摘要
在结构体系可靠度研究的基础上,根据水闸的工作特点,对服役水闸的体系可靠度计算方法进行了探讨,并分析了建于软基上的水闸闸室的体系可靠度,对水闸闸室的安全性进行了评价。软基上的水闸可看成由4种主要失效模式(沿闸基面的滑动、下游闸趾压坏、上游闸踵拉裂和上下游应力不均匀)所组成的串联体系。通过工程实例,建立了水闸极限状态功能函数,运用Monte-carlo法求得对应的可靠性指标与失效概率;并用常用的体系可靠度计算方法得到水闸体系可靠度和失效概率。由计算结果看出,水闸闸室沿闸基面滑动为水闸的最主要失效模式,上下游应力不均匀、上游闸踵拉裂、下游闸趾压坏为次要失效模式。可采取相应措施来提高水闸的抗滑稳定性。另外,某些变量的随机特性对失效模式的可靠性指标影响甚大,变量摩擦系数、粘聚力为影响水闸稳定的关键参数,而变量上下游水位则影响上下游应力的不均匀性。
Based on the reliability study of structure system and the characteristics of floodgate, the reliability calculation methods for system of the floodgate in use are discussed. Through calculating the system reliability of the gate chamber on soft foundation, its safety degree can be estimated more deeply. The floodgate may be regarded as a series system with four main failures modes including slip along the foundation, compression failure of the floodgate toe in the downstream line, tension crack of the floodgate heel in the upper stream and non-uniform stress distributions. Through the project example, the limit state equation of the floodgate was established, the failure probability and reliability index are obtained by the method of Monte-carlo. And system reliability and failure probability were calculated by common method. The results show that the four failure modes were ranked from highest to lowest effect： slip along the foundation, non-uniform distributions of stress, tension crack of the floodgate heel in the upper stream and compression failure of the floodgate toe in the downstream line. Besides, some relevant measures can be taken to raise the stability of the floodgate. The random property of some variables are affected the reliability index of the failure mode, for instance, the main influencing factors to stability are friction factor and angle of internal friction of foundation,and the non-uniform distributions of stress is affected by the upstream and downstream water levels.
出处
《排灌机械》
2006年第2期16-19,共4页
Drainage and Irrigation Machinery
基金
浙江省水利厅供水系统建筑物风险分析基金项目(RC0419)
关键词
水闸闸室
体系可靠度
失效模式
可靠指标
失效概率
Gate chamber
System reliability
Failure mode
Reliability index
Failure probability
