 MPa 105.705kN

Vs As fy 0.8bsh

ssh

287.134kN

Vn Vc Vs 392.839kN

Mn As fy dop 23.167kN m

WUcw 24kN

m3

t 4.877kPa

Wshear WUcw bsh Cd1.25 4.844kN

m

Wflex WUcw bsh Cd2.0 2.666kN

m


Project/Job:


246313


Reinforcement tied into foundation wall strips, allowing for cantilever action of walls in out-of-plane.

Assuming cantilever action for demand (Conservative)

Transverse Capacity per Wall (assume loads at full height)

Mcanti Wflex3.65m( )

2

2 17.76kN m

Vcanti Wshear 3.65 m 17.681kN

Ccwt Mn 3.65m( ) 6.347 kN


Project/Job:


246313


5.8 Transverse Capacity Summary

Breakout of classrooms results in no lateral load resisting walls in the central block. New central block lateral load resisting

elements for the ground and first floor are to be designed in subsequent sections based on the preliminary bracing scheme

for Option 1.

First Floor

End Block

GL 1 & 8

GL 2 & 7

Ground Floor

End Block

GL 1 & 8

GL 2 & 7

F18 5.81 kN

F27 5.81 kN

Fgf18 1.578 kN

Fgf27 19 kN


Project/Job:


246313


5.9 Roof Diaphragm capacity

The roof diaphragm for both the Central Block and the End Blocks is made up of diagonal sarking, with a

capacity of;

Croof = 10.5kN/m

This is the capacity suggested in Table 11.1 in the NZSEE Publication “Assessment and Improvement of

the Structural Performance of Buildings in Earthquakes”.


Project/Job:


246313


Roof Demands ( = 2.5):

Dimensions and Capacity

Central Block Length

Central Block Width

Central Block roof capacity

Central Block Roof Demand

End Block Length

End Block Width

End Block roof capacity

End Block Roof Demand

l 22.07m

w 7.57m

Ccb Croof w 79.485kN

Dcb

Fc2.5r

227.669kN

l 22.07m

w 6.35m

Ceb Croof w 66.675kN

Deb

Fe2.5r

229.818kN

29.8kN

59.6kN

29.8kN

55.4kN

27.7kN 27.7kN

7.57m

22.07m

6.35m

22.07m


Project/Job:


246313


5.10 Floor Diaphragm Capacities

First Floor

The first floor diaphragm is constructed out of timber tongue and groove sheathing.

Timber tongue and groove floor diaphragms have the following capacity;

Cfloor = 0.76 kN/m = 4.20 kN/m

This is the capacity suggested in Table 11.1 in the NZSEE Publication “Assessment and Improvement of

the Structural Performance of Buildings in Earthquakes”.


Project/Job:


246313


First Floor Dimensions:

- First Floor Capacities

Longitudinal

First Floor Central Block

First Floor End Block

Transverse

First Floor Central Block

First Floor End Block

Ccbfl 22.07m Cfloor 92.694kN

Cebfl 2 6.35 m Cfloor 53.34kN

Ccbft 7.57m Cfloor 31.794kN

Cebft 2 9.14 m Cfloor 76.776kN

6.35m

3.05m

9.14m

9.14m

25.73m

7.57m

m

21.33m

Transverse

Longitudinal

7.19m 10.85m

22.07m


Project/Job:


246313


Local Diaphragm Demands

The shear demands on the diaphragm are based on the tributary widths between the lateral bracing

elements.

The critical tributary widths are shown below:


Project/Job:


246313


- Critical shear in diaphragm

Longitudinal

Central Block

Central Block Critical Span

Central Block Total Span

Central Block Demand

End Block

End Block Critical Span

End Block Total Span

End Block Demand

Longitudinal

Central Block

Central Block Critical Span

Central Block Total Span

Central Block Demand

End Block

End Block Critical Span

End Block Total Span

End Block Demand

Capacity > Demand --> 100%NBS

lcrit 22.07m

l 22.07m

Dcbfl 0.5Fc2.5flcrit

l 31.21kN

lcrit 9.14m

l 21.33m

Debfl 0.5Fe2.5flcrit

l 19.668kN

lcrit 10.85m

l 22.07m

Dcbft 0.5Fc2.5flcrit

l 15.343kN

lcrit 6.35m

l 6.35m

Debft 0.5Fe2.5flcrit

l 45.9kN


Project/Job:


246313


Ground Floor

As with the First Floor, the ground floor diaphragm is constructed out of timber tongue and groove sheathing.

Hence; F = 0.76kN/m = 4.20 kN/m; (as per NZSEE Publication)

Since all of the bracing walls rest on top of foundation walls, the ground floor diaphragm is required to resist

seismic loading generated from the weight of the floor diaphragm only.

It was found that the first floor diaphragm could adequately resist seismic demands in accordance with 67%

of NZS 1170.5 at that level. Since the ground floor diaphragm has a bracing capacity equivalent to the first

floor and the loading demands through the ground floor diaphragm will be lower, the ground floor diaphragm

will also have an adequate capacity to resist seismic demands in accordance with NZS 1170.5.


Project/Job:


246313


5.11 Summary of Capacities for Option 1

Longitudinal Capacities

Central Block

First Floor

End Block

GL A

GL B

GL C

GL D

GL A+

GL C+

End Block

GL A

GL B

GL C

GL D

Ground Floor

Central Block

GL A+

GL C+

Ragf 13.447 kN

Rbconc 1.455 MN

Rcconc 1.455 MN

Rdgf 13.447 kN

Fffac 11.619 kN

Fffac 11.619 kN

Ra 14.99 kN

Reb 24.112 kN

Rc 24.112kN

Rd 14.99kN

Fgfa 14.1 kN

Fgfc 6.536kN


Project/Job:


246313


Transverse Capacities

Floor Capacities

First Floor

End Block

GL 1 & 8

GL 2 & 7

Ground Floor

End Block

GL 1 & 8

GL 2 & 7

Longitudinal

Central Block

End Block

Transverse

Central Block

End Block

F18 5.81 kN

F27 5.81 kN

Fgf18 1.578 kN

Fgf27 19 kN

Ccbfl 92.694 kN

Cebfl 53.34 kN

Ccbft 31.794 kN

Cebft 76.776 kN


Project/Job:


246313


%NBS Capacities

Determine the capacity of the structure in terms of a percentage of loading demands calculated in

accordance with NZS 1170.5 (%NBS).

