Structural Modelling using Etabs 2018

PROJECT:-  Structural Modelling using Etabs 2018

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. Basic or advanced systems under static or dynamic conditions may be evaluated using ETABS. For a sophisticated assessment of seismic performance, modal and direct-integration time-history analyses may couple with P-Delta and Large Displacement effects. Nonlinear links and concentrated PMM or fiber hinges may capture material nonlinearity under monotonic or hysteretic behavior. Intuitive and integrated features make applications of any complexity practical to implement. Interoperability with a series of design and documentation platforms makes ETABS a coordinated and productive tool for designs which range from simple 2D frames to elaborate modern high-rises.

Once modeling is complete, ETABS automatically generates and assigns code-based loading conditions for gravity, seismic, wind, and thermal forces. Users may specify an unlimited number of load cases and combinations.

Analysis capabilities then offer advanced nonlinear methods for characterization of static-pushover and dynamic response. Dynamic considerations may include modal, response-spectrum, or time-history analysis. P-delta effect account for geometric nonlinearity.

Given enveloping specification, design features will automatically size elements and systems, design reinforcing schemes, and otherwise optimize the structure according to desired performance measures.

QUESTION:-

The architectural drawings for a G+7 residential building in zone 5 has been provided. The floor plan is the same for all 7 floor levels. Possible column positions have also been provided. Conceptualize a framing plan layout and then model the building in Etabs. The following architectural drawings have been provided:

• Typical floor plan – The location and thickness of the brick walls and the use of the
  space (for estimating live load) can be obtained from this plan
• A building section through the staircase and lift core is provided
• Parking layout in the ground floor – the column/shear wall arrangement must not
  obstruct entry/exit of vehicles.
  The following loadings are to be taken into account:
• Brickwall made of AAC blocks
• Finishes – floor tiles of 75 mm thickness
• Live loads as per IS 875 part 2
• Water tank of 20 KL above the staircase at Mumty level
• Lift Machine room at mumty level above lift core

The structural model must comply with provisions of IS 1893 and IS 13920.
Run a modal response spectrum analysis and check analysis results of the etabs model for inter-storey drift requirements, vertical & planar irregularities, minimum shear wall requirements,maximum axial load ratio for column and shear walls, effective moment of inertia for beams
and columns etc.

Please note that the column positions shown in the architectural typical floor plan are only to provide an initial starting point for modelling. Participants will have to change its size, introduce shear walls, and add new vertical elements after running the analysis. You will have to run the analysis multiple times until a structural model is obtained that meets structural code requirements without compromising architectural functions. Also, there is no one ‘correct’ structural system for this challenge. There can be multiple possible solutions for this problem.

 

AIM:- To model and analyze the G+7 residential building from the given architectural drawings using the ETABS 2018.

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.
• Basic or advanced systems under static or dynamic conditions may be evaluated using ETABS
• ETABS modeling is the generalization that multi-story buildings typically consist of identical or similar floor plans that repeat in the vertical direction.
• Modeling features that streamline analytical-model generation, and simulate advanced seismic systems.
• Once modeling is complete, ETABS automatically generates and assigns code-based loading conditions for gravity, seismic, wind, and thermal forces.

PROCEDURE:-

• First we have to open 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.

 

• The above given data is according to the architectural file that have been provided to us with the challenge.
• Now that the grids have been arranged according to the given data,now we have to set the story data also.
• So in order to do so just click on the Custom Story Data and then click on the option Edit Story Data just as shown in the below given image:

  

• After clicking the Edit Story Data option there will be another dialouge box named as the Edit Story Data, and we need to add the stories upto the 7 floors so just add the stories just as shown in the below image:   

           

     

• Now fill the relevant data required just as shown in the below given image

 

• The story and the grids setup have been completed.
• So the plan view and the 3D view has been shown below in the image:

   

• After setting the grids and the story data now we need to define the materials and the Section Properties as well.
• So in order to set the material first we need to go to the Define option and there will be a drop-down list in that list there is another option called Material properties just as shown in the below given image:

      

• After clicking on the Material property there will be another dialouge box named as Define material,in that dialouge box just click on the option Add New Material just as shown in the below given image:

     

• After that there will be another dialouge box named as Add New Material Property fill the relevant data in that dialouge box just as shown in the below given image:

    In the above dialouge box type:

• Region : India.
• Material Type : Concrete.
• Standard : Indian.
• Grade : M30.

