寒区富水隧道冻结圈围岩冻胀力演化规律研究  

Evolution Law of Frost-Heaving Pressure of Frozen Circles in Surrounding Rock around Water-Rich Tunnels in Cold Regions

作　　者：郑新雨 徐飞 孙浩凯 高阳[2] 蔚立元[3] ZHENG Xin-yu;XU Fei;SUN Hao-kai;GAO Yang;WEI Li-yuan(Geotechnical and Structural Engineering Research Center,Shandong University,Jinan 250061,Shandong,China;Key Laboratory of Large Structure Health Monitoring and Control,Shijiazhuang Tiedao University,Shijiazhuang 050043,Hebei,China;State Key Laboratory for Geomechanics&Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,Sichuan,China)

机构地区：[1]山东大学岩土与结构工程研究中心,山东济南250061 [2]石家庄铁道大学河北省大型结构健康诊断与控制实验室,河北石家庄050043 [3]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [4]西南交通大学土木工程学院,四川成都610031

出　　处：《中国公路学报》2022年第9期340-351,共12页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51808359);河北省青年拔尖人才项目(BJ2020055);河北省自然科学基金项目(E2019210356);中国博士后科学基金项目(2019M663553);深部岩土力学与地下工程国家重点实验室开放基金项目(SKLGDUEK1916)。

摘　　要：寒区富水隧道冻结圈围岩冻胀演化机制是影响其运营安全的关键科学问题。为探究冻结圈围岩的冻胀力演化规律,开展含水围岩低温冻结作用下三维地质力学缩尺模型试验;采用环境冷气进入洞内降温的方式,模拟隧道洞口段围岩温度场分布特征;利用微型压力传感器对含水围岩在低温冻结过程中的冻胀力进行实时动态监测,以获取不同含水率和冻结圈厚度围岩下的冻胀力时空演化曲线。采用多元回归分析方法,建立围岩冻胀率、冻结圈厚度与含水率等参数的拟合计算式;据此建立平面应变状态下考虑围岩含水率和围岩比重指标的冻结圈围岩冻胀力理论解。采用热应力方法模拟冻胀力演化特征,对冻胀力的理论计算值和模型试验测试值进行对比分析,进一步验证试验方法和理论解的合理性。研究结果表明:围岩温度场呈三阶段变化特征以及类似带柄状“正勺”形状分布规律;含水围岩温度场的下降阶段呈非线性分布特征;围岩温度表现出滞后于环境温度变化的趋势。不同含水率和冻结圈厚度下的冻胀力演化规律曲线形态类似,表现为孕育-发展-稳定变化特征。冻胀力理论解与现场实测数值偏差19.7%,与数值解、试验值偏差均在0~20%之间,所提出的冻胀力理论计算方法可为围岩含水率为0~60%范围和冻结圈厚度为0~8.0 m范围冻胀力取值提供参考。研究结论可为寒区富水隧道冻结圈围岩的冻胀力设计及预测研究提供支持。The frost-heaving evolution mechanism of frozen circles in surrounding rock around water-rich tunnel is a key scientific problem that affects the operation safety in cold regions. To explore the evolution law of frost-heaving pressure in frozen circles in such surrounding rock, scaled three-dimensional geomechanical model tests were carried out. In these tests, freezing of a water-bearing surrounding rock at low temperature was considered. The temperature field distribution characteristics of surrounding rock at the tunnel portal section was simulated by introducing ambient air into the tunnel for cooling. Micro-pressure sensors were employed to dynamically monitor the frost-heaving pressure in real time. The spatial and temporal evolution curves of the frost-heaving pressure were obtained for various water content and thickness in surrounding rock. The fitting formulas for parameters such as the frost-heaving rate of surrounding rock, thickness of the frozen circles, and water content were established utilizing multiple regression analysis. Based on this, a theoretical solution for the frost-heaving pressure of the frozen circles in surrounding rock under plain strain state was derived considering the influence of water content and proportion index of surrounding rock. The thermal stress method was used to simulate the evolution characteristics of frost-heaving pressure. Combined with numerical simulations, the test method and theoretical solution were further verified by comparing the predicted frost-heaving pressure with the theoretical and test values. The results indicate that the temperature field of surrounding rock undergoes changes in three stages. This is similar to a regular spoon with a handle-like evolution process;the temperature field of the water-bearing surrounding rock exhibits a non-linear distribution in the descending stage;the temperature field of surrounding rock shows a lagging characteristic relative to the environmental temperature. The shape of the frost-heaving pressure evolution curve

关 键 词：隧道工程 冻胀力 模型试验 冻结圈 含水率 寒区 洞口段 

分 类 号：U451[建筑科学—桥梁与隧道工程]