Seismic Demands

The seismic demands on the structure in accordance with NZS 1170.5 (ductility 2.5) are as follows:

Central Block

Roof Level

First Floor Level

Total

End Block

Roof Level

First Floor Level

Total

Combined

Roof Level

First Floor Level

Total

Fc2.5r 55.338 kN

Fc2.5f 62.42 kN

Fc2.5 Fc2.5r Fc2.5f 117.758kN

Fe2.5r 59.636 kN

Fe2.5f 91.8 kN

Fe2.5 Fe2.5r Fe2.5f 151.436kN

F2.5r Fc2.5r 2 Fe2.5r 174.61kN

F2.5f Fc2.5f 2 Fe2.5f 246.02kN

F2.5 F2.5r F2.5f 420.63kN


Project/Job:


246313


Roof Forces (100% NZS 1170.5 - Ductility 2.5)

First Floor Forces (100% NZS 1170.5 - Ductility 2.5)

59.64 kN

55.34 kN

59.64 kN

91.8kN (+ Roof Forces

Above)


Above)

(+ Roof Forces

Above)


Above)


Project/Job:


246313


Longitudinal Bracing Capacities

First Floor

Central Block

Total Capacity

Total Demand

%NBS

End Block

Total Capacity

Total Demand

%NBS

Ground Floor

Central Block

Total Capacity

Total Demand

%NBS

End Block

Total Capacity

Total Demand

%NBS

The majority of the longitudinal bracing is provided in the two end blocks. Assume µ =1.25 for lower level demands in End Block due to concrete walls.

Ccbffl 2 Fffac 23.239 kN

Fc2.5r 55.338 kN

NBSffcb Ccbffl Fc2.5r 41.994%

Cebffl Ra Reb Rc Rd 78.205kN

Fe2.5r 59.636 kN

NBSffeb Cebffl Fe2.5r 131.137%

Ccbgfl Fgfa Fgfc 20.636 kN

Fc2.5 117.758kN

NBSgfcb Ccbgfl Fc2.5 17.524%

Cebgfl Ragf Rbconc Rcconc Rdgf 2.936MN

Fe1.25 Fe1.25f Fe2.5r 335.617kN

NBSgfeb Cebgfl Fe1.25 874.803%


Project/Job:


246313


Transverse Bracing Capacities

Seismic demands in the End Blocks are resisted by bracing on Grid Lines 1, 2, 7 and 8.

Breakout of classrooms results in no lateral load resisting walls in the central block. New central block lateral

load resisting elements for the ground and first floor are to be designed in section 7 and 10.

First Floor

Central Block

Total Capacity

Total Demand

%NBS

End Block

Total Capacity

Total Demand

%NBS

Ground Floor

Central Block

Total Capacity

Total Demand

%NBS

End Block

Total Capacity

Total Demand

%NBS

Ccbfft 0 0 kN

Fc2.5r 55.338 kN

NBSffcbt Ccbfft Fc2.5r 0 %

Cebfft F18 F27 11.619kN

Fe2.5r 59.636 kN

NBSffebt Cebfft Fe2.5r 19.484%

Ccbgft 0 0 kN

Fc2.5 117.758kN

NBSgfcbt Ccbgft Fc2.5 0 %

Cebgft Fgf18 Fgf27 20.578kN

Fe2.5 Fe2.5f Fe2.5r 151.436kN

NBSgfebt Cebgft Fe2.5 13.589%


Project/Job:


246313


Roof Diaphragm Capacities

Floor Diaphragm Capacities

Central Block

End Block

Longitudinal

Transverse

Central Block

End Block

Central Block

End Block

NBSrc

Ccb

Dcb

287.271%

NBSre

Ceb

Deb

223.607%

NBSfcl

Ccbfl

Dcbfl

297.001%

NBSfel

Cebfl

Debfl

271.197%

NBSfct

Ccbft

Dcbft

207.216%

NBSfel

Cebft

Debft

167.268%


Project/Job:


246313


5.12 Critical Seismic Capacities

Longitudinal

Central Block

First Floor

Ground Floor

End Block

First Floor

Ground Floor

Transverse

Central Block

First Floor

Ground Floor

End Block

First Floor

Ground Floor

NBSffcb 41.994%

NBSgfcb 17.524 %

NBSffeb 131.137%

NBSgfeb 874.803%

NBSlong min NBSffcb NBSgfcb NBSffeb NBSgfeb 17.524%

NBSffcbt 0 %

NBSgfcbt 0 %

NBSffebt 19.484%

NBSgfebt 13.589 %

NBStrans min NBSffcbt NBSgfcbt NBSffebt NBSgfebt 0 %


Project/Job:


246313


6. Load transfer between Central Block & End Block

The inspection of Mairehau High School in Christchurch has revealed that the Central Block and End Blocks are

connected and do allow for load transfer between the blocks. The roof is actually continuous and the step down on the

drawings between the central block and the end blocks is not to be found on the actual building. Furthermore the diagonal

bracing from the ceilings also connects the central block to the end blocks. The diaphragm of the first floor is continuous

from the end block into the central block with no gaps where the two sections meet. This allows for a load transfer

between the sections and raises overall capacity accordingly.

Two destructive tests carried out at the Mairehau High School and Upper Hutt College have confirmed that the End Block

and the Central Block are adequately tied together to allow for load transfer between the blocks. This has been

considered for final %NBS scores.

s

Capacities for Option 1:

Longitudinal Capacity

First Floor

Total Demand First Floor

Total Capacity First Floor

%NBS First Floor

Ground Floor

Total Demand Ground Floor

Total Capacity Ground Floor

%NBS Ground Floor

Transverse Capacity

First Floor



%NBS First Floor

Ground Floor



%NBS Ground Floor

F2.5r 174.61 kN

Cfirst Ccbffl 2 Cebffl 179.648kN

NBSlfirst min Cfirst F2.5r 100% 100 %

F2.5 420.63kN

Cground Ccbgfl 2 Cebgfl 5.893 MN

NBSlground min Cground F2.5 100% 100 %

F2.5r 174.61 kN

Ctfirst Ccbfft 2 Cebfft 23.239kN

NBStfirst min Ctfirst F2.5r 100% 13.309%

F2.5 420.63kN

Ctground Ccbgft 2 Cebgft 4 Ccwt 0.079MN

NBStground min Ctground F2.5 100% 18.838%


Project/Job:


246313


7. Increasing Lat. Bracing Cap. to 67% of NZS 1170.5

requirements for Option 1

In order to meet the requirements of the current standards, Nelson Block structures are to be strengthened

to a minimum of 67% of NZS 1170.5 code requirements (67% NBS).

The strengthening scheme assumes there is load transfer between the Central Block and the End Blocks.

Since the longitudinal direction on both floors is over 67%NBS only the transverse direction on both levels

will have to be strengthened.

7.1 Loading Demands

The loading demands at 67% NBS (= 2.5) are shown below:

Central Block & End Block

67% First Floor

67% Ground Floor

F2.5r67 0.67 F2.5r 116.989kN

F2.567 0.67 F2.5 281.822kN


Project/Job:


246313




116.99 kN

281.82 kN


Project/Job:


246313


Capacity Shortfalls

Determine the required strengthening demands to bring the structure to 67% NBS.

