SEISMIC ANALYSIS OF A CONCRETE BUILDING California State University at Los Angeles

SEISMIC ANALYSIS OF A CONCRETE BUILDING

California State University at Los Angeles

Belen Valencia

Art Chianello

Marlon CalderonFaculty Advisor: Rupa Purasinghe

Industrial Mentors: Fil Apanay and Roger Li

AnalysisOn Campus Concrete Shear Wall Building

Time History Dynamic Analysis Nonlinear Static Push Over Analysis

Maximum Displacements (in)San Fernando Earthquake @ Pacoima Dam

(PGA=1.17g, T1=0.1202, T2=0.0692, T3=0.0668)

Push-Over Analysis of Reinforced Concrete Shear Wall

• Push-over analysis can provide a significant insight into the weak links in seismic performance of a structure or component.

• RAM Perform 2D was the software used for this Performance Analysis.

Model of 3 story reinforced concrete shear wall using RAM Perform 2D. The wall is 36 feet high x 200 feet long x 8 inches thick with door openings.

Method of Analysis

• Inelastic material and Diagonal compression material properties were defined.

• Any limit states that were exceeded point to areas in the structure that can be retrofitted to seismically upgrade the structure.

ResultsPush-over (capacity) curve of reinforced concrete shear wall under uniform push-over loading. Limit States are shown on curve as red lines. First limit state reached was diagonal tension and shear of concrete, then roof drift. Base shear was 4877 kips at diagonal tension failure.

Capacity

Demand

ResultsDeflected shape of wall subject to triangular push-over load. Elements shown in red is first area of diagonal tension failure.

OBSERVATIONS

• Diagonal Tension/Shear failure is the controlling factor

–(as it is a long wall)

• RAM Perform 2D identified the locations within the wall that fail first.

Modeling as a Beam Column

• A Cross Wall - 25 ft x 36 ft x 8 in

• It was modeled using:• Load vs. Moment Curve (P-M curve)• Ram Perform-2D Obtained the capacity

spectrum push-over plot– Base Shear vs. Drift plot– Input an earthquake and analyzed how

the structure would react with the induced EQ load.

Ram PerformBase Shear (K) vs. Drift

Demand

Capacity

Summary

• We have shown - conventional TIME HISTORY ANALYSIS

- Non Linear Static Push Over Analysis for better understanding of the structure

THANKS to

• MCEER• CSLA ECST Computer Center (Jeff Cheam and Staff)