mid report rev 1

8/8/2019 Mid Report Rev 1

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Submitted By:Muhammad Daniyal (2007CV088)Sadiq Hammad (2007CV087)Irfan Rasheed (2007CV086)Azhar Irshad (2007CV090)Fawad Khalil (2007CV122)

Design of Dome of New Sindh Assembly Building .

Internal Advisor : Dr. S.M.MakhdomiProject Supervisor : Ms.Tatheer ZehraExternal Advisor : M. Rizwan Gul

Sir Syed University of Engineering and TechnologyDepartment of Civil Engineering


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IndexS.No. Contents Page No.

1 Introduction 1

2 Background 3

3 Design Theory 5

4 Modeling 7

5 Analysis 10

6 Design 13

7 Appendix A : Manual Design Calculation

8 Appendix B : Design Code

9 Appendix C : Architectural Drawings


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1. Introduction

1.1 . Project Title:

Design of Dome of new Sindh Assembly Building .

1.2. Introduction of Project:

The new structure of Sindh Assembly Building is being raised in the backyard of the existing historic assembly building at an estimated cost of over Rs. 1.9 Billion and the completion time is 30 months President Asif Ali Zardari performed the ground breaking ceremony of the new Sindh Assembly Building on August 15, 2009. The state of the art project comprising of ground plus three stories, besides the hall, with one chambers each for the leader of the house and the leader of the opposition, rooms for ministers, an auditorium with capacity of 350 audience, a library, a mosque and a cafeteria.

The existing building would be linked with the new one through two corridors and would be preserved as a heritage building as the historic Pakistan Resolution was passed in the same building. Moreover, the declaration of independence was made and the flag of Pakistan was unfurled for the first time in Sindh at the same place.

The plan of New Building was approved as a result of Design Competition held by a committee and the contract was awarded to Architect M/s Naqvi and Siddiqui Associates and M/s Akbar

and Associates were selected as the Structural Engineers. The Architects planned a dome as key architectural feature over the assembly hall. Dome itself is a very stable structure and enhances the architectural value of the building as well as enhances the aesthetics of the interior. Structural Designing of Dome is a complex process involving the use of Advance Structural Analysis and Design Software. The main purpose of selecting this project is to understand and learn the design procedure of complex shell structures after the completion of project we will be able to design and study behavior of different shell structures.

1.3. Goal of Project:

To learn the design procedure of Spherical Domes.

1.4. Objectives: Analysis and Design of Dome of new Sindh Assembly Building.

Analysis and Design of Supporting Trusses of the Dome.


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1.5. Procedure and Design Philosophy: Understanding the Architecture Layout.

Calculation of Loads. Analysis and Design of Dome in SAP 2000.

Calculation of support Reaction of Trusses.

Analysis and Design of Trusses in ETAB

1.6. Required Resources: Structural Analysis and Design Software SAP 2000.

Structural Analysis and Design Software ETABS.


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2. Background

2.1. History of Dome: Throughout history, the dome has been the architectural form of choice wherever efficiency and strength are required of a structure. From the simple igloo that shelters the Arctic hunter through the ravages of a blinding storm, to the awe inspiring magnificence of the Sistine Chapel, the dome has been used in every culture, on every continent, as one of man's most versatile constructions.

Today, modern construction techniques and materials reinforce the dome's position as the most classically versatile of all structures. The insulated concrete dome is the ideal solution wherever strength combined with low construction costs are called for. Compared to other

types of

structures,

the

domes

enclose

more

volume

with

the

greatest

floor

area,

and

the

least

amount of surface area and perimeter. Superbly energy efficient, fire safe, and with an inherent strength that enables it to withstand whatever nature throws at it, hurricanes, earthquakes, even tornadoes. It's no wonder that the modern concrete dome is experiencing a surge of popularity throughout the world.

2.2. Dome Construction Process:

Many memorable structures throughout history, like the Pantheon, have been built using the thin shell hemispherical shape of the dome. These time tested monuments surpass many in

beauty

and

longevity.