Transverse Direction Only

First Floor

Capacity First Floor

Capacity Shortfall μ = 2.5


Ground Floor

Capacity Ground Floor



Ctfirst 23.239 kN

Sft2.5 F2.5r67 Ctfirst 93.75kN

Sft3.0 Sft2.5 Cd3.0 Cd2.5 81.25 kN

Ctground 79.238 kN

Sgft2.5 F2.567 Ctground 202.584kN

Sgft3.0 Sgft2.5 Cd3.0 Cd2.5 175.573kN


Project/Job:


246313


7.2 First Floor Strengthening

Interior Walls

For Option 1 there are two new small breakout areas on the first floor. This can provide three new walls to

be Gib BLP. These walls are located on gridlines 4, 5 and 5A. Wall lengths are to be taken as 3.5m. A

displacement ductility of 3.0 is to be used for new Gib bracing walls.

GL 4-5A – Central Block

GL 4

Wall height

Wall Capacity per metre for BLP-H

Wall length

GL 5

Wall length

GL 5A

Wall length

hff 3.05m

Cap 5.75kN

m

l 3.5m

Rgl4 Cap f l 20.125kN

l 3.5m

Rgl5 Cap f l 20.125kN

l 3.5m

Rgl5A Cap f l 20.125 kN


Project/Job:


246313


Exterior Walls

The preliminary bracing scheme indicates new BL1-H walls along gridlines 1, 2, 7 and 8. New wall lengths

are to be taken as 3m.

Using 3m of Gib BL1-H achieves 12.3kN of lateral load resistance.

GL 1

GL 2

GL 7

GL 8

Total %NBS is greater than 67%. Therefore BL1-H is suitable.

Capacity of First Floor after installing new Gib walls

Original %NBS First Floor

Total %NBS for first floor (transverse direction)

Rgl1new 12.3kN

Rgl2new 12.3kN

Rgl7new 12.3kN

Rgl8new 12.3kN

NBSfftnew Rgl1new Rgl2new Rgl7new Rgl8new Rgl4 Rgl5 Rgl5A F3.0r 72.409%


NBSffttotal NBSfftnew NBStfirst. 85.718%


Project/Job:


246313


7.3 Ground Floor Strengthening

To achieve a minimum of 67%NBS portal frames will be introduced on gridline 1 & 2 (respectively 7 & 8) as

well as utilising internal walls along gridlines 4, 5, and 5A for Gib BLP.

Interior Walls

GL 4-5A

For Option 1 there are two new small breakout areas on the first floor. This provides three new walls to be Gib BLP. These

walls are located on gridlines 4, 5 and 5A. The wall lengths are to be taken as 3.5m. If these walls and steel portal frames

along gridlines 1, 2, 7 and 8 cannot provide sufficient lateral load resistance then new steel portal frames will need to be

installed along gridlines 3 and 6.

Must provide steel portal frames to achieve a minimum of 67% NBS.

Wall height

Wall Capacity per meter

GL 4

Wall length

GL 5

Wall length

GL 5A

Wall length

Capacity of First Floor after installing new Gib walls:

Original %NBS

Combined %NBS

h 3.4m

Cap 5.15kN

m

l 3.5m

Rgfgl4 Cap f l 18.025kN

l 3.5m

Rgfgl5 Cap f l 18.025kN

l 3.5m

Rgfgl5A Cap f l 18.025kN

NBSgftnew.walls Rgfgl4 Rgfgl5 Rgfgl5A F3.0 16.486%


NBSgfttotal NBSgftnew.walls NBStground. 35.324%


Project/Job:


246313


Portal Frame

To achieve a 67%NBS rating portal frames will be introduced on gridlines 1 & 2 (respectively 7 & 8). Design portal frames

to resist the total shortfall load. Assume a ductility of µ = 1.25 for the Portal Frames.

%NBS required = 67% - 35.3% = 31.7%

Ground Floor Portal Frame Gridlines 1, 2, 7 and 8

Each Portal Frame will have to resist; PFload = 101kN;

Portal Frame Height = 3.65m

Portal Frame Span = 2 x 3.05m (2 Bay)

Choose 300 PFC for the outer columns and beams and 380PFC for the central column.

Moment Demands (via Space Gass)

Converting 32% NBS load for ductility 1.25

Load into portal frame (1 per GL)

F32%.1.25

Cd1.25

Cd2.5

F2.5 0.32

404.659kN

PFload.

F32%.1.25

4

101.165kN


Project/Job:


246313


Shear Demands (via Space Gass)

Axial Demands (via Space Gass)


Project/Job:


246313


Lateral Deflection Limit

Deflection limit is 2.5% of storey height

dmax = 2.5% 3.65m = 91.250mm

Scale deflections due to ductility factor; =1.25 (NZS 1170.5, Section 7.2.1.1) and apply drift modification

factor; kdm=1.2 for structures less than 15m tall (NZS 1170.5, Section 7.3.1.1)

dfmax = dmax / ( kdm) = 60.83mm

Deflections (via Space Gass)

Maximum Deflection 39.7mm < dfmax = 60.83mm


Project/Job:


246313


Under SLS Loading

SLS loads have been scaled from ULS loads based on horizontal seismic coefficients determined in section 2.3. ULS Cd1.25= 0.947 and SLS Cd1.0 = 0.1575. Ratio of SLS and ULS loads = 0.1575/0.947 = 0.17. Lateral deflection = 6.75mm = Height/541 < Height/400 limit. Therefore SLS deflections are okay.


Project/Job:


246313


Portal Floor Connection

Total Shear Demand in Portal Frame; Qtot = (PFload/(3.05m))/2 = 16.6 kN/m

Coach Bolt

Assume Radiata Pine (J5) (Conservative)

Shear Capacity; Qn = k1k12k13kQsk; NZS 3603:1993-Section 4.5.2

k1 = 1.0; EQ Load (Table 2.4)

k12 = 1.0; (Table 4.14, dry)

k13 = 1.0; (Table 4.15)

k = (40mm/(1012mm)) = 0.33; (For 12mm Diameter Screw)

Qsk = 10.4 kN; (Table 4.10, 2b =90mm)

Hence; Qn =2 0.7 k1k12k13kQsk = 4.85kN; (2 Rods)

With 1 coach bolt @ 250 crs; Qntot = 1000mm/250mm Qn = 19.41kN


Project/Job:


246313


MemDes Calculations for 300 PFC Portal Frame Column

Section : 300PFC Grade 300+

Major Axis Bending

Design Action M*x = 91.3 kNm

am = 1.82

as = 0.51

am as < 1.0, => Segment NOT Fully Restrained

Mbx = 1.82 * 0.51 * 169.2 = 157.6

Major axis capacity Ratio = M*x / f Mbx

= 0.64, ---- OK ----

Shear Calculations (Unstiffened Web)

Design Action V*x = 25.0 kN

Nominal Shear Yield capacity Vw = 460.8 kN

av = 4.17 >= 1.0 => full web shear capacity

Vu = Vw = 460.8 kN

Shear capacity ratio = V*x / f Vu

= 0.06, ---- OK ----

Axial Calculations


= 1577.6 kN

Major axis buckling : Minor axis buckling : Minimum Capac. Ncmin = 457.8


= 0.147, ---- OK ----

Combined Actions Checks

Clause 8.3.3/4 :

