混凝土坝运行期安全评估与全坝全过程有限元仿真分析

混凝土坝仪器观测提供的变位、温度、扬压力等资料,对于监控大坝工作状态是有用的,但它们不能给出大坝安全系数.混凝土坝实际应力场十分复杂,应变计测点太少,即使应变观测资料全部有效,也不能给出坝体应力场全貌和安全系数,何况由于种种原因,应变计观测资料实际可利用率并不高.在运行期,每隔一定时间需对坝体进行一次安全评估,目前主要采用设计规范中规定的计算方法求安全系数,如材料力学方法、拱梁分载法、刚体极限平衡法等,这些都是七八十年以前的老方法,施工期和运行期所积累的丰富资料在计算中难以反映,建议采用全坝全过程有限元仿真方法计算运行期坝体安全系数,可以较好地反映混凝土坝实际安全状态.

Whole dam and whole course finite element simulation method for safety appraisal of concrete dams

The stress state of concrete dam in the operation period is very complicated while the points of stress-strain observation are very few, thus the safety factor of the dam can not be obtained from the observation resuhs of strain meters. Practically, the safety factors of concrete dam in the operation period are given by computation method stipulated in the design specifications which were developed before 1940. The abundant data accumulated in the period of construction and operation can not be reflected in the computation by these old methods. It is suggested to use the whole dam and whole course finite element simulation method to compute the safety factors in the safety appraisal of concrete dams in the operation period.