Why do we match base shear in Etabs?
Therefore as mass increases base shear also increases. Based on experience in field base shear of a structure is almost equal to base shear produced in equivalent static method. So we go for matching.
What is the significance of base shear in relation with earthquake?
Base shear is an estimate of the maximum expected lateral force on the base of the structure due to seismic activity. It is calculated using the seismic zone, soil material, and building code lateral force equations (Figure 10.3).
Why do we scale base shear?
The requirement of a base shear scaling for the Response Spectrum Analysis (RSA) procedure is included in the building codes as a means to ensure that the minimum strength of a structure designed using the RSA procedure is similar to the strength that would be required if the structure was designed using the Equivalent …
What is base shear in Etabs?
1. MATCHING BASE SHEAR IN ETABS 2016 Base shear is an estimate of the maximum expected lateral force that will occur due to seismic ground motion at the base of a structure.
What is meant by response spectrum?
A response spectrum is a plot of the peak or steady-state response (displacement, velocity or acceleration) of a series of oscillators of varying natural frequency, that are forced into motion by the same base vibration or shock.
What is the difference between base shear and storey shear?
Base shear is an estimate of the maximum expected lateral force that will occur due to seismic ground motion at the base of a structure. Storey shear factor is the ratio of the story shear force when story collapse occurs to the story shear force when total collapse occurs.
What is the purpose of response spectrum?
Response spectra are very useful tools of earthquake engineering for analyzing the performance of structures and equipment in earthquakes, since many behave principally as simple oscillators (also known as single degree of freedom systems).
What is the purpose of response spectrum analysis?
Response spectrum analysis is a method to estimate the structural response to short, nondeterministic, transient dynamic events. Examples of such events are earthquakes and shocks.
Why do we use response spectrum?
Response spectra thus helps in obtaining the peak structural responses under linear range, which can be used for obtaining lateral forces developed in structure due to earthquake thus facilitates in earthquake-resistant design of structures.
How to balance static and spectral seismic base shear in ETABS?
To balance the static and the spectral seismic base shear, which is in other words, is to have a spectral base shear emanating from the response spectrum analysis at a certain percentage of the base shear derived from the static base shear equation. And how to actually do this in ETABS.
How to scale the response spectrum in ETABS?
If you are scaling the response spectrum to match with the static analysis results, you need to input the computed scale factor and specified it under response spectrum cases in ETABS. This is to convert the spectrum into required units and for the base shear to scale it to an appropriate level.
Why do we need to scale base shear results from dynamic analysis?
In the previous article, Scaling of Base Shear Results of Static and Dynamic Analysis we have learned about the principle why do we need to scale the base shear results obtain from dynamic analysis to reduce or match of the base shear results that is determined from the static force procedure.
What are the base shear requirements for ubc-97 and ASCE 7-05?
UBC-97 and ASCE 7-05 or later require that the base shear calculated using modal response spectrum dynamic analysis should exceed or match a certain percentage of the static base shear calculated using Equivalent Lateral Force procedure (static analysis). The requirements of ASCE 7-05 are implemented in this example.