ETABS Tutorial 11: Defining Load Combinations with RSA Earthquake Loads and Scaling Factors

This video shows how to define load combinations in ETABS software using the earthquake loads of the Response Spectrum Analysis (RSA) method. Additionally, it provides guidance on calculating the scaling factor (SF) used to adjust the RSA-reduced demand. Here's a summary of the steps: Step 1: Define RSA (Response Spectrum Analysis) Load Case Create a load case in ETABS with a "g" unit to represent the RSA. Step 2: Multiply RSA Demand Forces by I/R (ASCE 7-10) Create a load combination called "Reduced RSA". In this load combination, multiply the RSA demand forces by I/R (where I is the importance factor, and R is the response modification factor). Step 3: Compute the Scaling Factor (SF) Compute the scaling factor (SF) according to ASCE 7-10. The formula for SF is 0.85Velf/Vt, where "Velf" is the base shear from the Equivalent Lateral Force procedure, and "Vt" is the reduced base shear from the RSA method. Step 4: Obtain RSA Design Demands Create a load combination called "Internal forces. In this load combination, calculate the RSA design demands by multiplying the Reduced RSA forces (from Step 2) by the scaling factor (SF) obtained in Step 3. The formula for RSA design demands is Internal forces = Reduced RSA x SF. 0:00 Intro + Defining "RSA" Load Case 2:11 ASCE Requirements of RSA Method 4:23 Defining Load Combinations 7:48 Computing the Scaling Factor You can access and download the Excel sheets by clicking on the link below: https://drive.google.com/drive/folder...