Just as shown in the below given image:

M30 CONCRETE:

   

• After adding the M30 concrete, now we will be adding the another material
• And to do that we need to click on the Add New Material option in the same dialouge box just as shown in the below given image:

     

• After that there will be another dialouge box named as Add New Material Property fill the relevant data in that dialouge box just as shown in the below given image:

    

• In the above dialouge box type:
• Region : India.
• Material Type : Rebar.
• Standard : Indian.
• Grade : HYSD Grade 500.

Just as shown in the below given image:

HYSD 500 for the Longitudinal Reinforcement:

   

• After adding the HYSD 500 for the longitudinal reinforcement now one more time we will be adding another material.
• And to do that we need to click on the Add New Material option in the same dialouge box just as shown in the below given image:

 

• After that there will be another dialouge box named as Add New Material Property fill the relevant data in that dialouge box just as shown in the below given image:

   In the above dialouge box type:

• Region : India.
• Material Type : Rebar.
• Standard : Indian.
• Grade : HYSD Grade 415.

Just as shown in the below given image:

HYSD 415 for the Shear Reinforcement:

   

• Now that all the materials have been added shown in the below given image:

   

• Now we will have to define the frame properties.We will be adding the columns,slabs shear walls etc.
• So in order to do that first we need to go to the option Define tab there will be a drop-down list in that list there is another option called Section Properties and then click on the option Frame section,just click on that option just as shown in the below given image:

      

• After clicking on the Frame section option there will be a dialouge box named as Frame Properties,click on the option Add New Property just as shown in the below given image:

     

• First we will be adding column of size 450X650, so in order to do that click on the option Add New Property and after that there will be another dialouge box named as Frame Property Shape Type in that dialouge box choose the Section shape as Concrete Regular and the Concrete frequently used shape as rectangle and just click OK just as shown in the below given image:

    

• After this another dialouge box opens named as the Frame Section Property Data just as shown in the below given image:

  

- In that dialouge box fill the relevant data related to the design.

General Data :

• Propert Name : C400*600.
• Material : M30.
• Depth : 600 mm.
• Width : 400 mm.

Just as shown in the below given image:

COLUMN 400*600 mm:

     

     

• Now just click on the option Modify/Show Modifiers,after clicking there will be another dialouge box that appears on the screen named as Property/Stiffness Modification Factors,in that dialouge box fill the all relevant data:

Property/Stiffness Modifiers for Analysis:

• The Moment of Inertia in case of the column about 2nd and 3rd axis was reduced to 0.70 just as shown in the below image:

   

• Now we will be adding another column with different size in order to do that first we need to go to the option Define tab there will be a drop-down list in that list there is another option called Section Properties and then click on the option Frame section,just click on that option just as shown in the below given image:

      

• After clicking on the Frame section option there will be a dialouge box named as Frame Properties,click on the option Add New Property just as shown in the below given image:

   

• First we will be adding column of size 400X600, so in order to do that click on the option Add New Property and after that there will be another dialouge box named as Frame Property Shape Type in that dialouge box choose the Section shape as Concrete Regular and the Concrete frequently used shape as rectangle and just click OK just as shown in the below given image:

    

• After this another dialouge box opens named as the Frame Section Property Data just as shown in the below given image:

    

- In that dialouge box fill the relevant data related to the design.

General Data :

• Propert Name : C400X400.
• Material : M30.
• Depth : 400 mm.
• Width : 400 mm.

