盾构隧道端头垂直杯型冻结壁温度场数值分析

摘要

This paper give an outline of the reinforcement structure of shield tunnel end's vertical cup-shaped and frozen wall,frozen wall temperature field of the vertical cup type are simulated.the main result is:the vertical cup of frozen wall stratum reinforcement is suitable for the end of shield tunnel at water rich sand in soft soil area,which can effectively solve the problem of the conventional reinforcement method`s poor quality in this area;the numerical simulation results show that when the frozen 30d,frozen average thickness is more than 1.6m,the method is feasible;with the increasing of thermal conductivity,numerical model to transition time is shortened,the phase transition between is reduced accordingly;at the same time freezing,the greater the volume heat capacity of soil temperature is high,the cooling rate is slow;with the increase of the amount of original ground temperature,soil cold cooling to increase the cooling time,growth.The results can provide technical reference for similar engineering design in the future.%本文对盾构隧道端头垂直杯型冻结壁加固结构作了简单介绍,对该垂直杯型冻结壁的温度场进行了数值分析,主要得出:该垂直杯型冻结壁适合作为软土地区富含水砂层端头的地层加固方式,可有效解决该地区常规加固方式加固效果不佳的问题;数值模拟结果表明:当冻结30 d后,冻土帷幕平均厚度大于1.6 m,该工法可行;随着导热系数不断增大,数值模型到达相变的时间缩短,相变时间也相应缩短;在相同冻结时间内,容积热容越大土体温度越高,降温速度越慢;随着原始地温的升高,土体降温所需要的冷量增大,降温时间增长.所得结果可为今后类似工程设计提供技术参考依据.