Tentative Application of Computer Simulation Technique to the Risk Evaluation of Large Concrete Dams

Failure probability calculation is the scientific basis for the quantitative analysis of large dam risk and thus, probing the method of calculating large dams´ failure probability is of considerable scientific significance and is urgently required by engineering application. While risk evaluation is required for individual large dams, no country can afford the failure calamity test on actual large dams in view of the vast investment in the large dam construction, and it is only possible to reveal the mechanism of the failure by means of computer simulation of process of failure occurrence, on the basis of both indoor model experiment and large-dam operation monitoring data. At present, in the field of large dam engineering, JC method and Monte Carlo method are generally recommended for the quantitative calculation of the failure probability. Due to the complexity of large dams´ structure and their boundary conditions, the randomicity of the load and resistance force and the fact that there exists no analytic expression between the output and input quantities but the usual implicit function, the calculating of large dam´s failure probability by means of JC method or Monte Carlo method cannot do without computer numerical simulation to some extent. A tentative approach is made in making use of computer simulation technique to generate the random number of random variables of both the load and the resistance force, to establish the state function of the failure modes and to conduct independent transformation of relevant random variables. Based on the computer simulation results, the failure probability of a large dam is calculated out by means of JC method and Monte Carlo method respectively.