Mry = Msy (1 - (N*/ f Ns) ) =< Msy [Alt. Prov. NOK]

= 23.6

Load / Capacity Ratio = M*x / (0.9 Mr

x)

= 0.63, ---- OK ----

Clause 8.4.2.2 : Major : Mix = 161.2

Load / Capacity Ratio = M*m/ f Mi

= 0.629 ---- OK ----


Project/Job:


246313


Clause 8.4.4.1 :

Mox = Mbx (1- N* / f Ncy) =< Mrx

= 134.4

Load / Capacity Ratio = M*x / f Mox,

= 0.755, ---- OK ----

======================== SUMMARY =====================


============================================================

MemDes Calculations for 300 PFC Portal Frame Beam


Major Axis Bending


am = 2.43

as = 0.54

am as >= 1.0, => Segment Fully Restrained

Mbx = Msx = 169.20 kNm


= 0.61, ---- OK ----





Vu = Vw = 460.8 kN


= 0.15, ---- OK ----

Axial Calculations


= 1577.6 kN

Major axis buckling : Minor axis buckling : Minimum Capac. Ncmin = 599.1


= 0.016, ---- OK ----


Loading PASSES Cl 8.1.4, => Combined Actions Checks are not required

======================== SUMMARY =====================


============================================================


Project/Job:


246313




Major Axis Bending


am = 1.82

as = 0.55


Mbx = 1.82 * 0.55 * 264.9 = 263.7


= 0.79, ---- OK ----





Vu = Vw = 729.6 kN

Shear capacity ratio = V*x / f Vvm

= 0.08, ---- OK ----

======================== SUMMARY =====================


============================================================


Project/Job:


246313


Portal Frame Details

- Floor Connection Detail

Portal Knee Detail


Project/Job:


246313


Portal Frame Footing

Assumed ground bearing capacity of 250 kPa.

Minimum footing size (N = 68 kN); Afooting = 60.5kN/250kPa = 0.242 m2

Footing size; a = b = 600mm


Project/Job:


246313


Final Bracing Configuration for Option 1


Project/Job:


246313


8. Flexible Learning Space (FLS) Option 2

8.1 Overview/Bracing Scheme

The preliminary bracing scheme is shown in the figure below.

Justify the preliminary structural scheme is adequate to resist lateral loading demands. The critical areas to check are

as follows:

Transverse Direction:

o New two-storey steel portal frames

o New Gib BL1-H on the ground floor

o New Ecoply EP1 walls on the first floor

Longitudinal Direction:

o New Gib bracing walls on bracing lines A+ and A

Apart from modification of walls along gridline A+ and A there is no other difference in the lateral load capacity in the

longitudinal direction found in Option 1. Therefore calculations for the longitudinal direction from Option 1 are the same

and only summary of results will be shown for Option 2.


Project/Job:


246313


8.2 Option 2 Annex Structure

The Annex structure highlighted on page 5 has a separate roof diaphragm and is therefore structurally independent from

main Nelson Block structure. The preliminary bracing scheme for Option 2 on the previous page shows new Gib walls

for lateral bracing of the modified Annex structure. GIB EzyBrace spreadsheets are to be used to determine if the bracing

scheme is sufficient. This is suitable as the Annex structure is independent from the main building, constructed out of

lightweight timber and single storey.

Wall bracing along gridline A+ will resist lateral loads in the longitudinal direction from both the Annex structure and the

central block.


Project/Job:


246313


Total surplus capacity Capsurplus = 3027-2211= 816

This surplus capacity is used to resist lateral loading in the longitudinal direction for the central block by load transfer along gridline A+. Total surplus capacity of 816 BU equates to 40.8kN.


Project/Job:


246313


Gib BL1-H is found to be adequate.


Project/Job:


246313


9. Summary of Existing Capacities for Option 2

Longitudinal Capacity

First Floor



%NBS First Floor

Ground Floor



%NBS Ground Floor

Transverse Capacity

First Floor



%NBS First Floor

Ground Floor



%NBS Ground Floor

F2.5r 174.61 kN

Cfirst Ccbffl 2 Cebffl 179.648kN

NBSlfirst min Cfirst F2.5r 100% 100 %

F2.5 420.63kN

Cground Ccbgfl 2 Cebgfl 5.935 MN

NBSlground min Cground F2.5 100% 100 %

F2.5r 174.61 kN

Ctfirst Ccbfft 2 Cebfft 23.239kN


F2.5 420.63kN

Ctground Ccbgft 2 Cebgft 4 Ccwt 0.079MN



Project/Job:


246313


10. Increasing Lat. Bracing Cap. to 67% of NZS 1170.5

requirements for Option 2

In order to meet the requirements of the current standards, Nelson Block structures are to be strengthened

to a minimum of 67% of NZS 1170.5 code requirements (67% NBS).

The strengthening scheme assumes there is load transfer between the Central Block and the End Blocks.

Since the longitudinal direction on both floors is over 67%NBS only the transverse direction on both levels

will have to be strengthened.

10.1 Loading Demands

The loading demands at 67% NBS (= 2.5) are shown below:

Central Block & End Block

67% First Floor

67% Ground Floor

F2.5r67 0.67 F2.5r 116.989kN

F2.567 0.67 F2.5 281.822kN


Project/Job:


246313




116.99 kN

281.82 kN


Project/Job:


246313


Capacity Shortfalls

Determine the required strengthening demands to bring the structure to 67% NBS.

Transverse Direction Only

First Floor

Capacity First Floor



Ground Floor

Capacity Ground Floor



Ctfirst 23.239 kN

Sft2.5 F2.5r67 Ctfirst 93.75kN

Sft3.0 Sft2.5 Cd3.0 Cd2.5 81.25 kN

Ctground 79.238 kN

Sgft2.5 F2.567 Ctground 202.584kN

Sgft3.0 Sgft2.5 Cd3.0 Cd2.5 175.573kN


Project/Job:


246313


11. Option 2 Seismic Strengthening

End blocks are to be strengthened using GIB bracing walls and steel portal frames along gridlines 1, 2, 7

and 8 for the first and ground floor respectively. The central block will be strengthened with four two-storey

steel portal frames, each along gridlines 3, 4, 5 and 6. The roof level and first floor demands for the steel

portal frames will be determined based on the shortfall load required after using GIB walls and steel portal

frames for the end blocks.

11.1 End Block First Floor Strengthening

Walls

As indicated in the preliminary bracing scheme install new Ecoply EP1 walls along gridlines 1 and 8. New

wall lengths are 3.4m. Displacement ductility of 3.0 is to be used for new bracing walls.

Using 3.4m of Ecoply EP1 achieves 16.05kN of lateral load resistance.

