Development of dike fragility curves for piping and micro-instability breach mechanisms
Development of dike fragility curves for piping and micro-instability breach mechanisms
复制标题
开发管道和微失稳溃口机制的堤坝脆弱性曲线
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
H. Apel
中科院分区：
文献类型：
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作者：
S. Vorogushyn;B. Merz;H. Apel
抽象的。本文分析了目前河堤溃决的机制。堤坝基础中的管道和由于渗流穿过堤坝核心（微观不稳定）而导致的边坡破坏被认为是历史上建造的堤坝的两种主要溃口机制，以及漫溢和边坡宏观不稳定。对于前两种机制，对基于物理和经验的过程描述进行了审查，并导致了可靠性函数的制定。在蒙特卡罗框架中对这些函数针对时间相关载荷的评估导致了脆弱性函数的发展。这些函数表示加载时堤坝部分失效的概率，并且可以针对每个空间离散的堤坝部分进行计算。溃决的概率取决于堤坝几何和岩土参数的不确定性。在蒙特卡罗模拟中计算脆弱性函数时，明确考虑了这种不确定性。进行敏感性分析，以确定影响失效概率分布的敏感岩土参数。敏感参数的识别表明了旨在评估堤坝稳定性的岩土测量活动的优先顺序。新开发的脆弱性函数可应用于洪水灾害和风险评估研究，以在概率框架中对堤坝破坏进行建模。
Abstract. The paper analyses the prevailing breach mechanisms of fluvial dikes. Piping in the dike foundation and slope failure as a consequence of seepage flow through a dike core (micro-instability) were identified as two of the dominant breach mechanisms for historically-grown dikes along with overtopping and slope macro-instability. For the former two mechanisms the physically-based and empirical process descriptions were reviewed and led to the formulation of the reliability functions. Evaluation of these functions in the Monte Carlo framework for the time dependent load led to the development of fragility functions. These functions indicate the probability of failure of a dike section upon loading and can be computed for each spatially discretised dike section. The probability of breaching is conditioned by the uncertainty in geometrical and geotechnical dike parameters. This uncertainty is explicitly taken into account during computation of the fragility functions in a Monte Carlo simulation. Sensitivity analysis was carried out in order to identify the sensitive geotechnical parameters influencing the distribution of failure probability. The identification of sensitive parameters indicates the priorities in geotechnical measurement campaigns aimed at the assessment of dike stability. The newly developed fragility functions can be applied in flood hazard and risk assessment studies for modelling of dike failures in a probabilistic framework.