LOCATING CONCENTRATED SEEPAGE PIPES IN DAM WITH TEMPERATURE GLOBAL OPTIMIZATION

This paper is to decrease the tentative calculations and get the global optimum in higher possibility. The temperature global optimization is employed to locate the concentrated seepage pipes in rock-soil body of the dam or abutment. Global search(GS), Multistart(MS) and Genetic algorithm(GA) are selected to estimate the positions of the concentrated seepage pipes with the discontinuous objective function associated with cooperation and complementarity of these algorithms. Firstly, the local optima are searched by GS.Then in the consequent MS optimization, the local optima are inputted as the initial starts to increase the probability of searching the global optima. Finally, the result is verified or improved by genetic algorithm and its hybrid algorithm. According to the characteristics of concentrated leakage passage recharged by water in lower temperature, the objective function in the optimization is modified with this specific physical meaning. The step-by-step optimization is set up to reduce the parameter amount in each iteration. The number of the concentrated seepage pipes is ascertained by the attraction basins composed by temperature datum or their residuals. The optimization is terminated when the modified residual is less than the data detection precision. The real solution for the locations of the concentrated passages is the iteration result with the least residual. In the case study, two intense concentrated seepage pipes and three minor ones are estimated by step-by-step and direct optimizations in the left leaky dam abutment of Douhe reservoir, where the locations of the multi-seepages are firmed by engineering practice partly.