GL 1

GL 8

Design new steel portal frames along gridlines 3, 4, 5 and 6 to achieve a minimum of 67% NBS.

Original first floor %NBS in transverse direction

%NBS of new Gib walls

Combined %NBS of new walls and existing bracing

Rgl1new 16.05kN

Rgl8new 16.05kN

NBStfirst. 13.309 %

NBSfftnew Rgl1new Rgl8new F3.0r 21.212%

NBSffttotal NBSfftnew NBStfirst. 34.521%


Project/Job:


246313


To achieve a minimum of 67%NBS portal frame must resist:

%NBS required = 67% - 34.5% = 32.5%

Converting 33%NBS load for ductility 1.25

Load into each portal frame at the roof level (4 total)

F33%.1.25

Cd1.25

Cd2.5

F2.5r 0.33

173.23kN

PFload.

F33%.1.25

4

43.307kN


Project/Job:


246313


11.2 End Block Ground Floor Strengthening

The same design used for the steel portal frames in the end blocks for Option 1 will be used.

Portal Frame Height = 3.65m

Portal Frame Span = 2 x 3.05m (2 Bay)

Use 380 PFC for central column and 300PFC for exterior columns and beams. The allowable lateral load

capacity is 120kN. Beyond this limit the member capacity for the outer columns will be reached.


To achieve a 67%NBS rating steel portal frames will be introduced on gridlines 1-8 to strengthen end and central blocks.

Assume a ductility of μ = 1.25 for Portal Frames

PFload

Cd1.25

Cd3.0

Sgft3.0

609.038kN


Project/Job:


246313





Project/Job:


246313


Lateral Deflection Limit


dmax = 2.5% 3.65m = 91.25mm

Scale deflections due to ductility factor =1.25 (NZS 1170.5, Section 7.2.1.1) and apply drift modification

factor kdm=1.2 for structures less than 15m tall (NZS 1170.5, Section 7.3.1.1)



Maximum Deflection 47.1mm < dfmax = 60.83mm


Project/Job:


246313


Under SLS Loading

SLS loads have been scaled from ULS loads based on horizontal seismic coefficients determined in section 2.3. ULS Cd1.25= 0.947 and SLS Cd1.0 = 0.1575. Ratio of SLS and ULS loads = 0.1575/0.947 = 0.17. Lateral deflection = 8mm = Height/456 < Height/400 limit. Therefore SLS deflections are okay.


Project/Job:


246313


Portal Floor Connection

Total Shear Demand in Portal Frame Qtot = (PFload/(3.05m))/2 = 19.7 kN/m

Coach Bolt


Shear Capacity Qn = k1k12k13kQsk NZS 3603:1993-Section 4.5.2

k1 = 1.0 EQ Load (Table 2.4)

k12 = 1.0 (Table 4.14, dry)

k13 = 1.0 (Table 4.15)

k = (40mm/(1012mm)) = 0.33 (For 12mm Diameter Screw)

Qsk = 10.4 kN (Table 4.10, 2b =90mm)

Hence Qn =2 0.7 k1k12k13kQsk = 4.85kN (2 Rods)

With 1 coach bolt @ 200 crs Qntot = 1000mm/200mm Qn = 24.25kN


Project/Job:


246313




d = 380 mm b = 100 mm tf = 17.5 mm tw = 10.0 mm


Member Effective Length Calcs

Eff. Len Le = 3.65 * 1.07 * 1.00 * 1.00 = 3.90m

Major Axis Bending


Section Bending Capacity Msx = fyf Zex = 264.88 kNm

User provided value for am = 1.82

Reference Buckling Moment Calculation : Mo

Mo = 222.9 kNm ( Eqtn 5.6.1.1(4) )

as = 0.55


Mbx = 1.82 * 0.55 * 264.9 = 263.7


= 0.93, ---- OK ----





Vu = Vw = 729.6 kN

Mom-Shear Interaction Check : Moment ratio > 0.75 => reduced shear capacity available

Shear capacity ratio = V*x / f Vvm

= 0.13, ---- OK ----

======================== SUMMARY =====================


============================================================


Project/Job:


246313




d = 300 mm b = 90 mm tf = 16.0 mm tw = 8.0 mm



Eff. Len Le = 3.65 * 1.08 * 1.00 * 1.00 = 3.95m

Major Axis Bending



User provided value for am = 1.82


Mo = 126.9 kNm ( Eqtn 5.6.1.1(4) )

as = 0.51


Mbx = 1.82 * 0.51 * 169.2 = 157.9


= 0.76, ---- OK ----





Vu = Vw = 460.8 kN


= 0.07, ---- OK ----

Axial Calculations



= 1577.6 kN


acx < 1.0 => Ncx = acx Ns = 1413.5


acy < 1.0 => Ncy = acy Ns = 457.8



= 0.174, ---- OK ----


Project/Job:


246313



Sig. Axial Load Check ( Cl. 8.1.4 ) : Combined Actions check IS required

+ Check Alternative Provisions, (Clause 8.1.5)

Alt. Prov. Cl 8.1.5 (a)-(c) NOT OK for Minor axis, NOT OK for Major axis actions

Clause 8.3.2/4 :

Mrx = Msx (1 - N* / f Ns) =< Msx, [Alt. Prov. NOK]

= 160.6

Clause 8.3.3/4 :

Mry = Msy (1 - (N*/ f Ns) ) =< Msy [Alt. Prov. NOK]

= 23.4


x)

= 0.75, ---- OK ----

Clause 8.4.2.2 : Major : Mix = Msx (1 - N*/ f Ncx ) =< Mrx

= 159.7


= 0.754 ---- OK ----

Clause 8.4.4.1 :

Mox = Mbx (1- N* / f Ncy) =< Mrx

= 130.4


= 0.924, ---- OK ----

======================== SUMMARY =====================


============================================================


Project/Job:


246313


MemDes Calculations for 300 PFC Portal Frame Beam


d = 300 mm b = 90 mm tf = 16.0 mm tw = 8.0 mm



Eff. Len Le = 3.05 * 1.20 * 1.00 * 1.00 = 3.65m

Major Axis Bending



am = 1.7 * 111.0 / [( 54.0)2 + ( -1.0)2 + ( -56.0)2 ]0.5 = 2.425


Mo = 140.2 kNm ( Eqtn 5.6.1.1(4) )

as = 0.54




= 0.73, ---- OK ----





Vu = Vw = 460.8 kN


= 0.17, ---- OK ----

Axial Calculations



= 1577.6 kN


acx < 1.0 => Ncx = acx Ns = 1458.9


acy < 1.0 => Ncy = acy Ns = 599.1



= 0.019, ---- OK ----


Project/Job:


246313



Significant Axial Load test (Cl. 8.1.4(a)) IS Satisfied ---- OK ----


======================== SUMMARY =====================


============================================================


Project/Job:


246313



- Floor Connection Detail

Portal Knee Detail


Project/Job:


246313



Assumed ground bearing capacity of 250 kPa.

