Abstract：Rock slope stability depends on the strength features of the rocks. Determination of the strength of rock masses is difficult since the size of representative specimens is too large for laboratory testing. This difficulty can be overcome by using the parameter identification procedures. The inverse problem of geotechnical parameters identification is treated as the optimization problem. The hybrid genetic algorithm is presented and used for the identification of the shear strength parameters of geotechnical materials according to the observed shape of slip surface of rock slope. Genetic algorithm(GA) is a powerful alternative to traditional optimization methods which are too restrictive. One of the main advantages of GA is that it requires no information about the objective function. In order to identify parameters efficiently and in a robust manner，the gradient search method and genetic algorithm are combined to produce an adaptive procedure that has the merits of the two methods. The validity and efficiency of the proposed procedure are shown by an example involving parameter identification. The results obtained are compared with earlier results obtained by other methods.
