Improved Code‐Type Earthquake Analysis Procedure for Buildings

Based on the limitations of present building code formulas for earthquake forces identified in an earlier paper, an improved procedure to estimate the earthquake forces for the initial, preliminary design of buildings is presented. Starting with the earthquake design spectrum for elastic or inelastic design and only the overall, general description of the proposed building, this procedure provides an indirect approach to estimate the response in the first two vibration modes of the building. The procedure recognizes the important influence of those building properties and parameters that significantly influence its earthquake response without requiring all the computations inherent in standard dynamic analysis by the response spectrum method. The procedure represents a major improvement over present building codes with little increase in computational effort.