基于岩土强度参数空间变异性的边坡强震稳定性的概率密度演化研究

According to the demand for seismic landslide prevention in seismic fortification areas of China, considering the spatial random variability of slope geotechnical parameters, this project conducts nonlinear dynamic reliability analysis of the anisotropic random field slope. Aims at the coupling characteristics of randomness and nonlinearity of the rock and soil parameters of slope subjected to the seismic ground motion, in light of theoretical analysis, numerical simulation, laboratory dynamic test and centrifuge test and other advanced research methods, and based on the research about the probabilistic complete representation of spatial variability of geotechnical parameters. And then, based on the probability density evolution method, combined with finite element nonlinear dynamic time history analysis, the project attempts to establish the nonlinear stochastic seismic response and seismic reliability analysis method of slope, and grasp the seismic stability slope from the angle of probability density evolution and nonlinear dynamic reliability theory. Finally, based on Monte Carlo stochastic simulation and centrifuge shaking table test, we confirm and check the validation of the nonlinear stochastic seismic response analysis method of slope built by this project. It provides a powerful scientific basis and reference for the dynamic stability assessment of slopes in strong earthquake areas in China, and has important scientific theoretical value and broad prospects for engineering application.

本项目根据我国广大抗震设防地区地震滑坡灾害防治需求，考虑边坡岩土参数的空间变异性，开展各向异性随机场边坡强震非线性动力可靠度分析研究。针对地震动力作用下边坡岩土参数随机性与非线性的相互耦合特征，综合采用理论分析、数值模拟、室内土动力试验以及离心机振动台试验等先进研究手段，研究边坡岩土参数空间变形异性的概率完备表达。在此基础上，基于概率密度演化理论，结合有限元非线性动力时程分析，建立边坡非线性随机地震动力响应与抗震稳定可靠性分析方法，从概率密度演化和非线性动力可靠度角度把握边坡的地震动力稳定性。最后，基于Monte Carlo随机模拟和离心机振动台试验验证与确认本项目所建立的边坡非线性随机地震动力响应分析方法的有效性。为我国强震区域的边坡灾害动力稳定性评估提供有力的理论依据与参考，具有重要的科学理论价值和广阔的工程应用前景。

近年来，全球进入地震活跃期，强震滑坡灾害往往会造成重大人员伤亡和财产损失，严重威胁区域生命线工程等基础设施安全。地震滑坡灾害防治的重要前提是准确把握边坡在地震作用下的动力响应，而岩土空间变异性严重影响边坡地震动力响应预测。为考虑岩土参数不确定性的影响，本项目围绕“岩土强度参数空间变异性导致边坡强震稳定性的概率密度演化”这一关键科学问题，交叉融合地质工程学、数理科学、地震工程学和随机动力学等多学科综合理论。采用理论推导、数值分析和模型试验等主要研究手段，顺利完成各项研究目标，表征了岩土参数空间变异性，构建了考虑岩土参数空间变异性的边坡非线性随机地震动力响应分析方法。相关研究成果在国际高水平期刊上发表SCI论文8篇，英文专著2部，此外，项目责人获得其他科研奖励一项。本项目研究成果可为地震滑坡灾害防治和边坡工程抗震设计与评估提供了科学参考和理论依据。