Project 2_Design & Analysis of a Hostel building at Guwahati, Assam

Project 2_Design & Analysis of a Hostel building at Guwahati, Assam

In this project, participants will get to experience the entire design process from modelling, analysis, design, and preparation of construction drawings. The architectural drawings of a G+3 RCC building is provided. The following information on the building is to be used:

• Location – Guwahati, Assam
• Function – Hostel block in an academic institute

The walls will be made of AAC blocks. Other loadings are to be calculated as per the architectural drawings.

The buildings rests on type 3 soil. Piles of length 10 meters and 500 mm diameter with a load-carrying capacity of 280 KN is to be used.

The ground floor level will be at a height of 2 meters above the existing site level to avoid floodwater enter the building.

M25 grade of concrete with Fe500 for longitudinal reinforcement and Fe 415 for shear reinforcement is to be used.

The following design IS codes will be required for reference:

• IS 875 part 1
• IS 875 part 2
• IS 13920
• IS 1893
• IS 2911 part 2
• IS 456
• SP 34

Students will have to produce the following:

• Etabs model for the two blocks on either side of the expansion gap
• Foundation details illustrating the pile & pile cap reinforcement
• Tie beam details connecting the pile caps
• Column reinforcement
• Framing plan for typical floor
• Beam reinforcements for ground floor

ANSWER:

AIM

• To design and analyse for a G+3 Hostel block in Guwahati, Assam in ETABS and also foundation details using SAFE.

INTRODUCTION

• ETABS is an engineering software product that caters to multi-story building analysis and design. Modeling tools and templates, code-based load prescriptions, analysis methods and solution techniques, all coordinate with the grid-like geometry unique to this class of structure.
• SAFE offers a single user interface to perform modeling, analysis, design and reporting. A new model explorer is available for quick access to objects, properties and forms. It is ideal for modeling foundations, basemats, and footings. Easily model soil supports and zero tension soil models with uplift analysis. The area assignment of soil supports is based on the subgrade modulus, and they automatically adjust whenever the mesh changes. Basemat foundation models can include pedestals, walls, columns, beams, and piles in addition to the foundation area.

DETAILS AND CALCULATIONS

Details Required for ETABS Analysis

• Pinned Support
• Base + 5 Story (Plinth to Roof) + 1 Mumty
• Column: 450x650, 650x650
• Beam: 400x550
• Slab :150mm thick
• No shear wall necessary
• Floor live load = 2 kN/m²
• Terrace live load = 1 kN/m²
• Floor finish + Ceiling finish =1 kN/m²
• Partition wall load = 3.5 kN/m
• Balcony wall load = 1 kN/m
• Guwahati seismic Zone-V

Details required for SAFE analysis & Design

• Column: 450x650, 650x650
• Pile Length = 16 m
• Pile diameter = 500 mm
• Load carrying capacity = 280 kN
• Soil Bearing Capacity 150 kN/m²

PROCEDURE

ETABS

Step:-1

• First we have to oprn the etabs software.
• Next click on the file option at the left side top corner and select the new model, as shown below.
• After selecting the new model the new tab opens, in that tab we have to select 'Use Built-in Settings with' option, as shown below.

• After setting the model Initialization the templates tab will opens and, select the Grid only and press ok.
• Next we need to do the settings in Grid system data, as shown below.

• Next we need to add the stories upto story in the Story Data, as shown below.
• Click 'Edit Story Data'
• Assign 'Story' and 'Height' as shown in this figure
• Assign '1F' as the 'Master Story'
• Assign '2F' and '3F Floor' as 'Similar To' '1F'
• Click 'OK'

Step:-2

• Next the plan views are visible in the etabs screen, as shown below.
• Next we need to open the 3d-view, as shown in the below figure.

Step:-3

• Next we need to open define option and select material properties, as shown below.

• New dialogue box will appear named Define Materials.
• Select Add new Material from the window.

Step:-4

• Now we need to add material type as concrete and grade as M25.
• Next we need to check the material property data, as shown below.

