Project 1_Comparative study of different storey buildings for Seismic forces

• AIM - Structural Modelling with the desired value of structure options given in the question.
• INTRODUCTION - The modelling is to be done according to the values in the particular etap software
• PROCEDURE - The step by step procedure is given in the images format respectively.
• RESULTS - Resultant Analysis values are to checked and verify in the structure output modal information i.e., dynamic characterstics, time period , mode shape etc.

• FACTORS INFLUENCING THE STRUCTURAL MODEL ARE GIVEN BELOW :-

1. Effect of Stiffness on Time period :-

Building-E (10 storey with varying column size) - Analysis results - 1.73s

Building-F (10 storey with uniform column size) - Analysis results - 1.73s

Building-G (25 storey with varying column size) - Analysis results - 4.18s

Building-H (25 storey with uniform column size) - Analysis results - 4.43s

Conclusion : the varying column sizes are more stable than uniform ones because the access mass is lumped at top story and the mass is directly propositional to lateral load acting on building that induces more lateral displacement of the building leading to greater time period.

2. Effect of mass on time period :-

Building-H 4.41 s (25 storey with 3 KN/sq.m imposed load) - Analysis results - 4.42s

Building-H 4.41 s (25 storey with 3.3 KN/sq.m imposed load) - Analysis results - 4.42s

Building-H 4.41 s (25 storey with 3.6 KN/sq.m imposed load) - Analysis results - 4.43s

Conclusion : mass is directly proportional to lateral force therefore it will definitely increase time period of the building.

3. Effect of building height on time period :-

Building-A (2 storey) - 0.6s

Building-B (5 storey) - 1.05s

Building-F (10 storey) - 1.73s

Building-H (25 storey) - 4.42s

Conclusion : As height increases it will increase time period height is directly proportional to time period as per fixidity.

4. Effect of column orientation on time period :-

Building-B orientation on Time period (All floors Column size 400x400) - Analysis result - 1.05s

Building-C (All floors Column size 550x300) oriented in X- direction - Analysis result - 1.148s

Building-D (All floors Column size I 300x550) oriented in Y- direction - Analysis result - 1.13s

5. Effect of Flexural stiffness of structural elements on mode shapes :-

Building B :-

Flexural Stiffness stiffness of Structural of Beams close to elements on Mode nil (Zero inertia) - Analysis result - 2.62s

Full Flexural Stiffness of Beams (Regular) -Analysis result - 1.04s

6. Effect of Axial stiffness Building-H of Vertical members on Mode shapes :-

Building H :-

Axial cross section for Columns is close to nil (Zero axial area) - Analysis result - 5.98s

Full Axial cross section for Columns (Regular) - Analysis result - 4.42 s

7. Effect of degree of fixity at Column base on Mode shape :-

Building B :-

Column support pinned (Regular) - Analysis result - 1.03 s

Column support fixed - Analysis result - 0.944 s

Thank you...................