Project 1_Comparative study of different storey buildings for Seismic forces

1. Ans:

AIM :

• To Drive the building in safe in earthquake the factors to consider for the process are ( Dynamic characteristic of a building, natural period of a building, Mode shape of Oscillations) These are the factors which influence the structure under seismic load.

Introduction :

• Draw Several building in ETABS and derive the multiple dynamic characteristic of buiding , natural period of a building and mode shape of oscillations.

Procedure :

Criteria	Model	Analysis result	Conclusion
Effect of stiffness on time period	Building of 10 story with unifrom size column	1.44
	Building of 10 story with varey in size of column	1.4
Effect of stiffness on time period	Building of 25 story with unifrom size column	3.90
	Building of 25 story with unifrom size column	3.54
Effect of mass on time	Building 25 storey with 3 kn /sqm	3.90
	Building 25 storey with 3 kn /sqm	3.915

Building 25 storey with 3 kn /sqm

3.926

Effect of building height on time period	Building of 2 storey	0.355
	Building of 5 storey	0.813
	Building of 10 storey	1.44
	Building of 25 storey	3.90
Effect of column orientation on time period	Building 5 storey ( same column of size 400*400)	0.74
	Building 5 storey ( same column of size 550*300) Along X direction	0.813
	Building 5 storey ( same column of size 300*550) Along Y direction	0.782

Criteria

Mode

Case

Analysis result

Conclusion

Effect of flexural stiffness of structural element on mode shapes	Building of 5 Storey	Flexural stiffnesse of beam close to nill ( zero inertia )	1.891
		Full flexural stiffness of beam	0.74
Effect of axiel stiffness of vertical member on mode shapes	Building of 25 storey	Axiel cross section for column is close to nill for 25 storey building.	5.931
		Full axiel cross section for column	3.90
Effect of degree of fixity at column base on mode shapes	Building of 25 storey	Column support pinned	0.74
		Column support fixed	0.669

• From the above result where taken from the model which was done in the detail in ETABS and the details are given below.

Result :

• From the above result the all building are determined the dynamic characteristics of a building , Natural period of a building and mode of oscillations are executed and result are given above.