• Now we need to add new material type as rebar and grade as HYSD Grade 500.
• Next we need to check the material property data, as shown below.
• Now need to add material type as rebar and grade as HYSD 500.
• Now we need to check the material property data, as shown below.

• Hence the materials are assigned, as shown below

Step:-5

• Now we need to select the section properties and click on the frame sections, as shown below.

• After selecting the frame sections the new tab will be visible, in that we need to select the Add New Property, as shown below.

• After selecting the Add New Property, the new tab appears.
• In that new tab we select the Rectangular shape type in concrete, as shown belo
• Next the frame section property data will be visible, In that we add beam size as B450x650, as shown below.
• Next we need to select the Modify/Show Rebar option as shown below.
• After selecting the Modify/Show Rebar option the new tab appears, In that we select the design type as M3 Design only (Beam).
• Next we select longitudinal bars with the grade of HYSD500.
• Next we select Confinement bars with the grade of HYSD415.

Step:-6

• Next we have to add the column size as 450X650 in the frame section property data, as shown below.

• Create a new Property as a column and input values as 650*450
• Select Modify/Show Rebar in Reinforcement option.
• Select P-M2-M3 Design (Column).
• Select Reabar as HYSD415.

Step:-7

• Next we select the slab section option from the section properties, as shown below.

• Next the slab properties tab will be vissible, In that we select the Modify/Show Property option, as shown below.

• After selecting the Modify/Show Property option, the new tab appears.
• In that we need to put the slab name as Slab 125, it means slab with the thickness of 125mm.
• And we take the concrete grade as M25, as shown below.
• Next we have to click the ok option.

• Now we take the slab thickness separately for staircase with the thickness of 200mm, as shown below.

• Hence the Slab properties are assigned, as shown below

Step:-8

• Next we need to add the columns using the Quick draw columns option, as shown below.

• Now draw columns of size 650*400 mm at the intersection of the horizontal and vertical grids and beams with quick draw Column keeping all the stories on.

• Columns are Successfully added to the structure.

Step:-9

• Next we need to add the beams using the Quick draw beams option, as shown below.
• 

Step:-10

• Next we need to add the slabs using the Quick draw floor/wall option, as shown below.

Step:-11

• Now we go to the base plan and select all base joints.
• Next we select the Restraints from joint option, as shown below.
• Now we need to select the fixed joint and click on apply and then click on close button, as shown below.

Step:-12

• Next we need to select the load patterns from the define option, as shown below.

• Now we should add Dead load, live load, Brickwall load, Floor finshes and earthquake load, as shown below.

• Next we need to select eqx and click on the Modify Lateral Load, then the new tab appears.
• In this tab select X Dir and As per the IS 1893:2002, the seismic zone factor for Guwahati, Assam is taken as 0.36, as mentioned in the below table.
• And we need to select site type as lll, as shown below.
• Next click on the ok button.
• Similarly, do this for all the seismic loads such as eqx+, eqx-, eqy, eqy+, eqy-.

Settings for EQX

• Assign all options as given below
• Click 'OK'

Settings for EQX+

• Assign all options as given below
• Click 'OK'

Settings for EQX-

• Assign all options as given below
• Click 'OK'

Settings for EQY

• Assign all options as given below
• Click 'OK'

Settings for EQY+

• Assign all options as given below
• Click 'OK'

Settings for EQY-

• Assign all options as given below
• Click 'OK'

• Click 'OK'

STEP -12

Add Mass Source Data

• Click 'Mass Source' under the 'Define' tab

• Click 'Modify/Show Mass Source'

• Assign all options as given below
• Click 'OK'

STEP 13:

Assign Loads

Brickwall Load on Floors

• Select beams which undergo brick load
• Click 'Distributed' in the 'Frame Loads' under the 'Assign' tab

• Assign 'Brick Wall' load as 3.72 KN/m as shown below
• Click 'Apply'

Brickwall Load on Terrace and Mumty

• Select beams which undergo brick load
• Click 'Distributed' in the 'Frame Loads' under the 'Assign' tab