Continuing

in

the

tradition

of

these

magnificent

edifices,

Dome

Technology engages the latest engineering and architectural technologies to produce aesthetic, functional, and economical schools, gymnasiums, water parks, community centers, and industrial facilities. At a fraction of the cost of a conventional structure, each building benefits from unobstructed views, seating efficiency, great acoustics, and space utilization.

Modern insulated concrete dome construction combines several materials to create a strong, efficient, weather proof structure. Compared to other types of structures for the same application. The Dome is rested upon ring Beam. Continuous reinforcing bars are embedded in the ring beam foundation. These rebar dowels securely connect the dome to its footing. The ring beam creates a solid base on which to construct the dome.

The dome structure then itself is raised upon this beam laying the reinforcement mesh then covering it up with concrete and shotcrete.


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2.3. Benefits and Advantages:

The concrete dome's free span construction imparts the ultimate flexibility for architectural design. It is ideally suited for large scale structures such as auditoriums, schools, athletic facilities, arenas, stadiums, gym or gymnasiums, convention halls, churches, stores, shops, and warehouses, including freezer operations.

Domes offer an exceptional alternative to conventional square design. The customer has complete freedom in the size and layout of the rooms, and number of openings. Construction is quick regardless of weather.

Insulated concrete domes offer superb energy efficiency. Heating and cooling a dome typically costs 1/4 to 1/2 less than a conventional building the same size. This cost savings has to do with how the dome is constructed.

Most of the materials used to construct a dome are non flammable and safe enough in some architectural structures to be approved for construction without the installation of a fire sprinkler system. Low maintenance is also a quality of a Monolithic Dome. Snow and water inflict relatively little stress on the exterior of a dome since its' shape sheds water quickly. Leaks are rare compared to conventional dome structures and are easily repaired.

Because of the Monolithic Dome's inherent strength, they are able to withstand the forces of nature with no structural damage. A Monolithic Dome is easily able to withstand winds of 150

MPH, as it allows winds to pass around it, eliminating serious pressure build up. Most conventional structures are unable to endure the forces of a hurricane or tornado. The

Monolithic dome has proven its strength and durability. Where seismic events are a concern, domes are a choice to be recognized. These safe and durable structures are a good choice for

all types of architectural needs.


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3. Design Theory

3.1. Dome as a Shell Structure: Dome is considered as a shell structure and its analysis and design is based on Shell Theory but modern Analysis and Design Software design the dome as a shell structure using Finite Element Method in which whole area is divided into smaller section which are then analyzed and design accordingly.

The major stress and forces acting on a dome for which it is designed are as follows.

3.1.1. Edge Disturbances:

The Reactive force which are present at the edge of shell which is connected to some rigid support, such as a ring beam, set up stresses in to the shell body. The upward penetration and distribution of these forces follows the pattern of dampening waves i.e., the intensity or wave amplitude is greatest at the shell edge and vanishes in propagation as damped waves. This distribution is termed as edge disturbance.

3.1.2. Membrane Stresses:

If the shell is idealized as a membrane incapable of resisting bending moments the stresses thus computed are called membrane stresses.

3.1.3. Bending Stresses:

The stress resultants, computed under the assumption that shell body is capable of developing

resisting moments

and

hence

the

transverse

share

are

classed

bending

stresses.

[1]

3.2. Design code:

The American Concrete Institute Code ACI2002 will govern all the design procedures, limiting values and load cases in the design and analysis of said Structure.

3.3. Loads:

The following Loads are considered on Shell.

Outer Finishes + Water Proofing = 30 psf.

Inner Finishes = 15 psf.

Point Load on Crown = 1 Ton.

Live Load = 15 psf

[1] Paper on Economical Design of Masjid Dome by Shiekh Waleed, Bakhtyar Ali and Muhammad Azim.


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3.4. Dimensions: Height of Dome = 24

Clear Span = 64

Shell Thickness = 4

3.5. Design Work Flow:

Calculation of Loads on Shell

Calculating Self

Weight

of

Structure

Modeling of Dome

Assigning Member Properties

Assigning Loads

Analyzing the Model

Verification of Model from results of Manual Calculations

Determination of Support Reaction

Designing of Shell


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4. Modeling

4.1. Calculation of Self Weight of Structure: Calculation of Self Weight of Structure is done for the Verification of Modeling Process. The results are as follows.

