safety report of 6 storied canteen building dird

Design Project 6 STORIED CANTEEN BUILDING FOR DIPTA GARMENTS LTD. Doc. No. TCS.DGL-01Consultant THE CIVIL AND STRUCTURES Rev. 01Title REPORT ON SAFETY OF SIX STORIED CANTEEN

BUILDING-3 FOR DIPTA GARMENTS LTD. AT SA 136, 137 & 138 MOUZA NAGARCHAR, SAVAR, DHAKA

Date 25.03.2014

ANALYTICAL REPORT ON SAFETY OF SIX STORIED CANTEEN BUILDING FOR DIPTA

GARMENTS LTD. AT SA 136, 137 & 138 MOUZA NAGARCHAR, SAVAR, DHAKA

Revision History

0 Revision-0 (Original Issue ID:TCS.ST-01) 25-03-2014

Rev. Revision information Date

Reviewed by Approved by

Mostafizur Rahman Mohammad Mahfuzur Rahman

Owner: TCS of 16



Date 25.03.2014

Owner: TCS of 16



Date 25.03.2014

Table of Contents

1.0 INTRODUCTION2.0 SCOPE OF WORK3.0 VISUAL INSPECTION 4.0 ANALYTICAL STUDY5.0 STRUCTURAL DESIGN CONCEPT & CRITERIA.

5.1 CODES AND STANDARD5.2 LOADS CONSIDERED FOR EACH FLOOR5.3 MATERIALS CONSIDERED IN DESIGN 5.4 TOP DEFLECTION DUE TO LATERAL LOAD5.5 SOIL INVESTIGATION REPORT5.6 ADEQUACY OF FOUNDATION5.7 ADEQUACY OF COLUMN5.8 ADEQUACY OF SLAB AND BEAM DESIGN

6.0 CONCLUDING REMARKS

APPENDIX A SOIL INVESTIGATION REPORTAPPENDIX B AS BUILT ARCHITECTURAL DRAWINGSAPPENDIX C AS BUILT STRUCTURAL DRAWINGS

Owner: TCS of 16



Date 25.03.2014

1.0 INTRODUCTION

The proposed six storied canteen building for DIPTA Garments Ltd. is located on plot No SA 136, 137 & 138, Mouza- Nagarchar, Savar, Dhaka. The structure is designed by S M Wahiduzzaman, BSc Engineer, Civil, FIEB- 6851 and Eng Md. Masud Rana. The factory building is approved by Deputy Chief Inspector(General), Department of Inspection Factory and Establishment, Dhaka Division by the letter No : 4389 dated 27-6-2013. The building is 60 ft long and 40ft wide supported on 14 columns. The floor system is two-way slab on beams. The structural system is moment resisting frame. The building is on individual footing and combined footing for some columns. The ground floor is used for worker canteen, doctor’s room and day care center. The first floor is for worker canteen. The 2nd, 3rd and 4th floor is sewing area. The 5th floor is for dining.

2.0 SCOPE OF WORK

The scope of work is to evaluate the structural and foundation adequacy of the building based on the as-built architectural and structural drawings. The safety assessment of the building for maximum loading combinations that it is likely to experience during its lifetime requires comprehensive investigation involving detailed structural analysis based on design strength. Checking of different structural members will be done on the basis of actual strength of concrete and steel used in construction.

The major scope of the work is to check the safety and stability of different structural members, like

a) Checking for the top deflection of the structure b) Adequacy of the individual footingsc) Adequacy of the column sizes and reinforcement.d) Checking the design of other structural members.

3.0 VISUAL INSPECTION

The Consultants visited all floors of the building and inspected the physical condition of both structural members (columns, beams, floor slabs etc.) and non-structural members (brick partition walls (etc). No visible cracks are found in any place of the buildings.

From the visual inspection of the building it appears to be safe. There is no likelihood of any threat or risk in using the building for the purpose intended.