• Assign 'Brick Wall' load as 1.05 KN/m as shown below
• Click 'Apply'

Step-13

Live Load

• Select slabs which undergo 2 KN/m²
• Click 'Uniform' in the 'Shell Loads' under the 'Assign' tab

• Assign 'Live' load as 2KN/m² as shown below
• Click 'Apply'

• Select slabs which undergo 3 KN/m²
• Click 'Uniform' in the 'Shell Loads' under the 'Assign' tab
• Assign 'Live' load as 3 KN/m² as shown below
  • Click 'Apply'

Step:-14

• Click 'Uniform' in the 'Shell Loads' under the 'Assign' tab
• Assign 'Live' load as 1.5 KN/m² as shown below
• Click 'Apply'

Step:-15

• Click 'Live Load Reduction Factors' underthe 'Design' tab

• Select 'User Defined' and click 'Define'

• Assign all values as shown below
• Click 'OK'

STEP-16

Floor Finishes

• Select all slabs
• Click 'Uniform' in the 'Shell Loads' under the 'Assign' tab

• Assign 'Finishes' load as 1.5 KN/m² as shown below
• Click 'Apply'

Step-17

Diaphragms

• Click 'Object Type' under the 'Select' tab

• Click 'Floors' and press 'Select'

• Click 'Diaphragms' in the 'Shell' under the 'Assign' tab

• Select 'D1' and click 'Apply'

• Hence the diaphragms are assigned, as shown below.

STEP 18:

Modal Cases

• Click 'Load Cases' under the 'Define' tab

• Click 'Modify/Show Case'

• Assign all values as shown below
• Click 'OK'

STEP 19:

Response Spectrum

• Click 'Response Spectrum' in the 'Functions' under the 'Define' tab
• Select 'IS 1893:2016' and click 'Add New Function'

• Assign all values as shown below
• Click 'OK'

• Click 'OK'
• Click 'Load Cases' under the 'Define' tab

• Click 'Add New Case'

• Assign all values as shown below
• Click 'OK'

• Again, click 'Add New Case'

• Assign all values as shown below
• Click 'OK'

STEP :-20

Load Combinations

• Click 'Load Combinations' under the 'Define' tab

• Click 'Add Default Design Combos'

• Select 'Concrete Frame Design', and 'Convert to User Combinations'
• Click 'OK'

Step:-21

• Next we have to check the model by clicking the check model option, as shown below.
• After the model is checked, it will show us No warning.

STEP 22:

Run Analysis

• Click 'Run Analysis' from top menu

• Analyse the model using analyse option then click on check model the modelled structure is verified without errors and warnings.

STEP 23:

Model Tables

• From 'Model Explorer', select
• ANALYSIS RESULTS > Structure Output > Base Reactions > Table: Base Reactions

• Right click and then click 'Show Table'

EQX and EQY values equal to RSx and RSy values

• From 'Model Explorer', select
• ANALYSIS RESULTS > Structure Output > Modal Information > Table: Modal Participating Mass Ratio
• 
• Right click and then click 'Show Table'

• From 'Model Explorer', select
• ANALYSIS RESULTS > Structure Output > Modal Information > Table: Modal Periods And Frequencies

• Right click and then click 'Show Table'

STEP -24

Story Response Plots

• Click 'Story Response Plots' under the 'Display' tab

• Assign 'Display Type' as 'Max story drifts' and 'Case/Combo' as 'EQX'

• Assign 'Display Type' as 'Max story drifts' and 'Case/Combo' as 'EQY'

STEP -25

Longitudinal Reinforcing

• Next we have to start the beam design by selecting 'start design/check' option, as shown below.

STEP 26

Shear Reinforcing

STEP-27

Column Longitudinal Reinforcing

STEP-28

Column Shear Reinforcement

STEP -30

Export to SAFE File

• Click 'Story as SAFE V12 .f2k File' in the 'Export' option under the 'File' tab

• Assign all values as shown below
• Click 'OK'

• Give file name and click 'Save'

SAFE

STEP-1

• Open SAFE Software

STEP -2

Import the SAFE File

• Click 'SAFE .f2k Text File'

• Select the file and click 'Open'

• Then the file has been opened in safe 2020.

