Optimum Seismic-Resistant Design of R/C Frames

The procedure is based on a computer-aided iterative technique. It consists of two main phases: (1)A preliminary design phase, which is repeated until an acceptable preliminary design is obtained; and (2)a final design phase. Seismic design forces are found from an inelastic design spectrum employing a modal analysis technique. A weak-girder strong column design criterion is imposed and member design is based on a story-wise optimization procedure using a linear programming technique. Once a design is obtained, a series of linear and nonlinear structural analyses are carried out to evaluate in the preliminary design phase, the acceptability of the design, and in the final design phase, the reliability of this design. Two designs obtained by employing the optimization procedure and a design based on UBC seismic forces and conforming to the requirements of this code are compared with respect to volume of material required and to response characteristics. The use of computers allows alternate designs to be rapidly and economically formulated and evaluated.