Modified Harmony Methods for Slope Stability Problems

In many practical slope stability problems, a thin layer of soft material with very low shear strength parameters may exist. Such soft and thin soil layer has caused many large scale slope failures in Hong Kong and many other places. Determining the critical failure surface with the smallest factor of safety for such a problem is extremely difficult. This chapter proposes a domain transformation technique, which is coupled with two new versions of improved harmony search algorithms to ensure both the efficiency and effectiveness of optimization analysis for large scale difficulty problems. The improved harmony search algorithms differ from the original harmony search algorithm in that: (1) the harmonies are rearranged into several pairs and the better pairs are used to develop several new harmonies; (2) different probabilities are assigned to different harmonies. The robustness of the newly proposed methods is demonstrated by using some difficult slope stability problems, and the improvement in the efficiency of the new algorithms is examined with respect to some large scale slope stability problems in China.