EVALUATION OF THE TIME-DEPENDENT EFFECTS ON SEISMIC PERFORMANCE OF HIGH-RISE BUILDINGS WITH DIFFERENT STRUCTURAL SYSTEMS

Practical experiences has shown that structures can be subjected to very large deformations due to creep and shrinkage; the consequences are excessive deflections of the structural members, wide cracks in the tension zone of the concrete and redistribution of stresses in statistically indeterminate structures. To have a reasonable and economic design, having some information about the initial condition of the structure is very important because different primitive states can change the seismic analysis results and may cause some problems to satisfy prescribed limits of deformations and strengths. So, having a real seismic design should be accompanied by considering the time-dependent behavior and its effects on structural and nonstructural members as an initial condition. This paper contains the results of the sensitivity analyses which are performed on buildings with different structural systems in elevation or plan to find particular characteristics which made structures to be more sensitive to additional considerations. Also it is tried to mention some critical weak points of each structural system due to analyses results.