冻融环境下“三段式”岩质边坡锁固段损伤破坏及灾变机制研究  

Study on damage and catastrophic mechanisms of the locked section of a“three-stage”rock slope in a freeze-thaw environment

作　　者：刘帅 杨更社[2] 潘振兴 LIU Shuai;YANG Gengshe;PAN Zhenxing(College of Civil Engineering and Architecture,Huanghuai University,Zhumadian,Henan 463000,China;College of Architecture and Civil Engineering,Xi'an University of Science and Technology,Xi'an,Shaanxi 710054,China)

机构地区：[1]黄淮学院建筑工程学院,河南驻马店463000 [2]西安科技大学建筑与土木工程学院,陕西西安710054

出　　处：《岩石力学与工程学报》2024年第11期2781-2795,共15页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(42177144)。

摘　　要：锁固段是“三段式”岩石滑坡的关键控制因素。为研究寒区边坡锁固段损伤破坏特性,对边坡缩尺模型开展双面冻融试验,分析水-冰相变过程中温度场、冻胀力及锁固段变形规律。依据岩石力学与断裂力学,构建考虑冰楔挤出效应的裂隙冻胀模型,探究裂隙边坡冻融风化机制。坡肩位置最先冻结,冻结峰由坡肩向岩体内部推进。“三段式”岩质边坡的断裂破坏由后缘张拉裂隙冻胀主导。后缘张拉裂隙顶端由-3.5℃降至-6℃(裂隙底部由0℃降至-2.6℃)时冻胀力最大,锁固段变形最大,锁固段开裂破坏也发生在此阶段。冻胀力与后缘张拉裂隙长度正相关,张拉断裂面基本没有剪切痕迹。通过模拟“三段式”岩质边坡后缘张拉裂隙的冻胀过程,分析边坡位移场、应力场分布特征,以及锁固段裂纹扩展路径,揭示锁固段角度与后缘张拉裂隙冻胀开裂和灾变机制的相关性。研究结果可为寒区边坡工程建设提供技术参考。The locked section is the key controlling factor of“three-stage”rockslides.In order to study the damage characteristics of the locked section of slopes in cold regions,a double-sided freeze-thaw test was carried out on the slope model,and the change of temperature field and the influence of frost heave force on the deformation during the water-ice phase transition were analyzed.Based on rock mechanics,a frost heave model considering the effect of ice wedge extrusion is established,and the mechanism of frost thaw weathering of crack slopes is investigated.The slope shoulder is frozen first,and the frozen peak advances from the shoulder into the rock mass.The fracture failure of the“three-stage”rock slope is dominated by frost heave of the tension fissure at the back edge.The frost heave force is the largest and the deformation of the locked section is the largest when the top of the rear edge tension crack drops from-3.5℃to-6℃(the bottom of the crack drops from 0℃to-2.6℃)and the cracking failure of the locked section also occurs at this stage.The frost heave force is positively correlated with the length of tensile fracture at the back edge,and there is no shear trace on the tensile fracture surface.By simulating the frost heave process of the tension crack at the back edge of the“three-stage”rock slope,the distribution characteristics of the displacement field and stress field of the slope and the crack propagation path of the locked section are analyzed,and the correlation between the Angle of the locked section and the frost heave cracking and the disaster mechanism of the tension crack at the back edge is revealed.The research results can provide technical reference for slope construction in cold regions.

关 键 词：边坡工程 冻融环境 “三段式”岩质边坡 锁固段 灾变机制 

分 类 号：P642[天文地球—工程地质学]