多年冻土公路路基水分迁移规律与成灾机制研究  

Study on Moisture Migration Rule and Disaster Mechanism of Permafrost Highway Subgrade

作　　者：彭惠[1] 魏尧 袁堃[1] 崔福庆[1,2] PENG Hui;WEI Yao;YUAN Kun;CUI Fu-qing(CCCC First Highway Consultants Co.,Ltd.,State Key Laboratory of Road Engineering Safety and Health in Cold and High-altitude Regions,Xi’an Shaanxi 710065,China;School of Geological Engineering and Geomatics,Chang’an University,Xi’an Shaanxi 710054,China)

机构地区：[1]中交第一公路勘察设计研究院有限公司高寒高海拔地区道路工程安全与健康国家重点实验室,陕西西安710065 [2]长安大学地质工程与测绘学院,陕西西安710054

出　　处：《公路交通科技》2023年第3期42-50,共9页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(42271490,41971095,42071083);中国交建科技研发项目(2020-ZJKJ-PTJS04,2020-ZJKJ-QNCX09,2021-ZJKJ-PTJS02)。

摘　　要：多年冻土水热状况是影响路基稳定性的关键因素。为探明路侧积水对多年冻土路基长期稳定性的影响,首先基于青藏公路长期病害调查与水热监测数据,采用数理统计方法分析了路基积水发育状况与路基病害之间的相关性。其次构建了多年冻土路基路侧积水水热模型,分析了多年冻土公路路基水分迁移规律,得到了积水入渗情况下的路基长期变形机理。最后结合现有工程建设,提出了多年冻土地区路侧积水处治原则与防治建议。结果表明:青藏公路病害大致可分为沉陷、裂缝和翻浆3类,分别占路基病害总数的71.2%, 17.1%和11.7%;在路侧有积水的情况下,病害率平均高出50%左右;路侧积水对路基病害的影响主要体现为:水分渗透路径越短,路基高度越高,多年冻土地基含水率越高,路基病害发生几率越大;积水在路侧10 m范围内时病害率在20%以上,在10~30 m范围时病害率在5%~10%之间,在大于30 m范围时保持在5%左右;多年冻土路基含水率小于25%时,病害率不到10%,含水率处于25%~35%之间时,病害率在15%以上,含水率大于35%时,超过35%路段出现病害;在路侧积水入渗情况下,路基长期变形呈现出震荡增长的趋势,20 a内路基含水率为25%, 35%和45%时,长期沉降量分别达21.8, 25.6, 27.6 cm,路基工后沉降较大。基于上述研究结果提出的采用冲击碾压、抛石挤淤、以桥代路等工程处治措施,可为多年冻土地区公路新建和改扩建工程提供参考和借鉴。The hydrothermal condition of permafrost is a key factor affecting the subgrade stability.In order to find out the influence of roadside ponding on the long-term stability of permafrost subgrade,first,the correlation between the subgrade ponding development and subgrade distress is analyzed by mathematical statistics according to the long-term disease investigation and hydrothermal monitoring data of Qinghai-Tibet Highway(QTH).Second,a roadside ponding hydro-thermal model for the permafrost subgrade is built,the moisture migration rule of highway subgrade in permafrost is analyzed,and the long-term deformation mechanism of subgrade under the condition of moisture infiltration is obtained.Finally,combining with the existing project construction,the treatment principles and prevention suggestions against roadside ponding in permafrost areas are proposed.The result shows that(1)The QTH distresses can be roughly divided into 3 categories:subsidence,cracks and frost boiling,accounting for 71.2%,17.1%and 11.7%of the total subgrade distresses respectively.(2)In the case of roadside ponding,the distress rate is about 50%higher on average.(3)The influence of roadside ponding on subgrade diseases is mainly reflected in the following aspects:the shorter the moisture infiltration path,the higher the subgrade height,the higher the moisture content of permafrost subgrade,and the greater the probability of subgrade diseases.(4)The disease rate is more than 20%when the ponding is within 10 m of the roadside,within 5%-10%when the ponding is within 10-30 m,and about 5%when the ponding is more than 30 m.(5)When the moisture content of the permafrost subgrade is less than 25%,the disease rate is less than 10%;when the moisture content is between 25%and 35%,the disease rate is more than 15%;when the moisture content is more than 35%,the disease occurs in the section of more than 35%.(6)Under the condition of roadside ponding infiltration,the long-term subgrade deformation shows the concussive grow trend.When the moisture content of s

关 键 词：道路工程 成灾机制 数值仿真 路侧积水 工程处治对策 

分 类 号：U418.5[交通运输工程—道路与铁道工程]