Just as shown in the below given image:

COLUMN 400X400 mm:

 

   

• Now just click on the option Modify/Show Modifiers,after clicking there will be another dialouge box that appears on the screen named as Property/Stiffness Modification Factors,in that dialouge box fill the all relevant data:

Property/Stiffness Modifiers for Analysis:

• The Moment of Inertia in case of the column about 2nd and 3rd axis was reduced to 0.70 just as shown in the below image:

 

• We have added the columns as we can see at the above image.
• So after adding the column now we will be adding the beam.
• So in order to add the beams,we first need to go to the Define tab there will be a drop-down list in that list there is another option called Section Properties and then click on the option Frame section,just click on that option just as shown in the below given image:

   

• After clicking on the Frame section option there will be a dialouge box named as Frame Properties,click on the option Add New Property just as shown in the below given image:

   

• Now we will be adding Beams of size 250*450 mm and in order to do that click on the option Add New Property and after that there will be another dialouge box named as Frame Property Shape Type in that dialouge box choose the Section shape as Concrete Regular and the Concrete frequently used shape as rectangle and just click OK just as shown in the below given image:

   

• After this another dialouge box opens named as the Frame Section Property Data just as shown in the below given image:

   

- In that dialouge box fill the relevant data related to the design.

General Data :

• Propert Name : Beam250*450.
• Material : M30.
• Depth : 450 mm.
• Width : 250 mm.

Just as shown in the below given image:

BEAM 250X450 mm:

 

                                 

• After that click on the option Modify/Show Modifiers then there will be another dialouge box appears on the screen named as Property/Stiffness Modification Factor.
• In that dialouge box fill the appropriate data:

Property/Stiffness Modifiers for Analysis:

• The torsional constant was reduced to 0.001.
• The Moment of Inertia about 2nd and the 3rd axis was reduced to 0.35 according to the IS codes.

Just as shown in the below given image:

     

• After adding the beam 250*450mm now we will be adding another beams of size 300*500 mm.
• So in order to do that we first need to go to the Define tab there will be a drop-down list in that list there is another option called Section Properties and then click on the option Frame section,just click on that option just as shown in the below given image:

     

• After clicking on the Frame section option there will be a dialouge box named as Frame Properties,click on the option Add New Property just as shown in the below given image:

 

• Now we will be adding Beams of size 300*500 mm and in order to do that click on the option Add New Property and after that there will be another dialouge box named as Frame Property Shape Type in that dialouge box choose the Section shape as Concrete Regular and the Concrete frequently used shape as rectangle and just click OK just as shown in the below given image:

  

• After this another dialouge box opens named as the Frame Section Property Data just as shown in the below given image:

    

- In that dialouge box fill the relevant data related to the design.

General Data :

• Propert Name : Beam300*500.
• Material : M30.
• Depth : 500 mm.
• Width : 300 mm.

Just as shown in the below given image:

BEAM 300*500 mm:

   

    

• The column size 400*400mm and 400*600mm and the beams of size 250*450mm and 300*500mm has been added as we can see in the below image:

   

• After adding the columns and the beams in the given plan now we will be adding the slab of thickness 125mm.
• And in order to do so first we need to go to the Define tab there will be a drop down list in that list there will be an option called Section properties and another option called Slab section just click on the option just as shown in the below given image:

    

• After that a new dialouge box appears on the screen named as Slab Property,in this dialouge box there is an option called Add New Property just click on that option just as shown in the below image:

    

• After this an another dialouge box opens named as Slab Property Data just as shown in the below given image:

   

- In that dialouge box fill the relevant data related to the design.

General Data :

• Propert Name : Slab125.
• Slab Material : M30.
• Modeling Type : Membrane.

Property Data:

• Type : Slab.
• Thickness : 125mm

Just as shown in the below given image:

SLAB 125 mm:

   

• And similarly we will be adding the slab for the staircase of 200mm thickness.
• Do the same procedure as we had done for the slab 125 mm.

SLAB (For Staircase) 200 mm:

   

• Now after adding slab we will be adding Shear wall. And in order to add shear wall first we need to go to the option Define there will be a drop-down list in that list there will be an option Section Properties and then there will be anothet option called Wall Section just click on that just as shown in the below given image:

   

• After this there will be another dialouge box named as Wall Properties, in that dialouge box just click on the option Add New Property as shown in the below given image:

  

• After clicking on the option Add New Property there will be another dialouge box named as Wall Property Data just as shown in the below given image:

   

- In that dialouge box fill the relevant data related to the design.

General Data :

• Propert Name : Wall250.
• Wall material : M30.
• Modeling Type : Shell-Thin.