Minimum footing size (N =71.8 kN) Afooting = 71.8kN/250kPa = 0.287 m2

Footing size a = b = 600mm


Project/Job:


246313


Since each portal frame along gridlines 1, 2, 7 and 8 can resist 120kN each then central block portal frames must resist the

following shortfall lateral loads:

Total lateral load resistance from central blocks PFEnd_block_cap = 120kN 4 = 480 kN

From page 143, total demand PFload = 609 kN

Shortfall demand for central block portal frames SFcentral_block = PFload - PFEnd_block_cap = 129 kN

Demand per portal frame (4 total) in central block Fcentral_block_portal = SFcentral_block /4 = 32.3 kN

Portal frames along gridlines 3 and 6 are designed separately as these will support floor loads as well as lateral loads due to removal of existing timber walls. Account for accidental eccentricity of 0.1b (b is the horizontal plan length perpendicular to load application) as per NZS1170.5 for loads into portal frames along gridlines 3, 4, 5 and 6. Torsional loads will result from the accidental eccentricity and increase shortfall demands on portal frames.

b = 38.4m

0.1b = 3.84m

Central of mass is assumed to be at the very centre of the central block. All central block portal frames are to have similar member sizes and hence same stiffness is assumed for all frames. Distance from 0.1b to each central block portal frame is shown below:


Project/Job:


246313


r – Distance perpendicular to 0.1b location from centre of mass. Distribute lateral loads into portal frames based on stiffness and horizontal distance from 0.1b.

r1 = 7.1m

r2 = 0.3m

r3 = 7.6m

r4 = 14.9m

Following equations are used to determine torsional loads. Torsional moment results from shortfall loads multiplied by 0.1b. All central block portal frames has the same stiffness, k

k1 r12 = 50.4k

k2 r22 = 0.09k

k3 r32 = 57.8k

k4 r42 = 222k

ki ri2 = 330k

Torsional moments:

Mtroof = 3.84m x 173kN (from page 142)

= 664 kNm

Mtlevel1 = 3.84m x 129kN (from page 155)

= 495 kNm


Project/Job:


246313


Lateral loads into portal frames:

F1roof = (k x 7.1m/330k) x 664kNm

= 14.3kN

F1level1 = (k x 7.1m/330k) x 495kNm

= 10.7kN

F2roof = 0.6kN

F2level1 = 0.45kN

F3roof = 15.3kN

F3level1 = 11.4kN

F4roof = 30kN

F4level1 = 22.4kN

Critical demands for portal frames along gridlines 4 and 5 result from shortfall demands and torsional load from frame 3 above:

F4, 5 roof = 15.3kN + 43.3kN

= 58.6kN

F4, 5 level1 = 11.4kN + 32.3kN

= 43.7kN

Critical demands for portal frames along gridlines 3 and 6 result from shortfall demands and torsional load from frame 4 above:

F3, 6 roof = 30kN + 43.3kN

= 73.3kN

F3, 6 level1 = 22.4kN + 32.3kN

= 54.7kN


Project/Job:


246313


11.1 Central Block Strengthening

Design two-storey portal frames to be along gridlines 3, 4, 5 and 6. Portal Frame Height = 7.35m

Portal Frame Span = 7.2m

Portal frames along gridlines 3 and 6 must support first floor loads due to removal of existing walls. The

design of these portals will be done separately from portal frames along gridlines 4 and 5 which resist lateral

loads only.

Portal Frame Gridlines 4 and 5

Ultimate Limit State (G+0.4Q+E)


Project/Job:


246313





Project/Job:


246313


Lateral Inter-Storey Deflection Limit

ULS:


dmax = 2.5% 4.15m = 103.75mm for ground storey





Maximum inter-storey deflection occurs for the ground storey, 41mm < dfmax = 69.2mm. Okay


Project/Job:


246313


SLS:

Limit side sway of columns to height/500. Ground storey has critical displacements.

Ground storey displacement = 4.72mm < allowable sway = 4150/500 = 8.3mm. Okay


Project/Job:


246313


MemDes Calculations for Critical Portal Frame Column (Member 5)

Section : 460UB67 Grade 300+

d = 454 mm b = 190 mm tf = 12.7 mm tw = 8.5 mm



Eff. Len Le = 4.15 * 1.05 * 1.00 * 1.00 = 4.34m

Major Axis Bending



am = 1.7 * 213.0 / [( 160.0)2 + ( 106.0)2 + ( 53.0)2 ]0.5 = 1.819


Mo = 407.0 kNm ( Eqtn 5.6.1.1(4) )

as = 0.57




= 0.53, ---- OK ----





Vu = Vw = 740.9 kN


= 0.08, ---- OK ----

Axial Calculations



= 2442.5 kN


acx < 1.0 => Ncx = acx Ns = 2357.5


acy < 1.0 => Ncy = acy Ns = 1203.1



= 0.087, ---- OK ----


Project/Job:


246313





======================== SUMMARY =====================


============================================================

Project : Nelson Two Storey Block

Description : Critical Portal Frame Beam


d = 454 mm b = 190 mm tf = 12.7 mm tw = 8.5 mm



Eff. Len Le = 7.20 * 1.00 * 1.00 * 1.00 = 7.20m

Major Axis Bending



am = 1.7 * 243.0 / [( 119.0)2 + ( -2.0)2 + (-122.0)2 ]0.5 = 2.424


Mo = 181.0 kNm ( Eqtn 5.6.1.1(4) )

as = 0.33


Mbx = 2.42 * 0.33 * 444.0 = 355.0


= 0.76, ---- OK ----





Vu = Vw = 740.9 kN


= 0.10, ---- OK ----

Axial Calculations



= 2442.5 kN


acx < 1.0 => Ncx = acx Ns = 2196.8



Project/Job:


246313


acy < 1.0 => Ncy = acy Ns = 488.7



= 0.048, ---- OK ----


Significant Axial Load test (Cl. 8.1.4(a)) NOT Satisfied **** NOK ****

Significant Axial Load test (Cl. 8.1.4(b) IS Satisfied ---- OK ----


======================== SUMMARY =====================


============================================================

MemDes Calculations for Portal Frame Beam (Member 3)

Project : Nelson Two Storey Block

Description : 2nd Level Portal Frame Beam


d = 307 mm b = 166 mm tf = 11.8 mm tw = 6.7 mm



Eff. Len Le = 7.20 * 1.00 * 1.00 * 1.00 = 7.20m

Major Axis Bending



am = 1.7 * 67.0 / [( 31.0)2 + ( -2.0)2 + ( -34.0)2 ]0.5 = 2.473


Mo = 96.2 kNm ( Eqtn 5.6.1.1(4) )

as = 0.35


Mbx = 2.47 * 0.35 * 218.7 = 189.8


= 0.39, ---- OK ----





Vu = Vw = 394.9 kN


= 0.06, ---- OK ----


Project/Job:


