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

AIM:

To design and analyse of G+3 hostel building in ETABS and Foundation in CSI SAFE.

Introduction :

• The procedure analysis and design of a given building will depend on the type of building, its complexity, the number of stories etc.
• First architectural drawings of the building are studied, structural systems are finalised sizes of structural members are decided and brought to the knowledge of the concerned architect.
• The procedure for structural design will involve some steps which will depend on the type of building and also its complexity and time available for structural design.
• The following data is needed before designing the structural design:-
• A set of architectural drawings
• Soil investigation report
• Location of place or city to decide wind and seismic load condition
• Data for lifts, water tank on top of the building and roof loading and its features.

PROCEDURE:

• ETABS Modelling:
• To design and analyse the hostel building first thing that we have to do is to open the ETABS software.
• After opening the ETABS software there will be an option called New Model click on that option.
• After clicking that option there will be a dialogue box named Model Initialization and in that dialogue box fill in the necessary data regarding the codes that we are going to use to design the given hostel building just as shown in the below given image below.

• A new model has been opened, so after opening the model now we have to edit the story data and the grid data accordingly.
• After that there will be another dialogue box named New Model Quick Templates, in that dialogue box there will be another option called Custom Grid Spacing check on that option after that there is another option called Edit Grid Data.

• And now there will be another dialogue box named the Grid System Data, in that dialogue box provide the grids in both directions according to the given architectural plan.

• After adding the grids we will be adding the stories as this building is a G+5 building now add the stories there is a dialogue box named the New Model Quick Templates, in that dialogue box there will be another option called Custom Story Data to check on that option after that there is another option called Edit Story Data.

• After this there will be another dialogue box named the Story data, in that dialogue box edit the number of stories the story's height and other relevant data.

• After setting the grid system and the story data this is how it will be looking like in the plan view and the 3D view.

• After this, we will be defining the Materials and the Section Properties.
• So to assign the materials we first need to go to the Define menu then there will be another option called Material Properties click on that option.
• After clicking on that option there will be a dialogue box named the Define materials in that dialogue box there will be an option called Add new material.

• After that, there will be another dialogue box named the Add New Material Property in that dialogue box fill the all appropriate data in that dialogue box.

• After that, there will be another dialogue box named Material Property Data in that dialogue box fill in the appropriate data that we need for designing purposes.
• In that dialogue box name the material as M25 and all the other data.

• And then click OK, M25 concrete material has been added to the material list.

• After adding M25 now have to add the rebar material, so to do that go to the Define material dialogue box and click on the option Add New Material.

• After this, there will be another dialogue box named the Add New Material Property in that dialogue box fill the all appropriate data in that dialogue box.

• After that, there will be another dialogue box named Material Property Data in that dialogue box fill the appropriate data that we need for designing purposes.
• In that dialogue box name the material as HYSD Grade 415.

• And then click OK, Rebar HYSD Grade 415 material has been added to the material list.

• After adding HYSD Grade 415 now we have to add another material, so to do that go to the Define material dialogue box and click on the option Add New Material.

• After this, there will be another dialogue box named the Add New Material Property in that dialogue box fill the all appropriate data in that dialogue box.

• After that, there will be another dialogue box named Material Property Data in that dialogue box fill the appropriate data that we need for designing purposes.
• In that dialogue box name the material as HYSD Grade 500.

• Then click OK, Rebar HYSD Grade 500 material has been added to the material list.

• Now that all the materials have been added to the list we have to define the section properties.
• So to define the section properties just go to the Define tab there will be a drop-down list and in that list, there will be an option called Section properties click on that option after that there will be another drop-down list in that list there will be another option called Frame Sections just click on that option.
• After this there will be a new dialogue box named the Frame Properties, in that dialogue box there is an option called Add New Property.

• Now we will be adding the section's properties like beam, columns etc.

COLUMN (450 mm X 650 mm):

• After clicking on the option Add New Property there will be another dialogue box named as the Frame Property Shape Type, in that dialogue box choose the shape of the column here I will be choosing a rectangular shape.

• After that, there will be another dialogue box named the Frame Section Property Data.