Owner: TCS of 16



Date 25.03.2014

4.0 ANALYTICAL STUDY

Based on the supplied as built architectural and structural drawings, The Consultant “The Civil and Structures” (TCS) independently developed a computer analysis model and carried out complete analysis of the structure incorporating various design requirements as per Bangladesh National Building Code (BNBC). Loading values, load combinations, design parameters, strength calculation are taken from the BNBC and design parameters used in the design drawings. The results obtained from computer model are checked against relevant specifications and hand calculations. Finally, based on the analytical results, structural and foundation safety and stability are recommended.

5.0 STRUCTURAL DESIGN CONCEPT & CRITERIA

The structural element of the complex has been designed considering the following criteria.

5.1 CODES AND STANDARD

Bangladesh national Building Code - 1993 (BNBC)American Concrete Institute (ACI 318-99)American Society for Testing Materials (ASTM)

5.2 LOADS CONSIDERED FOR EACH FLOOR

Dead load:

Dead load is the vertical load due to the weight of permanent structural and non-structural component of a building, e.g walls, ceilings, permanent partitions and fixed service equipment. Unit weight of materials and the calculation of design dead loads are according to section 2.2, Chapter 2, part 6 of BNBC.

Live load:

Live load is the load superimposed by the user or occupancy of the building but not including the environment load. The live load considered for the building is given below in Table 1:

Owner: TCS of 16



Date 25.03.2014

Table 1: Floor occupancy and live load

Serial Floor Use of floor Height ofFloor (ft)

Live load(psf)

1 Ground floor Worker canteen, Doctors room and day care center

14 80

2 1st Floor Worker canteen 12 603 2nd, 3rd & 4th

floorSewing area 12 40

4 5th floor Finish goods store, Dining 12 80

Wind load:

The calculation of wind load conforms the Sub-clause 2.4, Chapter 2, and part 6 of BNBC. The following equation has been used to calculate design wind pressure of the structure

Pz = Cg Cp Cc Ci Cz Vb2 [BNBC, 2.4.6.2, 2.4.6.3 page – 6-33, 6-34]

Exposure A was considered for wind load calculation.

Following are the basic parameters assumed for wind loads on building.

Basic Wind Speed: 215 Km/hr (Ref. BNBC)Structure Importance Coefficient: 1.0Exposure Category: ‘A’Combined Height and Exposure Coefficient: As per Table 6.2.10 (Ref. BNBC)

Overall pressure coefficients for wind load are used as per table 6.2.15 (BNBC)

Seismic load:

Owner: TCS of 16



Date 25.03.2014

The calculation of seismic load conforms the Sub-clause 2.5, Chapter 2, Part 6 of BNBC. Equivalent Static Force Method has been used for calculation of seismic lateral forces for the factory building.

Load Combination:

R.C. structural member will be designed to have strength not less than that required to resist the most unfavorable effect of the combination of the factored loads shown below.

1. 1.0DL + 1.0 LL2. 1.0 DL + 1.0 WL3. Ref: BNBC, Part 6, sec 2.7.5

However for foundation design following load combination will be considered1. DL + LL2. DL + LL + WL

Where DL = Dead load, LL = Live load, WL = Wind load.33 % overstressing allowed when DL + LL + WL load governs.

5.3 MATERIALS CONSIDERED IN DESIGN

Material strength considered Concrete:Compressive Strength of Concrete fc’ = 3,500 psi for columns upto 3rd floor slab and for columns above 3rd floor and for beams and slabs used fc’ = 3,000 psi, using brickchips.

Reinforcement: Deformed bar with minimum yield strength of 60,000 psi.

5.4 TOP DEFLECTION DUE TO LATERAL LOAD

The Top deflection of the building due to lateral load is given below. No infill wall is considered in the analysis. But due to the presence of partition infill walls, the deflection of the real structure will be less.

