基于参数空间变异性识别的碎石土斜坡降雨入渗稳定性研究

Gravel soil slopes are widely distributed in nature and often destabilize during the rainy season. Currently, geological disaster events still occur even after careful evaluation of its stability and management. The applicant believes that the main reason is that there is no objective consideration of the spatial variability of the parameters of such slopes in the stability evaluation, resulting in an unreasonable evaluation model system, and the evaluation results are not beneficial to management and are not applicable to eliminating the threat of disasters. Therefore, it is proposed to evaluate the stability of gravel soil slopes under rainfall conditions considering the spatial variability of parameters. Firstly, the intrinsic main controlling factors of the stability evolution of the slope system are determined based on case studies, and the effect of its variability characteristics on the spatial variability of parameters is investigated. Based on this, the spatial variability characteristics and combination patterns of gravel soil slopes are determined, and the geological structure model is obtained. Subsequently, via the comprehensive use of physical model tests and numerical simulations, the influence of spatial variability of parameters on the stability of slopes under rainfall conditions is investigated, and parameters, variability characteristics, and survey areas that should be focused on in practice are proposed. Then, the influence of spatial variability of parameters on the stability of the slope is verified by typical slopes, and the theoretical basis and method for evaluating the stability of such slopes in consideration of the spatial variability of parameters are proposed. The research results have important theoretical and application values for improving the evaluation and prediction of slope stability.

碎石土斜坡在自然界广泛分布，在雨季经常失稳，目前在其稳定性预测评价与管理中常造成地质灾害事件。申请者认为主要原因在于稳定性评价中没有客观考虑该类斜坡的参数空间变异性，造成从评价模型系统就开始不合理的状况，其评价结果必然是不易于管理与消除灾害威胁。因此，本申请拟从参数空间变异性角度开展碎石土斜坡在降雨条件下的稳定性预测评价。通过实例调查确定斜坡系统稳定性演化的内在主控因素，研究其变异性特点对参数空间变异性的作用规律，确定碎石土斜坡的参数空间变异性特征及其组合模式，构建地质结构模型；综合运用物理模型试验和数值模拟研究参数空间变异性对斜坡在降雨条件下稳定性的影响规律，提出实践中应重点关注的参数、变异性特征以及调查区域。再以典型斜坡验证参数空间变异性对稳定性的影响规律，提出该类斜坡考虑参数空间变异性的稳定性评价理论方法。研究成果对提高斜坡稳定性评价与预测水平具有重要理论意义和应用价值。

特性参数空间变异性是碎石土斜坡随机结构的参数化表征，其合理确定对于降雨下碎石土斜坡稳定性准确评价与管理至关重要。本项目揭示了碎石土斜坡特性参数空间变异性特征及其对斜坡降雨入渗稳定性的作用机制，探索了基于参数空间变异性识别的碎石土斜坡降雨入渗稳定性评价新方法。.项目基于碎石土滑坡实例资料统计分析，明确了碎石土斜坡常见地质类型，确定了碎石土斜坡稳定性的内在主控因素为碎石土斜坡物质组成，获得了碎石土斜坡物质组成与特性参数的统计特征；建立了碎石土斜坡参数空间变异性的野外调查方法，对残积、崩积、坡积成因碎石土斜坡实例开展调查，定量化确定了碎石土斜坡特性参数空间变异性特征，并基于随机场理论提出了不同成因碎石土斜坡参数空间变异性的随机表征方法；设计开发了多成因碎石土斜坡降雨入渗变形破坏室内模型试验系统，通过降雨斜坡模型试验，揭示了物质组成及特性参数空间分布特征对碎石土斜坡地下水分布和变形破坏的作用规律，证明了特性参数空间变异性对斜坡稳定性平均水平有重要影响；基于自行开发的渗流-稳定性数值分析平台，阐明了特性参数空间变异性对降雨下碎石土斜坡稳定性平均水平和不确定性的影响规律，揭示了粘聚力、内摩擦角、变形模量和饱和渗透系数等主要特性参数的空间变异性对降雨下碎石土斜坡稳定性的作用机制和不同特性参数空间变异性对碎石土斜坡稳定性作用的相对大小，认为粘聚力的空间变异性对碎石土斜坡稳定性起到关键作用；提出了在实践中对此类斜坡应重点关注的特性参数及其空间变异性特征；综合建立了基于参数空间变异性的碎石土斜坡降雨入渗稳定性评价理论依据与方法。依托相关研究成果发表国内外权威期刊论文10篇，其中SCI检索5篇，EI检索1篇，北大中文核心检索4篇。.研究成果对于碎石土介质斜坡稳定性准确评价、斜坡潜在破坏面的早期识别和斜坡浅层破坏现象的解释有重要科学意义与应用价值。