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The performance-based seismic engineering (PBSE) produces structures with predictable seismic performance. This approach is not new. Using this approach / model Turbine, Airplanes & Automobiles are made. In these applications one or more prototype are built and subjected to extensive testing. To incorporate the lessons learned from the experimental evaluations the design and manufacturing process is then revised, once the cycle of design, prototype manufacturing, testing and redesign is successfully completed, the product is manufactured in a massive scale.
In the automotive industry, for example, millions of automobiles which are virtually identical in their mechanical characteristics are produced following each performance-based design exercise.
Performance Based Earthquake Engineering/Design is not that popular because the scale of output is not large in comparison to the Automobile industry and others. Each building designed by this process is virtually unique and the experience obtained is not directly transferable to buildings of other types, sizes, and performance objectives. Therefore, up to now PBSE has not been an economically feasible alternative to conventional prescriptive code design practices. In coming few years we can say that Performance Based Design will become the standard method of delivering Earth Quake resistant designs.
The facts are clear – We cannot prevent big, destructive earthquakes from occurring. These pose a continuing threat to lives and property in more than 55% of the area of this country. However, it is possible to avoid the disastrous consequences of an earthquake and that precisely is the objective of every seismic design code practice.
The seismic codes are framed primarily with the objective of prevention of loss of life. In order to meet this objective it is essential that the structures/constructed facilities respond to the expected earthquake ground motions at the site in a designated manner, which in turn depends on the nature of ground motion exciting the structure.
Thus the reliability of achieving the life safety performance objective of any constructed facility is governed by the most uncertain element in the chain- expected ground motion.
Seismic hazard and Damage state are the two essential parts of a Performance objective. Seismic performance is described by designating the maximum allowable damage state (performance level) for an identified seismic hazard (earthquake ground motion). The target Performance level is split into two levels Non-structural damage and Structural damage, the combination of the two gives the building a combined performance level.
