受损拱坝的震后承灾能力及安全评价研究

Arch dam may suffer from severe damage under the earthquake action greater than design earthquake due to the uncertainty of earthquake, and the reservoir slope may also suffer from earthquake damage and the capacity to resist heavy rainfall and aftershocks may decrease and lead to slope failure which can cause reservoirwater fluctuation. The earthquake-damaged arch dam may be faced with the threats of dynamic reservoir water impact and aftershocks. The capacity against secondary disaster and post-earthquake safety evaluation for earthquake-damaged arch dam would be studied, including: (1) SPH-based phase transforming method and SPH-FEM-based reservoir-arch dam dynamic interacton analysis method for reservoir water impact action and the program validation; (2) theoretical solution of slope failure-induced reservoir water impact wave and analytical study of characteristics of dynamic pressure on upper face of arch dam; (3) study of the effect of influence factors on impact pressure on arch dam surface and study of equivalent load model;(4) study of capacity against slope-induced reservoir water impact on different degree of earthquake-damaged arch dam and the correlation of the water-impact resisting capacity with earthquake damage;(5)study of the evaluation index of disaster-resisting performance of earthquake-damaged arch dam，engineering measures and the modal test valiadation.The research would offer theoretical bases and scientical foundation for reasonable post-earthquake evalutation of post-earthquake anti-disaster capacity and safety performance of earthquake damaged arch dams.

地震动的强烈不确定性使得混凝土坝存在遭受超设计地震动的可能性而受到较大的损伤破坏，库区边坡在强震作用下同样由于损伤破坏造成抵御暴雨或强余震的能力降低而失稳引发库水波动，从而受损拱坝震后面临着强余震和库水冲击的威胁。本项目针对强震中受损拱坝的震后承灾能力及安全开展研究,包括:(1) 基于SPH的相变转换方法和库水冲击作用下基于SPH-FEM耦合的库水-大坝动力相互作用分析方法及程序验证; (2)滑坡激发库水冲击压力的理论研究及坝面冲击压力荷载特征研究；(3)坝面冲击压力的时间和空间分布特征的影响因素研究及等效荷载模型研究;(4)遭受不同强度地震的震损拱坝对滑坡诱发库水冲击作用的承载能力及其与震损指标间的相关性;(5)震损拱坝的震后抗灾安全性能评价指标、安全措施及模型试验验证研究。通过以上研究，为合理评价灾后震损拱坝的震后承载能力及安全评估提供理论基础和科学依据。

受损拱坝的震后承灾能力及安全评价研究与拱坝的地震破坏机理、滑坡涌浪的数值模型、库水-拱坝动力作用耦合方法和震损拱坝承灾能力评价指标等环节密切相关。当前由于滑坡涌浪数值方法、库水-拱坝动力相互作用等效分析模型和拱坝承灾能力评价指标等等方面的研究不足，严重制约了不同地震强度的震损拱坝在库水冲击下的动力损伤特性的研究。因此，综合理论分析、数值模型和模型试验三种方法，开展库区滑坡冲击作用下库水冲击的理论研究，提出滑坡涌浪及库水-拱坝耦合数值程序。在此基上研究不同情况下滑坡涌浪冲击压力的时间和空间分布特征、影响因素，提出等效荷载模型及流体-拱坝动力相互作用等效模型。随后，深入研究不同强度地震作用下的震损拱坝对滑坡引发库水冲击作用下的动力损伤演化规律、承载能力及影响因素。最后，提出震损拱坝库水冲击压力抗灾性能评价指标、极限承载力评价标准及应急工程措施，为受损拱坝在震后短时间内得到维修预警信息和灾害损失预估具有重要工程实践价值，为拱坝在全寿命周期内的安全运行和承载力评价起到保驾护航的作用。