Property Data:

• Thickness : 250mm

Just as shown in the below given image:

SHEAR WALL 250 mm:

  

• All the materials and the frame properties have been added.
• Now we have to add the Columns,beams,slab and the shear walls using ETABS software tools.
• Now first lets add columns using the quick draw column tool available in the software to make make easy the positioning of the columns.
• So in order to use this tool to place the columns in a quick way so first go to the left side of the screen there is an option of quick draw columns just click on that icon just as shown in the below given image:

      

• Now place the column according to the given autocad file and the requirement of the question. But before placing the column make sure the settings are set to All stories. And now place the column accordingly just as shown in the below given image:

     

• Similarly add the beams just as shown in the below given figure:

    

• Now similarly add the secondary beams just as shown in the below given image:   

• After adding the secondary beams in the we will be adding the balcony wherever required,but before adding the balcony we have to add the slab just by using the option Quick draw floor plan/wall that are present in the left side of the screen just as shown in the below image:

      

• Now add the baloconies just as shown in the below image:

    

• After adding the slabs and the balcony now add shear walls in their appropriate locations just by using ETABS quick tools to draw the walls and this tool is present at the left-side of the screen just click on that option and draw the shear walls wherever needed just as shown in the below given image:

 

     

 

      

• Now we have to fix the connection at the base plan.
• So in order to do that first we need to go to the base plan and then select all the joints just as shown in the below given image:

 

• After that just go to the Assign toolbar then there will be a drop-down list in that list there will be another option called Joint click on that option after clicking on that option there will another drop-down list in that list there will be another option called restraints just click on that option just as shown in the below given image:

   

• After this there will be another dialouge box named as the Joint Assignment-Restraints, in that dialouge box choose the connection as the fixed connection and then press Apply and then OK just as shown in the below given image:

   

• 3D view of the model after assigning all the properties:

      

• After assigning all the properties like column,beam,slabs etc now we have to assign the load patterns.
• In order to assign the loads patterns first we need to go to the Deine tab then there will be a drop-down list in that list there will be an option called Load Patterns just as shown in the below given image:

   

• After clicking on that option there will be a dialouge box opened named as Define Load Patterns in that dialouge box assign all the loads i.e Live load,Dead load,super dead loads and the seismic loads just as shown in the below given image

 

All the loads have been added after adding the loads now go to the option Modify Lateral Loads and modify the seismic load so here the direction and the eccentricity were selected as the X-direction.

• The Response Reduction factor here taken as 5.
• Seismic Zone is 5 so take the value of Z as 0.36.
• Soil Type is given as III.
• And the importance factor for the residential building with less than 200 is taken as 1.
• And the Time Period is taken as 0.5 sec.

Just as shown in the below given image:

 

• And now we will be assigning the Brick Wall Load to the given structure.
• So in order to do that first we need to go to the option Assign then there will be a drop-down list in that list there is an option called Frame Loads click on that after clicking on that there will be another drop-down list in that list there is an option called Distributed just as shown in the below given image:

    

• After this there will be a dialouge box that appears on the screen named as the Frame Load Assignment- Distributed, in that dialouge box give the Brickwall load as  3.5 KN/sq.m. and then click Apply and then OK just as shown in the below image:

    

BRICK WALL LOAD-3.5KN/M:

     

• After applying the dead loads to the structure now we will be applying the live load.
• So in order to apply the dead load first we need to go to the option Assign and then there will be a drop-down list in that list there is an option called shell load click on that option after that there will be another list in that list click on the option Uniform just as shown in the below given image:

     

• After clicking the option Uniform there will be another dialouge box named as Shell Load Assignment-Uniform, in that dialouge box fill the relevant data.
• As we know that according to the IS code 875 there is a provision which says that in residential building the Live Loads that are applied to the rooms must be 2KN/sq.m.
• - And for the bathroom it should be 3 KN/sq.m.

So apply this provision in the above dialouge box and click apply just as shown in the below images:

• For Rooms: 2KN/sq.m

  

     

• For Bathrooms,staircase,lift : 3KN/sq.m

     

• Now that we have added the live load and the dead load to the structure,now we will be adding the floor finishes to the structure.
• For adding the floor finishes to the structure first select the slabs and then click the option Uniform there will be another dialouge box named as Shell Load Assignment-Uniform, in that dialouge box fill the relevant data.

