基于波浪冲刷的现有堤坝护坡破坏的风险分析

Analysis on risk from revetment failure of existing dikes or earth-rock dams based on wave cut

基于可靠性及风险分析的基本概念,根据设计规范中对堤坝上游护坡厚度的要求,建立了堤坝上游护坡抵抗波浪冲刷破坏时的风险分析模型,分析了抵抗波浪冲刷破坏的极限状态;根据建立的极限状态方程,分析了其中的广义荷载效应和广义承载力,并提出了基于设计规范的现有堤坝上游护坡波浪冲刷破坏的风险分析方法.计算结果表明,提出的风险计算方法可行,能有效地分析现有堤坝上游护坡在波浪冲刷下的破坏概率,并可分析其中基本变量的随机性对护坡波浪冲刷破坏风险率的影响.根据该方法,可较简便地实现现有堤坝上游护坡抵抗波浪冲刷的风险率计算,并为现有堤坝的整体可靠性评价分析和上游护坡的设计及计算提供了一种简便的方法.

Based on the basic concept of reliability and risk analysis and the requirement of thickness of upriver revetment of dikes or earth-rock dams from the Chinese design standard, a model of risk analysis for resistance to wave cut at upriver revetment of dikes or earth-rock dams is proposed, and the limit state of wave cut failure is also analysed. Based on the built limit state equation, the generalized load effect and generalized resistance are studied. Analysis method of failure risk due to wave cut to upriver revetment of the existing dikes or earth-rock dams is proposed based on the Chinese design standard. It is indicated that the proposed method is workable and it can analyse effectively failure probability of upriver revetment of the existing dikes or earth-rock dams under wave cut, and the method can also analyse the influence of randomness of the basic variables on failure risk probability of wave cut for upriver revetment. According to the method, it is easy and simple to calculate for the failure risk probability of wave cut for upriver revetment of the existing dikes or earth-rock dams, and it is also simple to evaluate the whole reliability of the existing dikes or earth-rock dams and to calculate for design of their upriver revetment.