Self Weight of Dome = 246.72 Kips

Self Weight of Ring Beam = 242.50 Kips

Total Live Load = 77.138 Kips

Total Dead Load = 233.65 Kips

Ultimate Load = 990 K [2]

4.2. Modeling of Dome in SAP 2000:

To begin our model we use the basic templates present in SAP 2000 from where we select Shell then Partial Dome. SAP asks four major things to make our model using wizard.

Radius, R

Role down Angle, T

Number of Divisions Angular

Number of Divisions, Z.

For our case we put the following values.

Radius = 386 in.

Roll Down Angle = 73.83 o [2]


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Number of Angular Divisions = 24

Number of Divisions, Z = 10

As a result of which SAP 2000 make us our desired model.

4.3. Assigning Joint Restrains:

The said structure is supported on 8 points which are selected and joint restrains are applied on them using Assign > Joints > Restraints. in such a way to make them Pin Support.

4.4. Defining Material Properties:

The concrete of 3000 psi cylindrical strength is used in the structure so it is defined using Define > Materials > Add New Material.

4.5. Defining Sections:

The Beam Section is defined using Define > Section Properties > Frame Sections.. and the Section of Shell is defined using Define > Section Properties > Area Sections.

4.6. Defining Load Patterns and Load Combinations:

The load patterns and combinations are defined using Define > Load Patterns and Define > Load Combinations. Here the ACI 2002 Code Governs the Load Combination i.e 1.2 Dead + 1.6 Live.

4.7. Drawing Ring Beam:

The Draw > Draw Frame/Cable/Tendon option is selected and then ring beam is drawn passing all the joints using the B24X48 section previously defined.

4.8. Assigning of Shell Section:

All the plate members are selected and the perivously defined Area Section S4 is assigned usind

Assign > Area > Sections.

[2] Appendix A (Manual Calculations).


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4.9. Assigning Loads:

Three types of Loads are applied to the model.

Super Imposed Dead Load of 45 psf. Which includes load of Outer finishes and Water Proofing

= 30 psf and Inner finishes = 15 psf. Live Load of 15 psf

Super Imposed Dead Load at Crown of 2.24 Kips which is equal to 1 Ton.

All loads are applied selecting appropiate sections then going to Assign > Area Loads or Assign > Joint Load .

4.10. Finishing the Model:

Our Model is now complete which is shown in figure the next step is to Analyze the model.


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5. Analysis

5.1. Analyzing the Model: To analyze the model goto Analyze > Run Analysis

5.2. Verification of Model:

In order to verify the model we can compare the reactions given by SAP 2000 with our manual calculations. If we have model rightly then Sum of all reaction forces will be equal to the total load we had calculated manually.

The Total Load which comes out of our manual calculations shown in Appendix A is equal to 990

Kips. The Reaction Forces given by SAP 2000 are as follows:

Support F1 (Kips.) F2(Kips.) F3(Kips.)

1 14.54 14.54 98.95

2 0.00 20.57 98.95

3 14.54 14.54 98.95

4 20.57 0.00 98.95

5

14.54

14.54

98.95

6 0.00 20.57 98.95

7 14.54 14.54 98.95

8 20.57 0.00 98.95

The Summation of all Reaction Forces = 990.2 Kips which is nearly equal to our calculated value of 990 kips hence the model will be considered correct.


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Distribution of F Max in pounds per square inch.

Distribution of M Max in pounds.inch


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The following figure shows the distribution of S Max in pounds per square inch.


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6. Design

6.1. Design of Dome: Shell can be designed by going to Design > Conc. Frame Design > Start Design / Check of structure as a result of which SAP 2000 gives us area of steel in ring beam and shell.

SAP 2000 gives us two are of steel for shell. One is Area of steel in X direction that is ASt 1 and the second is area of steel in Y direction that is ASt 2.

The Following diagram show distribution of ASt1 in inches.

The Following diagram show distribution of ASt2 in inches.


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N.B : We have completed the design process until the viewing of Area of Steel from Softwares diagrams. Further discussion regarding the governing area of steel and its placement will be discussed later on.

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