Numerical simulation of freezing effect and tool change of shield machine with a frozen cutterhead  

盾构机冷冻刀盘换刀方法及冷冻效果仿真模拟研究

作　　者：DAI Wei XIA Yi-min XU Hai-liang YANG Mei 代为;夏毅敏;徐海良;杨妹(College of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China;China Railway 25th Bureau Group Co.,Ltd.,Guangzhou 510600,China)

机构地区：[1]College of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China [2]China Railway 25th Bureau Group Co.,Ltd.,Guangzhou 510600,China

出　　处：《Journal of Central South University》2020年第4期1262-1272,共11页中南大学学报（英文版）

基　　金：Project(2014FJ1002)supported by the Science and Technology Major Project of Hunan Province,China;Project(2012AA041803)supported by National High Technology Research and Development Program of China。

摘　　要：A shield machine with freezing function is proposed in order to realize tool change operation at atmospheric pressure. Furthermore, the transformation project of freezing cutterhead and tool change maintenance method are put forward. Taking the shield construction of Huanxi Power Tunnel as an example, a numerical analysis of the freezing cutter head of the project was carried out. The results show that when the brine temperature is-25 °C, after 30 d of freezing, the thickness of the frozen wall can reach 0.67 m and the average temperature drops to-9.9 °C. When the brine temperature is-30 °C, after 50 d of freezing, the thickness of the frozen wall can reach 1.01 m and the average temperature drops to-12.4 °C. If the thickness of the frozen wall is 0.5 m and the average temperature is-10 °C, as the design index of the frozen wall, the brine temperature should be lower than-28 °C to meet the excavation requirements in 30 d. Analyzing the frozen wall stress under 0.5 m thickness and-10 °C average temperature condition, the tensile safety factor and compressive safety factor are both greater than 2 at the most dangerous position, which can meet the tool change requirements for shield construction.为了实现常压换刀作业,提出了一种具有冻结功能的盾构机,并且提出了冷冻刀盘的改造方案和换刀维护方法。以环西电力隧道盾构施工为例,对该工程冷冻刀盘进行了数值分析。结果表明,当盐水温度为-25°C时,冻结30 d后,冻土的冻结壁厚可达0.67 m,冻土平均温度降至-9.9°C。当盐水温度为-30°C时,冻结50 d后,冻结壁厚可达1.01 m,平均温度降至-12.4°C以冻结壁厚度为0.5 m,平均温度为-10°C作为冻结壁设计指标时,盐水温度应低于-28°C,以满足30 d的开挖要求。通过对0.5 m厚、-10°C平均温度下的冻结壁进行应力分析得出:最危险位置的抗拉、抗压安全系数均大于2,满足盾构施工换刀要求。

关 键 词：shield machine CONSTRUCTION frozen cutterhead tool change maintenance finite element simulation 

分 类 号：TU621[建筑科学—建筑技术科学] TU994