• In that dialogue box, there is another option at the right side of the screen and that option is Modify/Show Rebar just click on that option then there will be another dialogue box named Frame Section Property Reinforcement Data.

• And now again in the same dialogue box there is another option called Modify/Show Modifiers, so in that dialogue box put moment of inertia along the 2 and 3 axes as 0.7% because for the column moment of inertia reduces by 0.7% according to the IS code.

BEAM 250mm X 300 mm:

So to add the beam to the list go to the Frame Properties, in that dialogue box, there is an option called Add New Property.

• Now we will be adding the sections properties for the beam 250 mm X 300 mm.
• So after clicking on the option Add New Property there will be another dialogue box named as the Frame Property Shape Type.

• After that there will be another dialogue box named the Frame Section Property Data just as shown in the below given image below:

• In that dialogue box, there is another option at the right side of the screen and that option is Modify/Show Rebar just click on that option then there will be another dialogue box named Frame Section Property Reinforcement Data.

• And now again in the same dialogue box, there is another option called Modify/Show Modifiers, so in that dialogue box, the moment of inertial along the 2 and 3 axis is 0.35% because in the beams the moment of inertia reduces to 0.35% according to the IS code.

SLAB 150 mm Thick:

• Now we will be adding the slab, and to add the slab first to the Define menu then there will be a drop-down list in that list there will be an option called Section Properties.
• After this there will be another dialogue box named as the Slab Properties, in that dialogue box there is an option called Add New Property.

• After this, there will be another dialogue box named Slab Property Data.

• For the staircase, we will be providing a slab of 175mm thickness, and to add the slab for the staircase we will have to add the new property.

• After adding the section properties we will be drawing the slab, columns and beams in the given plan by using the quick draw tool which is provided in the software.

COLUMNS VIEW:

BEAMS VIEW:

SLAB VIEW:

• Now we will be assigning the load patterns:

Load Patterns:

LIVE LOADS:

• To assign the loads we need to go to the Assign Menubar there will be a drop-down list in that list there will be an option called Shell Loads.
• Then there will be a new dialogue box named the Shell Load Assignment-Uniform, in that dialogue box Fill the all relevant data.
• Now select the floors and add the Live loads to the structure.
• Here we will be providing 2 KN/sq.m as a live load for the rooms and the dormitories of the hostel building according to the IS 875 part 2 for the residential building.
• As per the IS code for the hostel building:

LIVE LOAD FOR CORRIDOR:

LIVE LOAD FOR TERRACE:

FLOOR FINISH:

AAC BLOCK LOADS:

AAC LOAD FOR TERRACE:

• To define the mass source the first thing that we need to do is that go to the Define option and there will be a drop-down list.
• After that, there will be another dialogue box named Mass Source and in that dialogue box, there is an option called Add New Mass Source.

• After that, there will be another dialogue box named Mass Source Data.

MASS SOURCE:

• After assigning the mass source we will be assigning the Modal case.
• To do that first go to the Define menu then there will be a drop-down list in that list there is an option called Load Cases.
• Then there will be another dialogue box named as Load Cases in that dialogue box there will be an option called Add New Cases.

• Then there will be another dialogue box named the Load Case Data, in that dialogue box fill in the data just as shown in the below given image below:

MODAL CASE:

• And now we will be defining the Diaphragm.
• Firstly select all the floors and then assign Diaphragm.
• So to assign the diaphragm, we first need to go to the option Assign then there will be a drop-down list in that list there is an option called Shell click on that option then there will be another list in that list there will be an option called Diaphragm.

DIAPHRAGM:

• And now we will be assigning the Response Spectrum.
• To assign the response spectrum just go to the option Define and then there will be a drop-down list in that list there will be an option called Function just click on that after clicking on that option there will be another list in that list there will be an option called Response Spectrum.

• After this there will be another dialogue box named Define Response Spectrum Functions, in that dialogue box there will be an option called Add New Function and Choose Function Type To Add as IS 1893:2016.

• After that there will be another dialogue box named as the Response Spectrum Function Definition- IS 1893-2016.