Owner: TCS of 16



Date 25.03.2014

Point UX UY1 0.629 0.0231 -0.075 0.7031 1.045 0.0521 -0.211 1.8282 0.635 0.0232 -0.037 0.7032 1.058 0.0522 -0.105 1.8283 0.642 0.0233 0.004 0.7033 1.073 0.0523 0.012 1.8284 0.655 0.0234 0.083 0.0834 1.102 1.1024 0.235 0.2355 0.629 0.015 -0.075 0.6225 1.045 0.0235 -0.211 1.6016 0.635 0.016 -0.037 0.6226 1.058 0.0236 -0.105 1.6017 0.642 0.017 0.004 0.6227 1.073 0.0237 0.012 1.6018 0.655 0.018 0.083 0.6228 1.102 0.0238 0.235 1.6019 0.629 -0.0039 -0.075 0.5429 1.045 -0.0079 -0.211 1.37510 0.635 -0.00310 -0.037 0.542

Owner: TCS of 16



Date 25.03.2014

10 1.058 -0.00710 -0.105 1.37511 0.642 -0.00311 0.004 0.54211 1.073 -0.00711 0.012 1.37512 0.655 -0.00512 0.083 0.54212 1.102 -0.00712 0.235 1.37513 0.629 -0.01613 -0.075 0.46113 1.045 -0.03613 -0.211 1.14814 0.635 -0.01614 -0.037 0.46114 1.058 -0.03614 -0.105 1.14815 0.642 -0.01615 0.004 0.46115 1.073 -0.03615 0.012 1.14816 0.655 -0.01616 0.083 0.46116 1.102 -0.03616 0.235 1.148

The corresponding unfactored deflection is 1.828 inch which is within allowable limit H/400 (i.e 63*12/400 = 1.89 in). Hence it is safe and stable from deflection point of view.

5.5 SOIL INVESTIGATION REPORT

The sub-soil exploration for the project of construction of Different buildings of DIPTA Garments was carried out by “Design Consultant Engineers & Boring” of House No-Ka/5/A, Bashundhara Road, 3rd Floor, Jagganathpur, Dhaka on January 2010. The program includes execution of total 3(Three) Nos. exploration boring upto a depth of 60 ft to 70 ft below from EGL. They recommended that the average bearing capacity (F.S=2.5) of the shallow foundation as isolated column footings may be considered 1.0 tsf at a depth of 10 ft measured from EGL. In November 2013, another sub-soil investigation work was done by Suchana Engineers Limited, 272/A West Agargaon, Modina Shaluk, Dhaka-1207. One Number borehole upto a depth of 15.0 m was carried

Owner: TCS of 16



Date 25.03.2014

out. Allowable bearing capacity recommended for isolated footing at a depth of 8.0 ft is 1.60 tsf. The actual foundation is provided at a depth of 8’-0” from EGL on a 2.0 ft compacted sand (F.M=1.0) mixing 5% cement thoroughly dry condition.

5.6 ADEQUACY OF FOUNDATION

The foundation of the factory building is on individual footings. The reinforcement provided is also found satisfactorily from flexural moment.

Figure: Footing layout plan

Name of Footing

Maximum Service Load from Column

(Kip)Footing Size

Effective soil pressure (ksf)

F1 159 8’X8’ 2.48F2 210 9’X9’ 2.59F3 271 10’X10’ 2.71F4 156 12’X5’ 2.6F5 Combined footing

Owner: TCS of 16



Date 25.03.2014

The soil pressure under the columns ranges from 2.48 ksf to 2.71 ksf which is within the allowable bearing capacity 3.5ksf of soil. The soil pressure from column load is within range of allowable soil pressure. So the provided footings can take the column loads coming from the 6 storied building.

Th grade beam 10” x 12” with 2 – 16mm rod at both top and bottom provided at just below the EGL with extra footing F6 and short column at the center of every span is sufficient to tie the whole building together. Besides 6” thick RCC ground floor slab at plinth level will be additional safety against bearing failure of the building. This ground floor RCC slab will also act as mat foundation.