246313


Axial Calculations



= 1802.9 kN


acx < 1.0 => Ncx = acx Ns = 1446.9


acy < 1.0 => Ncy = acy Ns = 307.4



= 0.110, ---- OK ----



Significant Axial Load test (Cl. 8.1.4(b) NOT Satisfied **** NOK ****


Major axis : Flg : Actual = 7.4, Allowable = 10

Web : Actual = 47.9, Allowable = 82 ---- OK ----

Minor axis : Flg : Actual = 7.4, Allowable = 10


Alt. Prov. Cl 8.1.5 (a)-(c) OK for Minor axis, OK for Major axis actions

Clause 8.3.2/4 :

Mrx = Msx (1 - N* / f Ns) * 1.18, =< Msx [Alt. Prov. OK]

= 218.7

Clause 8.3.3/4 :

Mry = Msy (1 - (N*/ f Ns)2 ) * 1.19, =< Msy [Alt. Prov. OK]

= 48.9


x)

= 0.34, ---- OK ----


= 213.6

>> Note : A bm value would enable the more economical Alt. Prov. to be used <<


= 0.349 ---- OK ----

Clause 8.4.4.1 : bmox = 0.95

1 / abc = (0.5 - bm/2) + [0.5 + bm/2]3 * (0.4 - 0.23 * N* / f / Ncy)

abc = 2.68

Noz = [G * J + ( p2 * E * Iw / Lz2) ] / [(Ix + Iy) / A ]


Project/Job:


246313


= 1432.25

Mbxo = Mbx / am = 189.8 / 2.473 = 76.7

Mox = abc * Mbxo * [ (1 - N* / f / Ncy) * (1 - N* / f / Noz) ]0.5 <= Mrx

= 192.04


= 0.388, ---- OK ----

======================== SUMMARY =====================


============================================================


Project/Job:


246313


Portal Frame Gridlines 3 and 6

Existing walls along gridlines 3 and 6 are to be removed. Floor loads will need to be supported by these new

portal frames. Summary of loads are shown in the table below. Critical load case is G+0.4Q+E. Applied

loads are shown below.

Ultimate Limit State (G+0.4Q+E)


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Lateral Inter-Storey Deflection Limit

ULS:


dmax = 2.5% 4.15m = 103.75mm for ground storey





Maximum inter-storey deflection occurs for the ground storey, 41.4mm < dfmax = 69.2mm


Project/Job:


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SLS G+0.4Q+Es

Limit side sway of columns to height/500. Ground storey has critical displacements.

Ground storey displacement = 4.77mm < allowable sway = 4150/500 = 8.3mm. Okay


Project/Job:


246313


MemDes Calculations for Critical Portal Frame Column (Member 5)


d = 460 mm b = 191 mm tf = 16.0 mm tw = 9.9 mm

Area =10500 mm2 fyf = 300 MPa fyw = 320 MPa fu = 440 MPa


Eff. Len Le = 4.15 * 1.06 * 1.00 * 1.00 = 4.39m

Major Axis Bending



am = 1.7 * 276.0 / [( 207.0)2 + ( 138.0)2 + ( 69.0)2 ]0.5 = 1.817


Mo = 545.3 kNm ( Eqtn 5.6.1.1(4) )

as = 0.60




= 0.56, ---- OK ----





Vu = Vw = 874.4 kN


= 0.08, ---- OK ----

Axial Calculations



= 3169.8 kN


acx < 1.0 => Ncx = acx Ns = 3054.6


acy < 1.0 => Ncy = acy Ns = 1550.0



= 0.098, ---- OK ----


Project/Job:


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======================== SUMMARY =====================


============================================================

MemDes Calculations for Critical Portal Frame Beam (Member 6)


d = 460 mm b = 191 mm tf = 16.0 mm tw = 9.9 mm

Area =10500 mm2 fyf = 300 MPa fyw = 320 MPa fu = 440 MPa


Eff. Len Le = 7.20 * 1.00 * 1.00 * 1.00 = 7.20m

Major Axis Bending



am = 1.7 * 333.0 / [( 131.0)2 + ( -24.0)2 + (-178.0)2 ]0.5 = 2.500


Mo = 258.4 kNm ( Eqtn 5.6.1.1(4) )

as = 0.37


Mbx = 2.50 * 0.37 * 552.0 = 508.3


= 0.73, ---- OK ----





Vu = Vw = 874.4 kN


= 0.14, ---- OK ----

Axial Calculations



= 3169.8 kN


acx < 1.0 => Ncx = acx Ns = 2840.6


Project/Job:


246313



acy < 1.0 => Ncy = acy Ns = 628.1



= 0.044, ---- OK ----



Significant Axial Load test (Cl. 8.1.4(b) IS Satisfied ---- OK ----


======================== SUMMARY =====================


============================================================

MemDes Calculations for Portal Frame Beam (Member 3)


d = 307 mm b = 166 mm tf = 11.8 mm tw = 6.7 mm



Eff. Len Le = 7.20 * 1.00 * 1.00 * 1.00 = 7.20m

Major Axis Bending



am = 1.7 * 75.1 / [( 34.0)2 + ( -2.0)2 + ( -39.0)2 ]0.5 = 2.466


Mo = 96.2 kNm ( Eqtn 5.6.1.1(4) )

as = 0.35


Mbx = 2.47 * 0.35 * 218.7 = 189.2


= 0.44, ---- OK ----





Vu = Vw = 394.9 kN


= 0.06, ---- OK ----


Project/Job:


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Axial Calculations



= 1802.9 kN


acx < 1.0 => Ncx = acx Ns = 1446.9


acy < 1.0 => Ncy = acy Ns = 307.4



= 0.150, ---- OK ----



Significant Axial Load test (Cl. 8.1.4(b) NOT Satisfied **** NOK ****


Major axis : Flg : Actual = 7.4, Allowable = 10


Minor axis : Flg : Actual = 7.4, Allowable = 10


Alt. Prov. Cl 8.1.5 (a)-(c) OK for Minor axis, OK for Major axis actions

Clause 8.3.2/4 :

Mrx = Msx (1 - N* / f Ns) * 1.18, =< Msx [Alt. Prov. OK]

= 218.7

Clause 8.3.3/4 :

Mry = Msy (1 - (N*/ f Ns)2 ) * 1.19, =< Msy [Alt. Prov. OK]

= 48.9


x)

= 0.38, ---- OK ----


= 211.7

>> Note : A bm value would enable the more economical Alt. Prov. to be used <<


= 0.394 ---- OK ----

Clause 8.4.4.1 : bmox = 0.93

1 / abc = (0.5 - bm/2) + [0.5 + bm/2]3 * (0.4 - 0.23 * N* / f / Ncy)

abc = 2.75

Noz = [G * J + ( p2 * E * Iw / Lz2) ] / [(Ix + Iy) / A ]


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= 1432.25

Mbxo = Mbx / am = 189.2 / 2.466 = 76.7

Mox = abc * Mbxo * [ (1 - N* / f / Ncy) * (1 - N* / f / Noz) ]0.5 <= Mrx

= 191.46


= 0.436, ---- OK ----

======================== SUMMARY =====================


============================================================


Project/Job:


246313



First Floor and Roof Portal Frame Connection

Connect 460UB82 to existing laminated timber beam for first floor connection detail. Thickness of laminated beam

is 240mm. Use timber blocking with M12 coach bolts to connect UB. Connect UB to existing timber trusses for roof

connection detail.