RESPONSE SPECTRUM FUNCTION:

• Now we have to define the Load Cases, to define the load cases first go to the define option then there will be a drop-down list in that list there will be an option called Load cases.
• Then there will be another dialogue box named as Load Cases in that dialogue box there will be an option called Add New Cases.

• Then there will be another dialogue box named the Load Case Data.

• Now we will be defining the load combinations.
• To define the load combination just go to the define tab there will be a drop-down list in that list there will be an option called Load combinations.
• Then there will be a new dialogue box named as Load Combinations in that dialogue box there will be an option called Add Default Design Combos.

LOAD COMBINATIONS:

• Now we will be checking the models if there are any warnings, if there are then correct the warnings and if not go ahead with the planning.

CHECKING THE MODEL:

RUN ANALYSIS:

MODAL RESPONSE CHECK:

STORY DRIFT CHECK:

EQx:

EQy:

BASE REACTIONS:

COMPLETE DESIGN:

LONGITUDINAL STEEL REQUIREMENT:

SHEAR REQUIREMENT:

• Now we will be moving to the last part of the designing which is foundation designing using the SAFE software.

SAFE SOFTWARE:

• First, we need to export the file from the ETABS software.
• So to export the file from the ETABS software, first go to the option File then there will be an option called Export click on that then there will be another list in that list there will be another option called Story as SAFE V12.f File.

• Then there will be another dialogue box named Options for Export to SAFE.

• Now save the file according to our preferences and now go to the SAFE software and open the file.

GIVEN DATA:

Column Size: 450 mm X 600mm and 600 mm X 450 mm.

Soil Type: III.

Length of the piles: 10m.

Pile Diameter: 500 mm diameter.

Load Carrying Capacity of Pile: 280 KN.

Pile Cap - Slab type _ Matt of 50 mm thickness.

Column Cap - Slap type - Stiff of 500 mm thickness.

Pile length: 16 mm

• Soil Bearing Capacity: 150 KN/sq.m.
• So the first step is to define the materials and the section property.

After that, there will be another dialogue box named the Define Materials.

• After this, there will be another dialogue box named Add New Material Property.

• Now we will be adding another property for the rebars.
• Once again go to the dialogue box Define Materials, in that dialogue box, there is an option called Add New Material.

• After this, there will be another dialogue box named Add New Material Property.

• And now we will be adding the section properties.
• So to add the section properties first we need to go to the defined bar then there will be a drop-down list in that list there is an option called Section Properties click on that option from the list after that there will be another list named the Slab Section.
• So now we will be first adding the Pile Cap. After clicking the option Slab Section there will be another dialogue box named the slab properties in that dialogue box there will be another option called Add New Property.

• Then there will be another dialogue box named the Slab Property Data.

PILECAP of 800mm Thickness:

PILES of 500 mm Diameter:

STIFF COLUMN SECTION:

FRAME SECTION FOR TIE BEAMS:

• After that we have to define the Point Spring property to do that just go to the option Define and then there will be a drop-down list and in that list, there is an option called Spring properties click on that option and after that, there will be another list in that list click on the option Point Spring.

• After that select the Quick areas around the point, then there will be a dialogue box and in that dialogue box give the shape of the object as a Rectangle slab and give the properties of a Pile slab.
• Here we will be using three sizes of footing i.e. 2.5X2.5m,6.5X4.5m and 6.5X6.5m.
• Place all the columns using the above procedure to create different sizes of footing.
• Now draw the slab using the quick tool and after creating the slab for the footing.

• Columns also have been placed as shown in the below-given image below,

• After assigning the columns assign the piles just as shown in the below given image below,

• Now we have assigned the spring constant.

CHECK FOR SETTLEMENT:

• According to the codebook, a total settlement of 25 mm is allowable not more than that. So the allowable settlement in our case is less than the permissible allowable limit. Hence OK.

CHECK FOR PUNCHING SHEAR:

• According to the IS code the punching value should not cross the unit value, so in our case, the punching shear value is less than the unit value. Hence OK.

RESULT:

• G+3 Hostel building design is designed and analysed in ETABS.
• The foundation is designed and analysed in SAFE.