渗流地层地铁联络通道冻结壁形成过程及其影响因素分析  

Formation process of freezing wall of subway cross passage inseepage stratum and analysis of its influencing factors

作　　者：刘欣 冯利华[4] 任全军[4] 沈宇鹏[1] 韩昀希 刘越 韩风雷[2,3] LIU Xin;FENG Lihua;REN Quanjun;SHEN Yupeng;HAN Yunxi;LIU Yue;HAN Fenglei(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;Institute of Future Civil Engineering Sciences and Technology,Chongqing Jiaotong University,Chongqing 400074,China;School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;2nd Engineering Co.Ltd.,China Railway First Bureau Group,Tangshan 063000,China)

机构地区：[1]北京交通大学土木工程学院,北京100044 [2]重庆交通大学未来土木科技研究院,重庆400074 [3]重庆交通大学土木工程学院,重庆400074 [4]中铁一局集团第二工程有限公司,河北唐山063000

出　　处：《中南大学学报（自然科学版）》2024年第4期1463-1476,共14页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(42172291);北京市自然科学基金资助项目(8212014)。

摘　　要：冻结法凭借封水性好、适应性强和环境影响小等优势成为地铁联络通道施工的主要工法之一,而地下水渗流易引起冻结壁交圈时间延后、厚度和平均温度不及预期,对冻结工程的推进具有不利影响。本文采用频域反射法获取饱和砂砾石未冻水体积分数和温度的函数关系式,基于多孔介质传热和渗流理论,建立考虑相变的饱和地层渗流冻结流热耦合数学模型,利用联络通道冻结模型试验结果验证流热耦合模型的有效性。在此基础上,研究渗流速度、冷媒温度、冻结管直径和渗流温度对联络通道冻结壁形成过程和交圈时间的影响规律。最后,采用正交试验方法对冻结壁形成过程影响因素的显著性进行分析,提出考虑多因素影响的冻结壁交圈时间和标厚时间预测方法。研究结果表明:无渗流时,联络通道冻结温度场呈W型对称分布;当渗流速度为51.2 m/d时,地层温度场不再呈对称分布,上游区域温度高于下游区域温度。渗流速度是影响联络通道冻结壁形成的首要因素,冻结管直径和冷媒温度次之,渗流温度对交圈时间的影响较小。上游侧墙是渗流地层冻结壁扩展的薄弱环节,应加强该区域温度场的监测,跟踪冻结壁的形成过程。Artificial ground freezing is one of the common methods for the construction of subway cross passage due to good water sealing,wide adaptability and less environmental impact.However,delayed time of closure time,thickness and average temperature of the frozen wall are easily caused by groundwater seepage,which has a negative impact on the progress of freezing engineering.Based on the theory of heat transfer and seepage flow in porous media,a hydro-thermal coupling model in saturated strata considering phase change was proposed.The functional relationship between the unfrozen water volume fraction of saturated sandy gravel and temperature was established using frequency domain reflection method.The proposed model was verified using the results of model test.On this basis,the effect of seepage velocity,refrigerant temperature,freezing tube diameter and seepage temperature on the formation process and closure time of the freezing wall was investigated.Finally,the significance analysis of the influencing factors on the formation process of freezing wall was conducted using orthogonal experimental methods,and a prediction method for closure time and standard time of freezing wall considering multiple factors was proposed.The results show that the freezing temperature field of the cross passage is symmetrically distributed in a W-shape without seepage flow.At 51.2 m/d,ground temperature field is asymmetrically distributed in which the temperature in the upstream is higher than that in the downstream.Seepage velocity is the primary factor affecting the formation of the freezing wall of the cross passage,followed by the freezing tube diameter and refrigerant temperature,and the seepage temperature has less influence on the closure time.The upstream side wall is the weak area for the expansion of the freezing wall under seepage condition in which the temperature should be monitored intensively to track the formation process.

关 键 词：联络通道 人工地层冻结 冻结壁 渗流 温度场 

分 类 号：TU43[建筑科学—岩土工程]