盾构始发端垂直冻结温度场数值分析与现场实测  

Numerical Analysis and Field Measurement of Vertical Freezing Temperature Field at the Beginning of Shield Tunneling

作　　者：李晓娜 杨双锁[1] 鲍飞翔 赵智辉 LI Xiao-na;YANG Shuang-suo;BAO Fei-xiang;ZHAO Zhi-hui(College of Mining Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学矿业工程学院

出　　处：《科学技术与工程》2020年第1期297-302,共6页Science Technology and Engineering

基　　金：国家自然科学基金(U1710111);山西省重点研发计划重点项目(201703D111027)

摘　　要：太原地铁双塔西街站-大南门站区间盾构始发端采用垂直冻结法加固技术。由于盾构始发的特殊性,冻结帷幕的有效厚度能不能保证,是关系到土体加固是否安全的前提。通过建立三维数值模型对该工程冻结帷幕温度场随时间的发展规律展开研究,动态模拟冻结帷幕的演化过程,并且现场实时监测记录了冻结帷幕的温度变化和盐水温度随时间的变化情况,分析了在同一深度处各测温孔测点温度随时间的变化规律,计算了冻结帷幕厚度与冻结帷幕平均温度,验证了盾构是否具备始发的条件。结果表明:实测温度值和数值计算温度值总体趋势基本一致;采用垂直冻结方式、三排冻结管冻结施工的方案是合理的;用数值模型来模拟冻结帷幕温度场的变化过程是可行的。The vertical freezing method was used to reinforce the shield tunneling for the subway construction between Shuangta Xijie Station and Dananmen Station,Taiyuan City,Shanxi,central China.Because of the particularity of the shield initiation,whether the effective thickness of freezing curtain is enough and ensured is the precondition for the safety of portal reinforcement.To understand this problem,a 3-D numerical model was established for freezing engineering curtain research on temporal variation of the temperature field.In the model,the frozen soil evolution dynamically was simulated,real-time in-situ monitored,temperature of freezing curtain and temporal variation of the brine temperature recorded,temperature variation with depth and place analyzed,thickness and average temperature of the frozen wall calculated,and whether the shielding was ready with the initial conditions determined.The results show an overall consistent trend of temperature between the measured and the calculated.It is believed therefore,the scheme of vertical freezing method and three-row frozen pipe freezing construction is reasonable and the numerical modeling of the variation in temperature field of frozen soil curtain is practical.

关 键 词：地铁 人工冻结技术 数值计算 温度场 

分 类 号：TU445[建筑科学—岩土工程]