Abstract：The fundamental features of the landslide BIII2 with expansive soil and soft rock，occurring in water supply reconstruction projection from Dongjiang to Shenzhen, is analyzed in this paper. Some important issues of reinforcing design with prestressed anchor cables are discussed. The bearing force characteristic of prestressed anchor cables and the stability of the slope are analyzed according to the considered issues. The key factors that influence the design parameter are identified based on analysis of factors with application of theory of optimization and decision. The optimum value of design parameter is determined by optimal decision of the key factors. The optimum design of reinforcing project with prestressed anchor cables is given based on the analysis of sliding surface and the strength data. Finally the stability analysis of the BIII2 landslide shows that the reinforcing project is feasible and have played an important role in timely treatment of the landslide.