Critical first floor shear demand Qtot = 54.7kN

Critical roof shear demand Qtot = 73.3kN

Must transfer vertical shear of 5.55kN/m from floor loads for portal frames 3 and 6.

Coach Bolts


Shear Capacity parallel to the grain Qn = k1k12k13kQsk NZS 3603:1993-Section 4.5.2


k12 = 1.0 (Table 4.14, dry)

k13 = 1.0 (Table 4.15)

k = (90mm/(712mm)) = 1 (For 12mm Diameter bolt)

Qsk = 10.4kN (Table 4.10, maximum 2b =130mm)

Hence Qn = 0.7 k1k12k13kQsk =7.3kNTotal capacity of bolts with 400crs

Qntotal = (7200/400) x 7.3kN =131kN

Shear Capacity perpendicular to the grain Qn = k1k12k13kQsk NZS 3603:1993-Section 4.5.2


k12 = 1.0 (Table 4.14, dry)

k13 = 1.0 (Table 4.15)

k = (90mm/(712mm)) = 1 (For 12mm Diameter Bolt)

Qsk = 7.99 kN (Table 4.10, maximum 2b =180mm)

Hence Qn = 0.7 k1k12k13kQsk = 5.6kN

Total vertical shear demands from floor loads = 5.55kN/m x 7.2m = 40kN

Total capacity of bolts with 400crs Qntotal = (7200/400) x 5.6kN =100.8kN (perpendicular to the grain)


Project/Job:


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For first floor connection detail use M12 coach bolts at 400crs staggered pitch. This is sufficient to support vertical and

horizontal shear loads. Use M12 coach bolts at 400crs to connect UB at roof level to existing timber truss. Details are shown

below:

First Floor Connection

Roof Connection


Project/Job:


246313


Portal Frame Baseplate

Design baseplate to have 4-M20 EPCON C6 ANCHORS. Critical demands are tension and shear from page

168.

V* (shear) = 66.5kN

V* (per anchor) = 16.6kN

T* (tension) = 76kN

T* (per anchor) = 19kN

From spreadsheet calculation provided a minimum concrete edge distance of 170mm and 200mm embedment.


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Project/Job:


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Sizing Baseplate

Net tension results in bending of the plate. Must size plate based on flexural and shear strengths. Column flanges provide

pin restraints for bending. Analyse baseplate similar to beam bending with two point loads along a row of bolts in tension.

Web of column restrains baseplate in half.

M* = 16.6kN (tension per anchor) x 0.150m (lever arm)

= 2.49kNm

Try 20mm Grade 300 plate

M = fyZ

= 0.9 x 300MPa x (260mm x 20mm2)/6

= 4.68kNm > M*, OK

From calculation of shear strength below, 20mm baseplate suffices. Use 6mm FWAR to connect column to baseplate.


Project/Job:


246313



New foundations are required under each portal frame. Size dimensions based on 900mm depth and

maximum compression and tension loads.

V* (shear) = 66.5kN

T* (tension) = 76kN

From page 168 maximum compression is,

N* (compression) = 137kN

Assumed ground bearing capacity of 250 kPa. Check sizing under bearing loads:

Minimum footing size (N = 137 kN) Afooting = 137kN/250kPa = 0.55 m2

Sizing foundation based on net tension uplift:

Weight of first floor loads are already accounted for in G+0.4Q+E load case. Tie new foundation to existing foundation wall.

Engage 1m width of foundation wall either side. Must provide sufficient hold down capacity for foundation based on weight.


Project/Job:


246313


Dimensions of perimeter foundation walls:

Engaging 1m length of wall either side of new foundation:

Weight of wall = 24kN/m3 x 2m x 0.15m x 0.820m

= 5.9kN

Required foundation area using 900m depth. Use safety factor of 0.9

76kN/0.9 < 5.9kN + 24kN/m3 x (0.9m x Area)

Area > 3.6m2

Use 2.15x2.15x0.9m pad foundation under each portal frame column in the central block.

Tie new foundations into existing perimeter wall using H12 bars at 300 centres with 400mm embedment:

Load is transferred through shear friction. Conservatively assume axial load contribution as 0.

= 0.7 – concrete anchored by reinforcing bars

Vn = 0.85 x x (12)2 /4 x 500MPa x 0.7

= 33.6kN per bar. Use 400crs


Project/Job:


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Foundation Reinforcement:

From spreadsheet below use 8H20 U bars each way top and bottom. Bending moment demands for footing are low due to

large size. Reinforcement design is governed by minimum reinforcing steel requirements as per NZS3101.


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Final Bracing Configuration for Option 2


Project/Job:


246313


12. Foundations

The foundation system consists of a series of reinforced concrete foundation walls around the perimeter of

the structure and underneath seismic bracing elements. A series of square concrete piles are also well

distributed throughout the structure in between the foundation walls.

It was found that the timber tongue and groove floor diaphragm can transfer seismic load to the foundation

walls, the square concrete piles are not required to resist seismic loading.

By inspection, the foundation walls are expected to perform satisfactorily as uplift/overturning was found to

be resisted in the walls of the End Blocks. This will limit the bearing pressure acting on the foundation walls.

By inspection, the bracing walls in the Central Segment will be satisfactory also due to their relatively high

length to height aspect ratios and having the floor above to resist uplift forces.

When strengthening a specific Nelson Two Storey Block, it needs to be ensured that foundation walls exist

underneath all wall bracing lines.


Project/Job:


246313


13. Wall Hold-Downs

13.1 Proprietary Bracing Elements

The timber framed shear walls to be lined with proprietary Gib Braceline and Ecoply EP1 elements require Gib HandiBrac hold

down fittings, secured into the concrete slab by steel bolts with a minimum tension capacity of 15kN. These elements also

require that the hold down requirements of NZS3604:2011 are met elsewhere.

Gib HandiBrac Hold-Downs

12mm diameter Chemset Achoring Studs will provide the required hold down capacity and are easily installed in retrofit

applications.

Bottom Plate Fixing

Within the length of the bracing elements the bottom plate is to be fixed to the concrete slab or foundation in accordance with

the requirements of NZS3604. These requirements are that an M12 bolt, fitted with a 50x50x3mm washer, shall be within 150mm

of each end of the plate and spaced at a maximum of 900mm centres.

These criteria will ensure the proprietary Gib elements will achieve their specified capacities.

Gib HandiBrac Hold-Down Bracket

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