5.7 ADEQUACY OF COLUMN

The reinforcement required at ground floor level for the columns is shown in the following table

Table 5: Column reinforcement

Column designation in drawing

Total Column Load (kip)

Column Grid No.

Provided reinforcement

(in2)

Required reinforcement

(in2)

C1 159 1A 5.76 4.7C1 271 2A 5.76 4.6C1 271 3A 5.76 4.0C1 158 4A 5.76 4.0C1 267 1B 5.76 4.81C2 468 2B 7.68 6.63C1 374 3B 5.76 6.37C1 210 4B 5.76 4.03C1 237 3C 5.76 5.48C1 151 4C 5.76 4.36C1 156 1D 5.76 4.7C1 265 2D 5.76 5.54C1 176 3D 5.76 4.51C1 99 4D 5.76 3.14

The reinforcement provided at ground floor levels are found adequate for most of the columns. Provided reinforcement in all columns at other floor levels are also found more than the required reinforcement. Hence all columns are safe.

Owner: TCS of 16



Date 25.03.2014

5.8 ADEQUACY OF SLAB AND BEAM DESIGN

The ground floor roof slab is two way beam supported slab. The maximum panel size is 19’-4” x 19’-0” and the thickness provided 5.5” is adequate as per BNBC / ACI Code. The reinforcement provided in ground floor roof slab is 12mm@5”c/c alt ckd in both short and long direction. 2- 12mm extra top is provided in interior support and 1-12mm extra top in exterior support. The reinforcement is more than adequate. Slab reinforcement is adequate to carry the load upon it. The floor beams provided are 12’ x 21” and the reinforcement provided is shown in Appendix-C. The beam reinforcement required from ETABS analysis is shown below.

Figure: Beam reinforcement (in2) in 1st floor of the building

Required reinforcement of beam is less than provided reinforcement. Hence beam size and reinforcement is safe.

Owner: TCS of 16



Date 25.03.2014

6.0 CONCLUDING REMARKS

The structure was modeled using 3-D computer program ETABS and designed for all possible load combinations. The following observations have been done.

The corresponding unfactored deflection is 1.828 inch which is within allowable limit H/400 (i.e 63*12/400 = 1.89 in). Hence it is safe and stable from deflection point of view.

The soil pressure under the columns ranges from 2.48 ksf to 2.71 ksf which is within the allowable bearing capacity 3.5ksf of soil. The soil pressure from column load is within range of allowable soil pressure. So the provided footings can take the column loads coming from the 6 storied building.

The column reinforcement provided at ground floor levels are found adequate for all columns. Provided reinforcement in all columns at other floor levels are also found more than the required reinforcement. Hence all columns are safe.

The ground floor roof slab is two way beam supported slab. The maximum panel size is 19’-4” x 19’-0” and the thickness provided 5.5” is adequate as per BNBC / ACI Code. The reinforcement provided in ground floor roof slab is 12mm@5”c/c alt ckd in both short and long direction. 2- 12mm extra top is provided in interior support and 1-12mm extra top in exterior support. The reinforcement is more than adequate. Slab reinforcement is adequate to carry the load upon it. The floor beams provided are 12’ x 21” and the reinforcement provided is shown in Appendix-C. The beam reinforcement required from ETABS analysis is shown below. Required reinforcement of beam is less than provided reinforcement. Hence beam size and reinforcement is safe.

.

Owner: TCS of 16



Date 25.03.2014

APPENDIX A

(SOIL INVESTIGATION REPORT)

Owner: TCS of 16



Date 25.03.2014

APPENDIX B

(AS BUILT ARCHITECTURAL DRAWINGS OF BUILDING)

Owner: TCS of 16



Date 25.03.2014

APPENDIX C

(AS BUILT STRUCTURAL DRAWINGS OF BUILDING)

Owner: TCS of 16

safety report of 6 storied canteen building dird

Documents

storied canteen building

factory building

structural members columns

structural system

structural drawings1

floor system

dipta garments

worker canteen