RELIABILITY ANALYSIS OF R.C.C. BUILDING FRAMES

Abstract

When an engineering structure is loaded in some way it will-, res-pond in a manner which depends upon the type and magnitude of load and strength and stiffness of structure. Whether the response is conside-red satisfactory depends upon certain limit states. The violation of a limit state is an undesirable condition for structure. The study of structural reliability is concerned with the calculation and predicti-on of probability of.lirnit state violation. The present study is an attempt to give a technique for reliability analysis of frames using stiffness matrix method of linear elastic and piecewise linear elasti-c-plastic analysis and the first order second-moment reliability meth-od. It involves automatic generation of stochasatically dominant mec-hanism and their safety margin equations and calculations of bounds on the system reliability. In case of reinforced concrete frames any critical section, hinged earlier, may fail due to insufficient plastic rotation capacity before a collapse mechanism is formed. Here limited plastic rotation capacity is considered in verifying and analyzing the identified dominant mechanisms and it is considered in generating rot-ation failure modes. The rotation failure mechanism is then combined with other possible mechanism to assess the system reliability of a RCC frame. The generalized computer program in C language is develop-ed for computing the reliability for simple frame. Typical example of a frame is taken. A number of parameters like moment of resistance, dead load and live load, rotational capacity, flexural rigidity etc. were varied with a view to study the effect on reliability. The resu-lts are presented and critically discussed.