水泥土地层冻融温度场全过程发展影响研究  

Study on the Influence of the Whole Process Development of Freeze-thaw Temperature Field in Cement Improved Soil Layer

作　　者：金修伟 鹿庆蕊[1] 李栋伟 陈士军[1] 张海军 洪进锋 JIN Xiuwei;LU Qingrui;LI Dongwei;CHEN Shijun;ZHANG Haijun;HONG Jinfeng(School of Civil&Architectural Engineering,East China University of Technology,Nanchang 330013,China)

机构地区：[1]东华理工大学土木与建筑工程学院,南昌330013

出　　处：《森林工程》2024年第3期184-196,共13页Forest Engineering

基　　金：国家重点实验室开放基金项目(NR1930);国家自然科学基金项目(52168044);江西省教育厅科技项目(GJJ2200702)。

摘　　要：为研究水泥改良土地层冻融温度场发展的影响因素,以广州地铁三号线某地铁隧道冻结工程为背景,通过水、热耦合的方式模拟隧道冻融温度场,研究其冻融温度场全过程发展影响规律,并与实测数据对比证明模型的精确性,分析导热系数、容积热容、原始地温和水泥掺量等因素对冻融温度场的影响。结果表明,土体在冻融温度场全过程发展过程中,先是大幅度降温,形成稳定冻结帷幕后,降温速率变缓,有效冻结壁厚度缓慢增加,进入自然解冻阶段后,温度快速上升直至达到相变阶段,在该阶段维持一段长时间后,土体迅速恢复正温;分析不同因素对冻结温度场的影响规律,其中土体容积热容,原始地温对冻结温度场冻结效果呈负相关,对于自然解冻温度场影响不大;土体导热系数的降低会抑制冻结温度场的发展,但是可以缩短自然解冻的周期;在水泥掺量为12%时,土体冻结效果最好,且融沉温度场发展速率最快,自然解冻周期最短。In order to study the influencing factors of the development of freeze-thaw temperature field in cement improved soil layer,this paper takes the freezing project of a subway tunnel in Guangzhou Metro Line 3 as the background,simulates the freeze-thaw temperature field of the tunnel through the coupling of water and heat,studies the influence law of the whole process development of the freeze-thaw temperature field,and proves the accuracy of the model by comparing with the measured data.The influence of thermal conductivity,volume heat capacity,original ground temperature,cement content and other factors on the freeze-thaw temperature field is analyzed.The results show that during the whole process of freeze-thaw temperature field development,the soil is greatly cooled first,and after forming a stable freezing curtain,the cooling rate slows down,and the thickness of the effective freezing wall increases slowly.After entering the natural thawing stage,the temperature rises rapidly until it reaches the phase transition stage.After a long period of time in this stage,the soil quickly returns to positive temperature.The influence of different factors on the freezing temperature field is analyzed.The volume heat capacity of the soil and the original ground temperature are negatively correlated with the freezing effect of the freezing temperature field,and have little effect on the natural thawing temperature field.The decrease of thermal conductivity of soil will inhibit the development of freezing temperature field,but it can shorten the period of natural thawing.When the cement content is 12%,the soil freezing effect is the best,and the development rate of the thaw settlement temperature field is the fastest,and the natural thawing period is the shortest.

关 键 词：地铁隧道 水泥改良土 冻融 温度场 数值模拟 

分 类 号：U455[建筑科学—桥梁与隧道工程]