Project 1_Comparative study of different storey buildings for Seismic forces

Aim : Comparative study of different storey buildings on different conditions for Seismic forces.

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.

• Etabs is totally run based on the IS codes which are IS - 456 ,IS - 800 , IS 1893..

in this study we have to analyze the following factors.

• Factors influencing the dynamic characteristics of a building
• Factors influencing the Natural Period of a building
• Factors influencing the Mode shape of oscillations

Procedure :

for A - K

• open the Etabs software create new sheet with built in settings units are metric SI .
• create the grids in x direction with A -E and in Ydirection 1-4 with the spacing of 4m
• enter the story data and ceate 25 stories each with 3 m height .
• define the the material properties of concrete as M30 grade and steel as HYSD 415.
• define the section proerties of frame properties are Beam size is 300 X 400 mm and columnn size is 400X400mm .
• similarly define the slab properties are thickness is 150mm.
• also define the load pattrens as dead ,live load , wall (superdead load) ,EQ x and EQ y those are seismic loads .
• next , use quick drawa option draw the columns,beams,slabs (which are not assign to base and plinth stories) based on the grids.
• then we have to assign the joints at the bottom of columns here they given pinned connection.
• after that assign the loads - frame loads to beams which are wall loads with 10 kN/m and shell loads to the slabs which are live loads with 3 kN/m2.
• also assign the mass sources to the all stories.and assign diaphroms to the floors for centre of mass for slabs.
• then modelleing is completed start the run analysis (F5).
• check resulsts and deviations and diagrams of structure.
• Results are given below.
• then save it in a folder name as Model -A ,after that again save as model -B
• make the changes are given in problem ,create the stories 5.and run the analysis and sve in folder
• then save as it model -C ,make the changes are in column size as 550 x 300 mm,those are oriented in X direction.angle 90' then run it .
• then save as it model - D,make the changes are in column size as 550 x 300 mm,those are oriented in Y direction.angle 0' then run it.
• save as it model - E ,make the changes are 10 story building with column size as 600x600 up to 5th floor 6 - 10 th is 400x400 mm size columns are used.then run it and sve.
• save as it model F,make the changes which are same column size 600x 600 u to 10th floor.then run it save.
• save as it model G ,make changes are 25 storys building with column size as 800x800 up to 10 th floor and provide 600x600 mm size column 11 - 20th floor ,and provide the 400x400 size columns are 21- 25 th floor.run and analysis saveit.
• save as it model H ,make changes are same column size 800x800mm provide up to 25 th floor ,then run and save the results.
• save as it model -J make the imposed mass of building 10% of building H , 3.3kN/m2.run and save
• save as model -k , make the imposed mass of building 10% of building H , 3.6kN/m2.run and save

Results :