公路高边坡灾变机理及滑动力响应规律分析

降雨是导致和诱发滑坡的主要因素，据调查中国大约68%的滑坡灾害是由于降雨作用所致。为揭示降雨诱因与边坡岩土体劣化变形之间的关联性，以大广高速新丰段边坡为例，对降雨诱发边坡失稳破坏模式展开研究。通过建立降雨与开挖条件下的大广高速新丰段边坡的三维数值计算模型，分析滑坡应力场和位移云场演变规律，确定了滑动面埋深(H=14 m)和滑动面地表出露位置，并发现滑动面出露处呈“后缘张拉V形裂缝、舌部挤压隆起变形”为主的破坏模式，坡面以蠕滑变形为主的破坏模式；开展新丰段边坡“耦合锚索框架梁+抗滑桩”加固设计及可行性数值模拟分析；最后，在新丰段边坡上建立了公路边坡滑动力综合在线安全监测预警系统，揭示了滑动力随降雨量的动态响应规律。结果表明：在抗滑桩加固位置，坡体Z方向变形量减小，最大变形量仅为9 mm,满足边坡控制要求。可见，为类似公路高边坡的安全监测和变形机理研究奠定了理论和实践基础。

Analysis of disaster mechanism and sliding force response law of highway high slope

Rainfall is the main factor that causes and induces landslides. According to the survey, about 68% of landslide disasters in my country are caused by rainfall. Therefore, revealing the correlation between the rainfall inducement and the deterioration and deformation of the slope rock and soil mass is the basic way to fundamentally prevent and control rainfall-induced landslide disasters. Taking the slope of Xinfeng section of Daguang Expressway as an example, this paper studies the influencing factors and failure modes of slope instability induced by rainfall. Firstly, a three-dimensional numerical calculation model of the slope of the Xinfeng section of Daguang Expressway under the conditions of rainfall and excavation is established, the evolution law of the stress field and displacement cloud field of the landslide is analyzed, and the buried depth of the sliding surface (H = 14m) and the position of the outcrop on the sliding surface, and it is found that the outcrop of the sliding surface shows the main failure mode of "trailing edge tension V-shaped crack, tongue extrusion uplift deformation", and the slope surface is dominated by creep deformation. Finally, the reinforcement design and feasibility numerical simulation analysis of “coupled anchor-cable frame beam + anti-sliding piles” for the slope in Xinfeng section were carried out, and it was proved that at the reinforcement position of anti-sliding piles, the deformation in the Z direction of the slope decreased, and the maximum deformation Finally, a comprehensive online safety monitoring and early warning system for highway slope sliding force was established on the slope of Xinfeng section, which revealed the dynamic response law of sliding force with rainfall. With the increase of rainfall, the deep sliding force suddenly rised, and the slope was deformed. The main failure modes included frame beam cracking and "tongue"-shaped failure of the rock and soil mass on the slope surface. The deformation mechanism research has laid a theoretical and practical foundation.