Abstract

The reliability analysis is one of the main methods for the quantitative analysis of the safety in the geotechnical engineering. This method can provide the failure probability with a clear physical meaning. Due to the complex structure of high earth-rock dams and the non-linear characteristics of the material properties, it is very difficult to perform the reliability analysis on such large nonlinear structures. Currently, there are few studies on the reliability analysis of high earth-rock dams that consider the earthquakes, the dam body deformation and the dam slope stability at the same time. In this paper, the dam cracks generated by the earthquakes are used as the criteria for the dam body seismic deformation evaluation, and the inclination method is adopted for the dam body seismic deformation analysis. The simplified Bishop method combined with the ratio of the safety margin method is used to analyze the dam slope stability. In order to consider the soil material properties, the thickness of the compressible soil layer and the uncertainty of the earthquakes, a seismic failure probability analysis method for evaluating the seismic danger of high earth-rock dams considering the dam body deformation and the dam slope stability is established based on the reliability theory. Taking a concrete face rockfill dam as an example, the method is used to analyze the seismic failure probability of the dam during the design reference period. It provides the reference for the seismic design and the risk analysis, and establishes the risk level of high earth-rock dams.

摘要

可靠性分析是岩土工程安全性定量分析的主要方法之一。这种方法可以提供具有明确物理意义的失效概率。由于高土石坝结构复杂，材料特性具有非线性特性，对此类大型非线性结构进行可靠性分析非常困难。目前，同时考虑地震、坝体变形和坝坡稳定性的高土石坝可靠性分析研究较少。本文以地震产生的坝体裂缝作为坝体地震变形评价标准，采用倾角法进行坝体地震变形分析。采用简化Bishop法结合安全裕度比法对大坝边坡稳定性进行分析。为综合考虑土体材料性质、可压缩土层厚度和地震的不确定性，提出考虑坝体变形和坝坡稳定性的高土石坝地震危险性评价地震破坏概率分析方法建立在可靠性理论的基础上。以某混凝土面板堆石坝为例，采用该方法对设计基准期内大坝的地震破坏概率进行分析。为抗震设计和风险分析提供参考，确立高土石坝的风险等级。为综合考虑土体材料性质、可压缩土层厚度和地震的不确定性，提出考虑坝体变形和坝坡稳定性的高土石坝地震危险性评价地震破坏概率分析方法建立在可靠性理论的基础上。以某混凝土面板堆石坝为例，采用该方法对设计基准期内大坝的地震破坏概率进行分析。为抗震设计和风险分析提供参考，确立高土石坝的风险等级。为综合考虑土体材料性质、可压缩土层厚度和地震的不确定性，提出考虑坝体变形和坝坡稳定性的高土石坝地震危险性评价地震破坏概率分析方法建立在可靠性理论的基础上。以某混凝土面板堆石坝为例，采用该方法对设计基准期内大坝的地震破坏概率进行分析。为抗震设计和风险分析提供参考，确立高土石坝的风险等级。基于可靠度理论，建立了考虑坝体变形和坝坡稳定性的高土石坝地震危险性评价地震破坏概率分析方法。以某混凝土面板堆石坝为例，采用该方法对设计基准期内大坝的地震破坏概率进行分析。为抗震设计和风险分析提供参考，确立高土石坝的风险等级。基于可靠度理论，建立了考虑坝体变形和坝坡稳定性的高土石坝地震危险性评价地震破坏概率分析方法。以某混凝土面板堆石坝为例，采用该方法对设计基准期内大坝的地震破坏概率进行分析。为抗震设计和风险分析提供参考，确立高土石坝的风险等级。