Comparative analysis of multi storey building with and without soft storey for seismic actions

Published on 16 Apr 2022. Written by Akshay

Due to the current development in the field of the construction industry, it led us to construct high rise buildings.

Usually, in traditional practice, all the columns are projected downwards. Thus, there is no extra space for usage in the buildings. Because of this, some developments like parking facilities and play area is not available in the buildings.

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To overcome this, the idea for a soft story is developed. The structure will have some space in the bottom story and other places also that can be used for various features.

Since the ground floor is full empty with only a limited number of columns there are chances of building failure under seismic conditions.

During past earthquake records, a huge devastation of engineered systems and facilities has occurred in soft-story buildings. It has exposed some serious deficiencies in the primary design and construction practices.

This soft story structure creates major weak points in a structure. When an earthquake occurs it causes damage to the whole building. It may even cause serious structural damage along the elevation of the building also.

Now for further development, these soft-story buildings can be built in shapes like M, L, etc. but special care is to be taken about the shape of the building.

Parameters to be considered in the design are based on shear, story drift, time-period, natural frequency and bending moment.

After analysis, these buildings are strengthened by providing suitable braces, dampers and infill walls accordingly.

The methodologies used are equivalent static and response spectrum analysis

The design values and various values like zone factors, important factors, and acceleration values are referred to as per the IS 1893(Part1)-2002

Software required:

• SAP-2000
• E-Tabs

Objectives:

• To perform static and dynamic analysis on the proposed RC multi-story building without soft-story using SAP and E-Tabs.
• To perform static and dynamic analysis on the proposed RC multi-story building with a soft story using SAP and E-Tabs.
• To assess and compare the results of building with and without the soft story.
• To provide X bracings of concrete and steel to resist building against seismic action.

Conclusion:

• When a systematic experiment is performed it is observed that at bottom stories the concrete bracings are stiffer than steel bracings.
• The story displacement of the braced building is less as compared to the soft story building thus the overall response of the building decreases.
• The results obtained in E-Tabs are more accurate than SAP-2000.

Kit required to develop Comparative analysis of multi storey building with and without soft storey for seismic actions:

• etabs
• SAP2000

Technologies you will learn by working on Comparative analysis of multi storey building with and without soft storey for seismic actions:

• Construction Management
• Analysis

Any Questions?