• As we know that according to the IS code 875 there is a provision which says that in residential building the Live Loads that are applied to the rooms must be 1.5 KN/sq.m.
• - And for the bathroom it should be 3 KN/sq.m.

So apply this provision in the above dialouge box and click apply just as shown in the below images:

   

    

• Now after assigning the floor finish load now we will be doing the Live load reduction Factor according to the code.
• And in order to that first we need to go to the option Design and then go to the option Live Load Reduction Factor just as shown in the below given image:

     

• After that there will be another dialouge box named as the Live Load Reduction Factor,in that dialouge box there will be an option called User Defined just click on that option just as shown in the below given image:

    

• After that there will be another dialouge box named as the Live Load Reduction by Stories Supported,and in that dialouge box fill the relevant data just as shown in the below given image:

     

• According to the IS code it states that the buildings that are above the 10 stories,then we have to reduce the Live Load by 50%.
• And now we have to assign the Mass source for this structure.
• And in order to do that first we need to go to the option Define then there will be a drop-down list in that list there is an option called Mass source just click on that option just as shown in the below given image:

   

• After this there will be another dialouge box named as Mass source,in that dialouge box there will be an option called Modify mass source data just click on that option just as shown in the below given image:

  

• After this there will be another dialouge box named as Mass Source Data,in that dialouge box fill the appropriate data just as shown in the below given image:

  

• After assigning the mass source now we have to assign the diaphragm.
• And in order to assign the diaphragm we need to go to the Assign menu and after that there will be a drop-down list and in that list there is an option called Shell and then there will be another list in that list there is an option called Diaphragm just click on that option just as shown in the below given image:

   

• There will be a dialouge box named as Shell Assignment Diaphragm in that dialouge box select D1 and then click on the option Apply and then click on OK just as shown in the below given image:

   

• After assigning the diaphragm now we have to assign the load combinations and in order to do so we need to go to the Define menu then there will a drop-down list and there will be an option called Load combinations just click on that option just as shown in the below given image:

   

• Then there will be another dialouge box named as the Load combinations and in that dialouge box click on the option Add Default Design Combos.. just as shown in the below given image:

    

• After this there will be another dialouge box named as Add Default Design Combinations,in that dialouge box just click on the option Concrete Frame Design and Concrete Shear Wall Design and then click on the option OK just as shown in the below given image:

    

• And now there will be another dialouge box named as Combinations,in that dialouge box all the ETABS generation load combinations are there in that box just as shown in the below given image:

   

• And now select the pier labels and in order to do so first we need to go to the Assign menu then there will be a drop-down list in that list there will be an option called Shell click on that after that there will be another option called Pier label click on that option just as shown in the below given image:

    

• After this there will be another dialouge box named as the Pier Labels,in that dialouge box just add the labels or we can say that add the names for the shear walls just like P1,P2,P3,etc just as shown in the below given image:

    

• And assign the Pier Labels accordingly just as shown in the below given image
• And now we will be creating the modal analysis and in order to do that go to the Define menu there will be a drop-down list in that list there will be an option called Load Cases just click on that option just as shown in the below given image:

   

• Now there will be another dialouge box named as the Load Cases in that dialuge box there will be another option called Add New Cases just click on that option just as shown in the below given image:

  

• After clicking the add new case option there will be another dialouge box named as Load Cases in that box enter the data just as shown in the below given image:

    

• After this we will be assiging the spectrum analysis .
• And in order to do that just go to the Define menu then there will be a drop-down list and from that list just click on the option Functions and there will be another list and from that list just click on the option Response Spectrum just as shown in the below given image:

    

• And then there will be another dialouge box named as Define Response Spectrum Functions in that dialouge box Choose IS 1893:2016 from the option Choose Function Type and then click on the option Add New Function just as shown in the below given image:

   

• After clicking the option then there will be another dialouge box named as Response Spectrum Function Definatio-IS 1893:2016,in that dialouge box fill the data just as shown in the below given image:

    

The Response Spectrum Load Case in X-Direction: RSx

   

The Response Spectrum Load Case in Y-Direction: RSy

    

• Now after this we will check the model and do the Run Analysis.
• So in order to check the model we need to go to the Analyse menu click on that then there will be a drop down list in that list click on the option Check model just as shown in the below given image:

   

• Now click on the Check Model option and let the ETABS check the model for us just as shown in the below given image:

  

• Now that the model has been checked and there are no warnings:

    

• After checking the model with no warning do the Run analysis.

