Dynamic Analysis of Base Isolated Method Structures with Equivalent SDOF oscilator

In this Paper, after a brief descreption of structural base isolation technique to reduce the destructive earthquake effects a simple method for dynamic analysis of these structures is presented. Here; the isolated structure is replaced by a SDCF oscillator . so that spectrum analysis may be easily applied.
Although this method is based on having the same spectrum responses for real and equivalent systems, it ','ill be seen that their time history responses are also
identical. This is a useful tool that makes the designer to decide whether to use the base isolator for speciefied structure and is more important that with this technique, the psedu static analysis of structures for earthquake loads, can be replaced by a simple, exact and practical spectrum analysis.