冻结锋面移动控制的冻土冻胀控制研究  

Research on frost heave mitigation based on the control of the movement of the freezing front

作　　者：季雨坤 王海航 周国庆[1] 赵晓东[1] 王钦科 李瑞林[1] JI Yukun;WANG Haihang;ZHOU Guoqing;ZHAO Xiaodong;WANG Qinke;LI Ruilin(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Civil Engineering and Architecture,Southwest University of Science and Technology,Mianyang,Sichuan 621010,China)

机构地区：[1]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 [2]西南科技大学土木工程与建筑学院,四川绵阳621010

出　　处：《中国矿业大学学报》2023年第5期943-951,共9页Journal of China University of Mining & Technology

基　　金：国家自然科学基金重点项目(42230704);江苏省基础研究计划项目(BK20221135);中国博士后基金项目(2022M723400);中央高校基本科研业务费专项项目(2022QN1038)。

摘　　要：人工冻结法用于地下工程建设时,过量的冻胀变形及冻胀力将抬升地层并导致构筑物的破坏及失效,提出冻胀控制方法及揭示冰透镜体生长抑制机理是推进人工冻结技术发展的重要途径.从冰透镜体生长速率和冰饱和度与渗透率的特定数学模型出发,得到了冻结缘厚度演化对冰透镜体生长速率的影响.研究指出,冰透镜体的生长对冻结缘结构具有强烈的依赖性,冻结锋面向冷端移动诱导的冻结缘结构退化将直接抑制冰透镜体的生长.通过研究冻结缘厚度对冰透镜体生长的影响机制,提出了基于冻结锋面移动控制的人工地层冻结技术思路,发展了相应的冻结控制系统及试验平台,该技术思路可有效激活冰透镜体的间歇性生长过程并实现对冻胀的控制.研究指出,减小设计冻结深度及提高冷端冻结温度均能有效抑制冻结土体中冰透镜体的生长及减缓冻胀.Excess frost heave and the ground deformation caused by frost heave pressure can lead to the failure of engineering structures when the artificial freezing method is used in underground engineering construction. Providing a frost heave control method and revealing the growth inhibition mechanism of the ice lens are an important way to develop the artificial ground freezing technology. Based on the exist mathematical model of ice lens growth rate related to ice saturation and permeability, the effect of frozen fringe thickness on the growth rate of ice lens is obtained. The results show that the growth of the ice lens is strongly dependent on the geometry structure of the frozen fringe, and the narrowing of the frozen fringe directly inhibits the growth of the ice lens. Considering the influence of the frozen fringe thickness on the growth mechanisms of ice lens, a freezing front control method is proposed as a new artificial freezing technical ideas, and the corresponding intelligent control system and experimental platform are innovated. The newly proposed freezing technical ideas can effectively activate the intermittent growth of the ice lens and realize the control of frost heave. The results show reduction of freezing depth or improvement of cold-end temperature can effectively retard the growth of ice lens and the development of frost heave.

关 键 词：冻结锋面 冻结缘 冰透镜体生长 冻胀减缓 冻土 

分 类 号：TU445[建筑科学—岩土工程]