      

• And now we will be reviewing the analysis results to see if the model is structurally stable or not,or if this model needs a revision.
• So in order to do that first we have to check the Base Shear.

Base Shear Check:

• And to check the base shear just go to the Display menu then there will be a drop-down list in that list there is an option called Show table just click on that option just as shown in the below given image:

   

• After that there will be a dialouge box named as the Choose Tables for Display and in that dialouge box there will be an option called ANALYSIS RESULT click on that after that click on the Structure Output and then click on Base Reaction and then click OK just as shown in the below given image:

   

• After that there will be another dialouge box named as Base reactions and in that dialouge box it contains all the information regarding the Base reactions.
• And according to the codebook it is said that the response spectrum base shear must be at least equal to the same that is obtained by the linear analysis.
• So below are the given image from the both results in X and Y direction both:

 

 

Base shear scalling:

• As we can see from the above image that the response spectrum base shear is less as compared to EQx and EQy.
• So now what we have to do is increase the scale of the response scale spectrum load cases in X and Y so that it matches the base shear value.

 

Modal Participation Ratio:

• In order to check the modal participation ratio just go to the Display menu then there will be a drop-down list in that list there is an option called Show table just click on that option just as shown in the below given image:

   

• After that there will be a dialouge box named as the Choose Tables for Display and in that dialouge box there will be an option called ANALYSIS RESULT click on that after that click on the Structure Output and then click on Modal Information and then click OK just as shown in the below given image:

 

• Modal Participation ratio result is given below:

  

• So according the IS 1893 clause no.7.1 it states that the natural period corresponding to fundamental torsional mode of oscillation should not be greater that sum of two fundamental translational mode of oscillation (tx+Ty>Txy):
•  So we need to check the participation ratio of the two transational modes only.
• Therefore , Here Tx = 1.429 and Ty = 1.198; Txy= 0.814
• So the sum of these two translational mode of oscillation is 1.425 +1.198 = 2.623.
• So the sum of the two transational mode of oscillation is 2.623 which is greater than the value of Txy whose value is 0.814.

Therefore 2.623>0.814 ,hence there is no torsional irregularities.

• Now according to the IS 1893 clause 7.1 it also states that first three modes contribution should be more than 65% of the mass participation factor in each principal direction.

So here it is 0.678>0.65

Story Response Spectrum:

• In order to find the story response spectrum first we need to go to the display tab there will be an option called Story Responce plot just click on that option just as shown in the below given image:

    

• And now there will be another dialouge box change the Display type as Maximum story drifts and Case/Combo as RSx just as shown in the below given image:

 

• And do the same procedure to get the story drift in Y-direction i.e RSy just as shown in the below given image:

 

 

• So according to the IS: 1893,it suggest that the allowable maximum interstory story drift is of 0.4%.
• Now open the reaction tab from the top of the screen there is a tab click on that tab or just press F7 the new dialouge box name as Reactions opens,after that in the dialouge box select the earthquake load lowards the X-direction and then just click Apply and then OK just as shown in the below given image:

  

• And from the IS code we know that the shear wall should take at least 80% of the load.
• The base shear reactions are shown in the below given image:

   

• So in order to find the percentage value for the load capacity of the shear wall divide the base shear which is taken by shear wall with the base shear of the building,and if the number of the percentage is 80% then there is no need to provide more shear walls.
• But if the percentage is less than 80% then we have to provide more shear wall in our structure.
• Now here in our structure the number of shear walls is sufficient.
• Finally the model has been analysed successfully.

 

RESULT :-

• The structural model of the G+7 model is designed for given architectural planning using Etabs.
• Frame model which satisfies both code provision are analysed.
• Columns, shear walls and beam are provided in possible symmetrical way without much offsets.
• Analyses is done for modal number, base shear storey drift aspect ratio, irregularity etc.,
• As per the analyses result, building is bit flexible in y-axis, as shear wall are sufficient add additional column as provided in y-direction to meet the maximum storey drift limit.