考虑THM耦合效应的富水砂层冻结效果评价  

Evaluation of Freezing Effect of Water-Rich Sand Layer Considering THM Coupling Effect

作　　者：沙立中 叶万军[2] 赵兵 汤明建 浦同茂 周子豪 符晓 SHA Lizhong;YE Wanjun;ZHAO Bing;TANG Mingjian;PU Tongmao;ZHOU Zihao;FU Xiao(China Railway 19th Bureau Group Rail Transit Engineering Co.,LTD.Kunming Project Science and Technology Research and Development Department,Beijing,China;School of Architecture and Civil Engineering,Xi′an University of Science and Technology,Xi’an Shaanxi,China)

机构地区：[1]中铁十九局集团轨道交通工程有限公司,昆明项目科技研发部,北京 [2]西安科技大学建筑与土木工程学院,陕西西安

出　　处：《太原理工大学学报》2025年第2期327-337,共11页Journal of Taiyuan University of Technology

基　　金：中铁十九局集团有限公司科技研究开发计划项目(21-Z03)。

摘　　要：【目的】地铁隧道穿越富水砂层时常用的人工冻结法在冻土过程中受热、流、力场协同作用,研究多场耦合冻结效果对应用人工冻结法确保土体止水与加固的有效性具有重要意义。【方法】以昆明地铁富水砂层联络通道人工冻结法加固工程背景,建立了三维水平杯型冻结热-流-力耦合场(THM)模型,探明了降温计划、地下水渗流速度、地层饱和度对冻结效果的影响规律,并与实测结果对比分析。【结果】研究结果表明:地下水渗流速度越大,下游冻结区域冻结效果越明显,不同渗流速度下外圈冻结壁交圈时间均发生延期;渗流速度越大,上、下游冻结壁厚度差相差越大;不同降温计划条件下,采用-25℃降温计划的冻结效果最佳;由冻胀引起的竖向位移及水平位移随着饱和度的增大而增大,竖向位移增长率大于水平位移,竖向位移最大可达8.43 mm,水平位移不超过1.80 mm。在实际工程中,冻胀应力对临近建(构)筑物造成影响,可与管片配合通过二次注浆和融沉注浆以规避失稳、渗漏和盾构轴线偏移的危险。【Purposes】The artificial freezing method is often used in subway tunnel crossing the water-rich sand layer,and is subjected to the synergistic action of heat,flow,and force fields during soil freezing process.It is of great significance to study the multi-field coupling freezing effect for the application of artificial freezing method to ensure the effectiveness of soil water sealing and reinforcement.【Methods】Therefore,on the basis of the engineering background of artificial freezing method in Kunming Metro,a three-dimensional horizontal cup-type freezing thermal-fluid-force coupling field(THM)model was established,and the effects of cooling plan,groundwater seepage velocity,and formation saturation on freezing effect were investigated,and compared with measured results.【Findings】The results show that the higher the seepage velocity of groundwater, the more obvious the freezing effect is in the downstream frozen zone. The larger the seepage velocity, the larger the thickness difference between the upper and lower frozen walls. For different cooling schedule condi tions, the freezing effect of -25℃ cooling schedule is the best. The vertical displacement and horizon tal displacement caused by frost heave increase with the increase of saturation. The growth rate of ver tical displacement is greater than that of horizontal displacement, the maximum vertical displacement is 8.43 mm, and the horizontal displacement is less than 1.80 mm. In practical engineering, the frost heave stress affects the adjacent structures, so the risk of instability, leakage, and shield axis devia tion can be avoided by secondary grouting and melt sink grouting combined with pipe segments.

关 键 词：热-流-力(THM)耦合 富水砂层 冻结效果 地铁联络通道 人工冻结法 

分 类 号：TU443[建筑科学—岩土工程]