STEP-3

• We select the show loads from the display option,as shown below.

• After selecting the show load options, and the new tab will be visible, in that we select to dead_above as load pattern.

• Now we select Live_above as load pattern.

STEP -4

Material Properties

• Click 'Material Properties' under the 'Define' tab

• After selecting the materials the new tab appears, then we add new materials by selecting the add new materials options.
• Now we need to add material type as concrete and grade as M25.
• We enter weight per unit volume as 25 KN/m^3.
• WE enter modulus of elasticity as 25000 N/mm^2.

• Now we need to add material type as rebar and grade as HYSD 500.
• We enter weight per unit volume as 77 kn/m^3
• WE enter modulus of elasticity as 200000 N/mm^2

• Now we need to add material type as rebar and grade as HYSD 415.
• We enter weight per unit volume as 77 KN/m^3.
• WE enter modulus of elasticity as 200000 N/mm^2.

• So, materials are assigned.

STEP-5

• Now select Section Properties under Define Tab.
• Select Slab Sections.
• Select Add new properties in Slab Properties.

• After Selecting the new property, name the slab property as Pile_cap.
• We put the slab thickness as 800mm ans material as M25.

• After Selecting the new property, name the slab property as Pile_500.
• We put the slab thickness as 800mm ans material as M25.

• We have to add another slab propery as Column_stiff.
• We put the slab thickness as 800mm ans material as M25.

• Slab properties are assigned Successfully.

STEP-6

• Click 'Frame Section' in the 'Section Properties' under the 'Define' tab

Tie Beam

• Click 'Add New Property'

• Select 'Rectangular Section' and click 'OK'

• Assign all options as given below
• Click 'OK'

STEP -7

Add Point Spring Property Data

• Click 'Point Springs' in the 'Spring Properties' under the 'Define' tab

• We select the points to assign the springs for the piles.
• Now we select the springs from the support data from assign option.
• Next point spring properties tab will be visible.
• Next we select the modifiy/show property, then the new tab appears. We take for 490.87 in translational z.

STEP ;-8

Draw Slab Properties

• Click 'Quick Draw Area Around Point'
• Assign all options as given below
• Click all the necessary points

• Assign all options as given below

• Click all the necessary points

• Assign all options as given below

• Click all the necessary points

• Assign all options as given below

• Click all the necessary points

• Assign all options as given below

• Click all the necessary points

STEP :-9

Add Piles and Column

• Click 'Quick Draw Area Around Point'

• Assign all options as given below

• Draw column in the center point
• Assign all options as given below

• Draw column in the center point
• Assign all options as given below

• Draw the pile caps in the reference points

STEP :-10

Assign Point Springs

• Select the center points of all piles
• Click 'Springs' in the 'Joint' under the 'Assign' tab

• Select 'PSPR1' and click 'OK'

• We have to assign the point load from the column.
• Now we select the point loads from the load data from assigned option.
• Next the point load tab will be visible, in that we add the gravity load at Z-direction as 1071.53 KN.
• Next we enter the size of punching shear as (650X450 mm).

STEP :-11

Assign Tie Beam

• Click 'Quick Draw Beams'

• Click on each frame to assign beams

STEP :-12

Design Strips

• Click 'Add Design Strips' under the 'Edit' tab
• Assign all options as given below
• Click 'OK'

• Assign all options as given below
• Click 'OK'

STEP -13

Run Analysis

• Click 'Run Analysis' from top menu

STEP _14

Punching Shear

• Click 'Show Punching Shear Design' in the top menu

STEP -15

Top and Bottom Reinforcement

• Click 'Slab Design' in the top menu
• Assign all options as given below
• Click 'OK'

Layer A

Layer B

Pile Cap Reinforcement

Tie Beam Reinforcement