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提出一种考虑能量-时间分布的边坡动力可靠性分析方法。该方法将动态最危险滑动面及其稳定系数以时间序列加以刻画,并根据边坡动力反应的能量分布特征,提取持续时间统计窗,用于对上述时间序列的统计分析,以获取边坡动力模糊失效概率、边坡动力可靠度指标和基于保证率的边坡动力稳定系数。以澳大利亚计算机应用协会边坡稳定考核题为例,应用上述新方法考察其在芦山7.0级主震波形条件下的稳定性,研究了在不同统计窗下的边坡动力可靠性。案例分析表明:(1)新方法能够抓住影响边坡动力稳定的主要时间段,使分析结果更为凝练、可信。(2)通过引入边坡失效状态的模糊判别,使得可靠性评价中能够考虑模糊性,解决了以往常规方法区分度不够的问题。(3)基于保证率的边坡动力稳定系数具有很好的应用前景,它在内涵上体现了可靠性分析,在形式上与静力稳定系数的定义兼容,在数值上反映了边坡瞬时动力稳定系数的保守估计值,在实践上与现行规范的拟静力法具有良好的可比性,因而具有多方面的优势。(4)就本案例而言,动力条件下最危险滑动面的发育位置趋向于静力条件下的最危险滑动面,体现了依据静力和拟静力理论框架所进行的防护工程设计,在动力条件下仍然具有积极的意义。(5)新方法对定量研究现行边坡规范的抗震设计冗余提供了一条途径。提出的新方法为边坡抗震研究提供了新的思路、方法和可供参考的实例。
A method to analyze slope dynamic reliability considering energy-time distribution is proposed. In this method, the most dangerous dynamic sliding surface and its stability coefficient are plotted in time series. Based on the energy distribution of the dynamic response of the slope, a statistical window of duration is extracted for the statistical analysis of the above time series to obtain the slope dynamic Fuzzy failure probability, dynamic reliability index of slope and slope stability coefficient based on guaranteed rate. Taking ASIA slope stability assessment as an example, this new method is applied to investigate the stability of slope stability at Lushan MS 7.0 and the reliability of slope under different statistical windows. Case studies show that: (1) The new method can seize the main time-period that affects the dynamic stability of slope and make the analysis more concise and credible. (2) By introducing the fuzzy judgment of the failure state of the slope, the fuzziness can be considered in the reliability evaluation, which solves the problem that the conventional method is not enough. (3) The stability factor of slope dynamic stability based on the guaranteed rate has a good application prospect, which reflects the connotation of the reliability analysis, is formally compatible with the definition of static stability coefficient and numerically reflects the transient power of the slope The conservative estimate of the stability coefficient has a good comparability with the quasi-static method of the current standard in practice and thus has many advantages. (4) For the present case, the development position of the most dangerous sliding surface under dynamic conditions tends to be the most dangerous sliding surface under static conditions, which reflects the design of protective engineering based on the theoretical framework of static and quasi-static forces. Dynamic conditions still have a positive meaning. (5) The new method provides a way to quantitatively study the seismic design redundancy of the existing slope codes. The new method proposed provides a new idea, method and reference for the study of slope seismic.