关键词: 重力坝;变形安全;多级预警;最大熵;预警概率;层次分析法;棉花滩水电站;

Abstract: It is extremely important to formulate accurate and reasonable deformation safety early-warning indicators based on the deformation monitoring information of dams，so as to ensure the safety state.However，the conventional method of determining the deformation safety early-warning index of concrete gravity dams is prone to be affected by the randomness of deformation samples and the subjectivity of failure probability.Aiming at this disadvantage，a determination method of deformation samples distribution function based on the maximum entropy theory was discussed.A probability determination method of the safety early-warning of gravity dams deformation that represents different service statuses was established by integrating analytic hierarchy process and particle swarm optimization algorithm.Based on this，a method of determining multi-level safety early-warning index of gravity dams deformation considering the change of service status was put forward.The calculation results of a project example show that the first-level，second-level and third-level warning indexes of horizontal deformation safety of dam crest to the downstream direction of No.5 dam section are 5.88 mm，6.89 mm and 7.79 mm respectively，which are in good agreement with the results of structural analysis method，proving the effectiveness and feasibility of this method.

Key words: gravity dam；deformation safety；multi-level early-warning；maximum entropy；early-warning probability；analytic hierarchy process；Mianhuatan Hydropower Station