Why the Location of Center of Rigidity Changes for Each Story Even for Symmetric Structures?
Question: Why the Location of Center of Rigidity Changes for Each Story Even for Symmetric Structures? Answer: The center of rigidity is the center of resistance of a floor or diaphragm against lateral forces. It is the stiffness centroid located [...]
The Definition of Design Basis Earthquake Level and the Retrofit Need for Structures Designed for Older Codes
Question: I noticed that with the updates of codes it seems that with the passage of time the seismic parameters (response spectral accelerations) are increasing. For example if we compare earlier versions of AASHTO (if we talk about bridges) and the [...]
Why building codes require a base shear scaling for the RSA procedure?
Question: Why in different building codes (UBC 97 or ASCE 7) the results of Response Spectrum Analysis (RSA) should be scaled such that the design base shear should match with the (e.g. 80%, 90% or 100% of the) design base shear [...]
Torsional Irregularity Check and Accidental Torsion
Question: I am currently working in a Consultancy firm in Islamabad and have few queries regarding torsional Irregularity explained as follows: 1) As per UBC torsional irregularity exists if "Maximum story drift, computed including accidental torsion, at one end of [...]
Why the Location of Center of Rigidity Changes for Each Story Even for Symmetric Structures?
Question: Why the Location of Center of Rigidity Changes for Each Story Even for Symmetric Structures? Answer: The center of rigidity is the center of resistance of a floor or diaphragm against lateral forces. It is the stiffness centroid located [...]
The Definition of Design Basis Earthquake Level and the Retrofit Need for Structures Designed for Older Codes
Question: I noticed that with the updates of codes it seems that with the passage of time the seismic parameters (response spectral accelerations) are increasing. For example if we compare earlier versions of AASHTO (if we talk about bridges) and the [...]
Why building codes require a base shear scaling for the RSA procedure?
Question: Why in different building codes (UBC 97 or ASCE 7) the results of Response Spectrum Analysis (RSA) should be scaled such that the design base shear should match with the (e.g. 80%, 90% or 100% of the) design base shear [...]
Torsional Irregularity Check and Accidental Torsion
Question: I am currently working in a Consultancy firm in Islamabad and have few queries regarding torsional Irregularity explained as follows: 1) As per UBC torsional irregularity exists if "Maximum story drift, computed including accidental torsion, at one end of [...]