In my ETABS model, the first mode appears as a torsional mode. The structure is symmetric in both directions. There are two opposing U-shaped shear walls located at the center of the building, connected by a coupling beam. What could be the reason for the first mode being torsional?
While defining the response spectrum in ETABS for(TSC 2018), the program directly creates the reduced design spectrum when defining the horizontal spectrum function. In this case, when defining the seismic loads using a modal combination method, is it necessary to divide the gravitational...
While defining the response spectrum in ETABS for(TSC 2018), the program directly creates the reduced design spectrum when defining the horizontal spectrum function. In this case, when defining the seismic loads using a modal combination method, is it necessary to divide the gravitational...