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

Aim: In order to construct and evaluate the provided building in ETABS 2018, a structural model that complies with IS 1893 and IS 13920 must be created. to create the ground floor framing plan and beam detailing, to design the pile cap and pile reinforcement details, to tie the beam connecting the pile caps, and to sketch the column reinforcements.

provided data: AAC blocks are used to build the wall. 280kN of pile capacity, M25 concrete, Fe 500 steel, and type 3 soil.

OVERVIEW: The program called Etabs is used to generate a structural model of a given building.

First, take note of the grid spacing values from the provided structural plans.

Next Run the structural model after creating it.

Examine the outcome and record the ETABS result values.

The model will then be exported to SAFE 2016 software so that the foundations can be designed.

PROCEDURE:

1. Initially, launch the etabs software, select File, then click on New Model.
2. A window for model initialization will open.
3. Choose the Indian codes by clicking on the "use built-in setting" and then click.
4. After selecting the custom grid data, click "OK."
5. After the values according to the plans are entered, our model will be prepared.
6. The next stage is to define the material. Add the concrete and rebar material specification by going to define, clicking on material properties.
7. The properties section needs to be defined in the following step. Add the beam and column specifications by going to define, clicking on section properties.
8. Each and every beam has a beam size of 450 x 600 mm.
9. For the periphery beams, 450 mm x 600 mm beams are provided in order to increase the building's torsional resistance.
10. For beams and columns, the moment of inertia should be decreased by 0.35% and 0.4% respectively.
11. Define the slab properties by defining the slab sections in the following step. Include the slab property as The slab for the stair case should be defined in a single direction.
12. Give the thickness of the stair case slab, which ranges from 175-225 mm, and define it.
13. Utilizing the beam command, draw every beam.
14. Use the column command to draw every column.
15. Slabs are drawn using the slabs command in the following step.
16. We now need to determine the best places for shear walls and how long they should be.
17. Indian guidelines state that a wall's length should be between five and two percent in each direction.
18. It is believed that the shear wall is 250 mm thick.
19. Proceed to declare the loads one by one now.
20. Add the loads after choosing the floors and beams.
21. Due to the usage of aac blocks, the AAC load is 3.5 kN/m.

The values for live loads for residential buildings are taken from Is 1875, Part 2.

According to IS 875 part 2's table 1

In the case of hostel buildings

Living areas, sleeping quarters, and dorms = 2 kN/m^2.

Laundry and Kitchen = 3 kN/m^2.

Public lounges and pool tables = 3 kN/m^2.

storage spaces = 5 kN/m^2.

cafeterias, dining areas, and restaurants = 4 kN/m^2.

Work spaces = 2.5 kN/m^2.

toilets and bathtubs = 2 kN/m^2.

corridors, hallways, and stairwells = 3 kN/m^2.

Terraces = 4 kN/m^2.

1. A reduction factor of 875 part 2 should be applied to the loads that have been imposed.
2. Two kN/m is applied because the live load at the roof floor needs to be decreased.
3. Every floor has a 2 kN/m floor finish applied to it.
4. According to IS 1893 Table No. 8, the significance factor for seismic loads should be 1.2 since the building.
5. The time period is determined using IS 1893 clause 7.6.2, with T=0.09h/sqrtd.
6. Tx= 0.09 * 16.85 / (66.7 · 0.5) = 0.184 sec. Alternatively, Ty=0.09*16.85/(13.3)^0.5=0.415 s
7. Define the load combinations now.
8. To define the mass source, go to define, click on mass source, add new, click on specified load data, select Include Lateral Mass and Lump Lateral Mass at Story Levels under Mass Options, and add multiplier 0.25 for LL and 1 for all dead and super dead loads in the load pattern.
9. Additionally, pick every floor and use diaphragm D1.
10. We must define the modal cases in the following step. To do so, go to define and select modal cases. select "Add New Model Cases." Choose Eigen and enter the necessary number of modes and form.
11. now select the response spectrum under "define function" and add a new function compliant with IS 1893-2016. Verify each and every value. Click "Ok."
12. Call the function the response spectrum or the IS function. There will be an IS function IS 1893-2016 tab; verify all the settings. soil type, significance factor, and seismic zone factor Select Linear X, Linear Y, then click "OK."
13. Click on Add new case and add RSX and Rsy after going to the define load cases screen.
14. choose the spectrum of responses. Click Add, choose IS as the function, Rx as U1, Rsy as U2, and IS as the function.
15. Proceed to define After selecting "load combinations" and "default design combo," select "create frame design," "convert to design combo," and "click ok."
16. Check the model now to see if there are any warnings, fix them, and then run the model.

