International Research Journal of Modernization in Engineering Technology and Science

e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science Volume:02/Issue:09/September-2020

Impact Factor- 5.354

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ANALYSIS OF A BUILDING FOR STRONG-COLUMN WEAK-BEAM CONCEPT BY USING E-TABS Mrs. K. Prafulla Devi*1, A. Hareesh*2, P. Tarun*3, S. Rajesh*4, A. Mazeed*5 *1Assistant

professor, Gudlavalleru Engineering College, Gudlavalleru, India.

*2,3,4,5Student,

Gudlavalleru Engineering College, Gudlavalleru, India.

ABSTRACT During past Earthquakes section plastic pivots are more noticeable than pillar pivots which offers ascend to worldwide basic harm and high dangerous danger. All the basic segments moves their powers through section and segment at that point imparts it to establishment to soil, so you can envision if segment bombs entire structure can crumple this is “Strong-beam Weak-column” concept. By making segment more second safe than radiates the plastic pivots movements to radiate and keeps away from the worldwide harm, for this situation just bar will give flexure as an indication of pillar harm and the individuals will have sufficient chance to empty the spot and bar disappointment will just restrict to a specific story.This concept is “Strong-column Weak-beam”. In this project RC frame of G+5 are analyse and designed. The design involves load calculations and analysing the whole structure by STAAD.Pro. Also, the frame investigated for “Strong-column Weak-beam” concept for zone-3 and medium soil (Based on Amaravathi location) and moment capacities are checked as per IS:1893-2016. For checking the performance of plastic hinges of columns and beams, Non-linear static analysis (Pushover analysis) is done in E-TABS and Base shear is checked for all frames.

Keywords: Earthquake, Pushover Analysis, Hinges, Moment capacity, STAAD Pro, E-TABS.

I.

INTRODUCTION

Pushover Analysis is a non-linear technique to gauge the quality limit of a structure beyond its cutoff state up to its ultimate strength. It can help exhibit how progressive failure in buildings most presumably happens and distinguish the mode of failure. Strong-Column Weak-Beam concept can be analyzed trough pushover analysis. The development of plastic pivots in beams helps to build the most wanted and suitable energy dissipating mechanism for structure in seismic conditions. If the plastic Hinges are developed on both ends of the columns then column is not able to spread the plasticity and collapses which can lead to global failure. The building frame consists of number of bays and storey. A design and analysis of R.C building of G+5 storey frame work is taken up. The size of building is 18.55*17.61m. The number of columns is 30. The sizes of the columns and beams are 0.3*0.4m and 0.23*0.4m respectively.

Size of the slab at each storey is 0.12m. Dead loads are taken from IS875:1987Part 1 in which floor finish is taken to be 1.5KN/m2@Roof level and 1.0KN/m2@Floor level. Imposed loads are taken from IS875:1987Part 2 in which Live load is taken to be 1.5KN/m2@Roof level and 3.5KN/m2@Floor level and Wall load is calculated as per bricks unit weight of 19.2KN/m 3.Grade of concrete is M30 and grade of steel is Fe415. Earthquake load is calculated as per IS1893:2016 in which the structure is situated in Zone-3.

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e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science Volume:02/Issue:09/September-2020

Impact Factor- 5.354

www.irjmets.com

Figure-1: Building plan

II.

METHODOLOGY

Generally seismic analysis is based on linear static analysis in which Response Reduction factor plays a major role in design as per IS:1893-2016. During the Earthquake redistribution of forces in column and beams in which the building damaged severely even designed for seismic loads. In this redistribution of forces can be analyzed by Non-linear static analysis (Pushover analysis). This is the second stage of seismic analysis in Earthquake Resistant Design. In this analysis can make columns more second safe than beams and redesign the structure and also rehabilitate the existing structures. The below hinge mechanism shows the behavior of the structure Force

Deformation Building performance is the combined performance of both structural and non-structural components of the building. Diverse execution levels are utilized to depict the building performance using the pushover analyses, which are described below.

Operational level (OL): According to this exhibition level structure are relied upon to support no lasting harms. Structure holds unique quality and solidness. Significant splitting is found in segment dividers and roofs just as in the basic components.

Immediate occupancy level (IO): Structures distributing this presentation level are relied upon to continue no float and structure holds unique quality and firmness. Minor splitting in segment dividers and auxiliary components is watched. Lifts can be restarted. Fire insurance is operable.

