基于实测资料反馈的降雨诱发滑坡数值模拟与稳定性预测方法

The stability evaluation and prediction of rainfall-induced landslides is quite significant since the disasters often cause huge loss of life and property. Traditional slope stability prediction methods based on mathematical or statistical theories are of less universality and extrapolation ability. Unsaturated elastoplastic numerical simulation analysis method with monitoring data feedback holds the advantages that it could reveal the slope geotechnical characteristics and geological structure of individual differences. However, major factors restricting the simulation and prediction accuracy of the method are the choosing rationality of the unsaturated elastoplastic constitutive model, the parameters estimating accuracy of the aforementioned model and the derivation validity of the forecast criterion. On the basis of our previous work and regarding the in-depth analysis of unsaturated soil physical and mechanical properties as the starting point, numerical simulation and stability prediction method of rainfall-induced landslide based on feedback analysis of monitoring data will be set up through establishing of unsaturated elastoplastic constitutive model, verification testing of homogeneous soil slopes under rainfall infiltration, mutual feedback mechanism forming of rainfall driving force- displacement response - plastic strain region expansion, identifying and optimizing of dominated parameters considering stage evolution characteristics of slope and simulating of rainfall-induced landslides with feedback analysis. The proposed method has great value and can provide substantial theoretical basis for safety monitoring and early warning of important slope.

降雨诱发滑坡常导致巨大的生命财产损失，其稳定性评价与预测意义重大。仅靠数学或统计学推演得到的传统预测模型普适性较差，外推适应性程度低。基于监测信息反馈的非饱和弹塑性数值模拟分析方法具有揭示边坡岩土特性及地质结构等个体差异、预测降雨诱发滑坡稳定性的优点，但在其分析过程中，弹塑性非饱和土本构模型选择的合理性、模型参数估值的准确性、预报判据推导的有效性将制约其数值模拟与监测预报的精度。本课题拟在项目组已有研究成果基础上，以深入分析非饱和土的物理力学特性为出发点，通过非饱和土弹塑性本构模型建立、降雨入渗条件下均质土坡模型试验验证、降雨荷载驱动-边坡位移响应-土体塑性应变区扩展的三元互馈机制构建、考虑滑坡阶段演化特征的主控参数优化辨识、降雨诱发滑坡过程数值反馈分析等研究，建立基于观测资料反馈的降雨诱发滑坡数值模拟与稳定性预测方法。该方法可为重要边坡的安全监测与预警提供理论依据，具有较大的应用价值。

降雨诱发滑坡的失稳机理是边坡防治与减灾研究中的核心基础，但由于孕灾环境的多变性和复杂性，其致灾机理及滑坡演化过程的数值模拟仍需深入研究。本课题拟在项目组已有研究的基础上，以深入分析非饱和土的力学特性为出发点，通过非饱和土弹塑性本构模型建立、均质土坡模型试验及降雨诱发滑坡过程数值模拟等研究，揭示降雨入渗与边坡结构的耦合作用机理，并验证所建本构模型的合理性及有效性，从而建立一个基于广义塑性力学考虑降雨入渗条件下的边坡稳定性反馈分析方法。研究成果将为边坡的防灾减灾工程措施应用及其安全监测与预警提供理论依据和技术支撑。通过本项目研究，提交《基于实测资料反馈的降雨诱发滑坡数值模拟与稳定性预测方法》报告1份，发表论文14篇，撰写专著2部，授权发明专利1项，软件著作权3项，培养硕士研究生与技术骨干共3人。项目主要研究成果已应用于云南龙江水电站工程近坝岸坡的监测预警中，并取得显著成效。