Findings and conversation

• Select Display, Show Tables, Structural Data, and Click OK.
• Select the Analysis results structure output by clicking on Show Tables, then click OK.
• If the rX RY values are less than the Eqx Eqy, unlock the model, choose the base reaction, check the eqx eqy values, Rx and Ry values, and determine which values are larger. Next, go to define load case, erase the Rx RY cases, and then pick the load combinations and define that again.
• Visit the modal mass participation ratio and look up the numbers for the sum of these UX in U1 U2 and U3. For the first three modes, Uy UZ should be more than 65%.
• Navigate to the concrete frame design page and choose "Start" or "Check." Then record the specifics of the reinforcement values.
• 2. Choose the modal ratios of participation We have that at mode 7, where we have above 90%, so everything is good.
• 3. Choose the base reactions and ensure that the values of Eqx and Eqy are the same, and that the values of Rsx and Rsy are at least equal to Eqx and Eqy, respectively. If not, just divide the rsx values by the equation values to obtain the values that must be multiplied in the load cases rsx tab.
• Verify the percentage of shear walls. navigate to the base level and select Reaction. Values for ex and ey will be accessible. divide these figures in half. The overall base shear should be more than 90%. If you now include the shear walls in the proper orientations

Solution

Number of piles = Total Axial load / pile capacity = (1.5DL+1.5LL)/280 = numbers is the solution.

Since the definition of a spring includes piles, the spring constant is K=EA/L, or E=5000(fck)^0.5=5000(25).^0.5=25000 N/mm^2.

Pile area = 22/7*d^2=3.142*(500)^2/4=196375m^2 L-10000m K=25000*0.7855/16=306835.9N/mm== 419.

Pile spacing according to IS 2911 clause 6.6.2 is as follows: dia of the piles = 2.5*500 = 1250 mm; pile spacing

The next stage is to define the material parameters for both the reinforcement properties (Fe500 & Fe415) and the concrete material properties.

Decide on the values.

To define pile caps, pile diameter, and column, navigate to the defined section characteristics.

Add a new column that is specified as stiff and pile cap pile 500 as Mat.

When you click the quick sketch tool around the plots, a window will open where you may adjust the column sizes and locations. It is best to describe columns as stiff material.

The next step is to draw the pile caps. To do this, pick the pile caps command in the Quick Draw Slab menu and add it. It is best to describe piles and pile cap as rigid material.

select the pile caps and changed the rebar material as Fe 500.

select the pile caps and changed the rebar material as Fe 500.

Proceed to draw and select the location where the piles are to be drawn. A window will then open.

Once more, choose the fast dfaw around the pints. There, choose the circular slab property, add piles with a diameter of, in this case, 0.5 meters, and increase the points. Pick out these heaps and look inside once again for the rebar components.

We must now define each pile as a spring in order to define

particular soil spring characteristics Add a new property there, select Compression Only, and enter K=EA?L as the computation value.

After selecting every pile, pick Support Data, then Spring Properties, and then assign it.

select the pile caps and changed the rebar material as Fe 500.

Navigate to the "define" tab, choose "define beam," then specify the tie beams, whose thickness should match that of the pile caps.

Verify whether the rebar material, according to design preferences, is Fe 500.

Proceed to define the load combinations in detail. uls and sls

Navigate to the design and preferences for design.

Run the Analysis after saving the model.

Shapes that were deformed demonstrated how little deformations are.

Give the design strips a task.

Execute the analysis

Deformed shape: as every value is smaller than 25 mm, it is acceptable.

Proceed to the display and select the punching shear. Since the values we have are less than 1, everything will be OK.

select the pile caps and changed the rebar material as Fe 500.

Proceed to the display now and choose Slab Design.

For the X DIRECTION MIDDLE STRIP, all the reinforcement data will be given. The maximum reinforcement was as follows: 20 mm dia are provided; 29834 mm^2/m=29834/3.3=9041 mm^2=28 nos.; and 13326 mm^2/m=4038 mm^2=13 nos.FOR Y DIRECTION STRIP the maximum reinforcement was 20 mm in diameter. For the top, this equals 19926 = 3831 mm^2/m = 12 nos. of 20 mm dia. For the bottom, this equals 22784 mm^2/m = 4398 mm^2 = 14 nos. 20 mm diameter are offered.