Life Safety Level (LS): This level is shown when some leftover quality and solidness is left accessible in the structure. Gravity load bearing components work, no out of plane disappointment of dividers and www.irjmets.com

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e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science Volume:02/Issue:09/September-2020

Impact Factor- 5.354

www.irjmets.com

stumbling of railing is seen. Some float can be seen with some inability to the parcel dividers and the structure is past prudent fix. Among the non-auxiliary components bombing danger mitigates yet numerous engineering and mechanical and mechanical frameworks get harmed.

Collapse Prevention Level (CP): Structures meeting this exhibition level are relied upon to have minimal remaining quality and solidness, yet the heap bearing auxiliary components capacity, for example, load bearing dividers and sections. Building is required to support enormous perpetual floats, disappointment of segments infill and railings and broad harm to non-basic components. At this level the structure stays in breakdown level.

III.

SOFTWARES USED

Staad.Pro:- This software is used for initial design of the building. As per this software based on loading, the beam column results are given below

Figure-2: Beam design

Figure-3: Column design

E-Tabs:- This software is used for Pushover analysis and shows the behavior of building due to redistribution of forces. The designed elements by Staad.Pro shows the Hinge mechanism whether the element safe or not.

Figure-4: Hinge mechanism in Push-X

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Figure-5: Hinge mechanism in Push-Y

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e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science Volume:02/Issue:09/September-2020

IV.

Impact Factor- 5.354

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RESULTS AND DISCUSSION

Table-1: Monitored displacement vs Base shear in Push-X

Table-2: Monitored displacement vs Base shear in Push-Y Monitored displacement vs Base shear tables shows the hinge mechanism and shows the various stages in which the hinge formation. We can observe that more hinges in collapse prevention state in push-y direction as compared to push-x direction. So, redistribution of forces in Y-direction is more.

Figure-6: Sa vs Sd in Push

Figure-7: Sa vs Sd in Push-Y

Spectral acceleration(Sa) vs Spectral displacement(Sd) graphs show the performance of the structure.

When the Demand curve reaches the Capacity curve at a point is performance point. In Push-Y direction the performance point does not clearly known because a more number of Hinges is in collapse prevention state. This show the structure safe in push-x direction but in push-y direction partially unsafe. So, we can get the safe condition when the structural elements change the dimensions based on the results in push-y direction shows. www.irjmets.com

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e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science Volume:02/Issue:09/September-2020

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CONCLUSION

The behavior of RCC frame building is acceptable as indicated by the intersection of the demand and capacity curves and the distribution of hinges in the beams and columns.

In this analysis, the performance point shows safe design in Push-X and slightly unsafe in Push-Y direction.

In this analysis results the cross section of beams and columns matters some changes in designing based on “Strong-column Weak-beam” concept which is systematically represented by the hinges formed during pushover analysis.

Base shear vs Monitored displacement table shows the hinge mechanism and which shows less no.of hinges in collapse prevention state in Push-X direction and more no.of hinges is in collapse prevention state in Push-Y direction.

The analysis shows moment capacity ratio plays a major role in increasing the ductility of column and moment resistivity of column is increased as per the code guidelines.

Spectral displacement(Sd),Spectral acceleration(Sa) and Time period(T) tabular values are used to design the unsafe elements in structure in particular directions.

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Impact Factor- 5.354

REFERENCES

Indian Standard Plain And Reinforced Concrete - Code Of Practice (Fourth Revision) Is: 456 -2000.

To Study Irregularities In Structures Analyze And Design Of G+5 Storied Structure As Per Code Is: 1893-2016 Provision Is 13920—2016 Ductile Detailing Of Reinforced Concrete Structures Subjected To Seismic Forces Is-875(Part-1) : 1987 Indian Standard Code Of Practice For Design Loads (Other Than Earthquake) For Buildings And Structures Part 1 Dead Loads — Unit Weights Of Building Materials And Stored Materials.

Is-875(Part-2): 1987 Indian Standard Code Of Practice For Design Loads (Other Than Earthquake) For Buildings And Structures Part 2 Imposed Loads Theory Of Structures By Ramamrutham For Literature Review On Kani’s Meathod Sp-16: Design Aids For Reinforced Concrete To Is: 456-L 978 R.C.C. Designs (Reinforced Concrete Structures) By Dr.B.C.Punmia, Ashok Kumar Jain, Arun Kumar Jain (Tenth Edition), Laxmi Publications (P) Ltd. Building Planning And Drawing By Dr. N.Kumaraswamy And A. Kameswararao (Fourth Revised And Enlarged Edition: 2010), Charotar Publishing House Pvt. Ltd. Autocad-2016.

Staad Pro Software.

E-Tabs Software

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