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

DESIGN AND 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

Aim:

To carryout modelling, analysis, design, and preparation of construction drawings of a G+3 RCC building situated in Guwahati Assam.

Introduction:

• ETABS is an engineering software product that caters to multi strorey building analysis and design.
• SAFE represents the state of art in three dimensional finfite element technologies for structural engineering.
• Here, in this project we are carrying out the design analysis of a G+3 building situated in Guwahati, Assam using ETABS software and then foundation design is carried out using SAFE software.

Procedure:

Initially open the ETABS application and click on the new model option from the file menu.

Now in the model initiation window desired units, Design codes which are to be used was selected and then click OK.

In New Model Quick templates under grid dimensions select the custom grid spacing and then click edit grid data.

The grid dimensions were inserted according to drawing file as follows and click OK.

In New Model Quick templates under Story dimensions select the custom story data and then click edit story data.

Now input the storey details as given in question and story 3 was selected as the master story and was applied to rest story and then click OK.

Plan View and 3D of the same is as below

Now to define the properties of elements, go to define menu and then select material properties. The grade of concrete was selected and click ok.

The material property data dialogue box will show up, ensure all the data’s are correct and then click Ok at the bottom.

Similarly HYSD 500and HYSD 415 steel was added.

Steel and Concrete properties was added to the list now as shown and then click OK.

To add frame members like beams, columns and slab go to Define Properties- Section Properties- frame sections options. From the frame properties dialogue box click on add new property option.

From the frame property shape type select the rectangular concrete option and click OK.

Beam details was provided as shown in figure and then click on Modify/ Show reinforcement under reinforcement section.

Beam reinforcement data’s:

Select M3 Design Only (Beam) and chose the rebar materials as shown and click OK.

In the similar manner apply the column data’s as shown below

Column reinforcement data:

Frame properties

To design the slab initially For Select Slab section from the section properties under Define menu.

Select add new property option.

Slab properties like thickness and other details are added as shown below and then click OK.

Slab properties:

So all the properties of frame members have been added correctly, now we have to place the structural members. For this select quick draw column option from the tools available at the left side of the screen and place the columns at all the grid intersections. Also select all storeys at the right bottom of screen to apply it to all storeys.

Now to Change the base connections initially go to the base view in the plan and select the base view. Now in assign tab- select joints- restraints. Now from the dialogue box that appears select fixed connections and then click OK.

After placing columns, Beams (the quick draw beams option beams) was placed followed by slabs (Quick draw floor option slabs).

To assign loads to the structure, select define followed by load patterns to open the Define load pattern dialogue box.

The various loads which are applied are 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 III, as shown below.
• Next click on the ok button.
• Similarly, do this for all the seismic loads such as EQx+, EQx-, EQy, EQy+, EQy-

In order to assign the loads, select the frame in which AAC brick wall falls and provide 3.5kN/m^2

Live loads were applied to slabs next.

As per IS 875 in residential buildings its 2kn/m^2 for rooms and bathrooms.

In the same way select slabs to assign floor finish which is 1Kn/m^2 for all rooms

To assign mass source to model follow these steps.

In define menu select mass source options to open the mass source dialogue box.

Now select Modify mass source data option and click OK

Now mass source data was provided as shown and load pattern was also added to it.

Response Spectrum was defined next.

New function was defined as per the IS 1893 for response spectrum analysis.

Load Case:

It was defined for both RSx and RSy

Load combinations:

Select add default design combos option

Tick on concrete frame design and convert to user combinations option.

The default load combinations are now loaded

To assign diaphragm to the model follow these steps:

In assign menu select Shell followed by Diaphragm to open the shell Assignment diaphragm dialogue box

Select D1 from the diaphragm assignments and click apply followed by OK.

The Diaphragm D1 is applied and is as shown below.

To check the model for errors, go to Analysis tab and select check model.

After the analysis of the model

Storey response plot:

For this go to Display-Story Response Plot- Maximum Storey drift

Beam design check is performed by selecting the Start design/check option

From the design display info option select the longitudinal reinforcement option

Beam Shear Reinforcement

Column Longitudinal Reinforcement

Column Shear Reinforcement

In order to export the ETABS model into SAFE click on file – Export – Story as SAFE V12.f2k file option

Save the file to desired location

Now open SAFE and import the F2K file

The file is now ready to work in SAFE

Materials for concrete (M25) and Rebars Fe 415 and Fe 500) was defined next as shown.

Slab properties was defined next like the Pile Cap, Pile and Column

The pile caps, Piles and Columns was applied next

Soil properties was assigned next as shown

Recheck for design preferences and run the design analysis

From the display option select show punching shear design or press F10.

If value is less than 1 its safe, If its greater than 1 then we have to increase the pile cap size

In the display menu click on Show slab design and then apply the settings as shown and click apply.

Slab strip design results

Results:

G+3 hostel was designed and analysed in ETABS

Foundations was designed and analysed in SAFE