摘要
泥水盾构工法被广泛应用于高压富水复杂地质环境中修筑隧道,其中开挖面稳定控制是工程成败的关键,在盾构掘进时,由于刀盘不断旋转切削地层,开挖面上的泥膜处于“形成―破坏―再形成”的动态循环过程,泥膜透水性增强,这种动态泥膜作用下开挖面的稳定如何评价有待于进一步探索。对此,对泥水盾构掘进过程中的动态泥膜进行了分类,提出了考虑盾构运动和泥浆渗滤特征的动态泥膜理论。在此基础上,采用空间离散法将泥水压力引入旋转体模型,建立了考虑动态泥膜效应的开挖面稳定力学模型,提出了泥水盾构动态掘进过程中开挖面临界泥浆压力及泥浆支护效率评估方法,研究指出:当盾构在强渗透性地层中掘进时,在尽量提高泥浆成膜率的同时,应注重泥浆黏度调节,充分发挥渗透力支护作用,同时可适当提高盾构掘进速度并降低刀盘转速,有利于开挖面稳定控制。以泥浆成膜率、等效渗透系数为依据给出了泥浆支护效率设计图,研究工作对盾构掘进支护压力控制和泥浆配置有一定的借鉴意义。
Slurry shield tunnelling method is widely used in the complex geological environment with high water pressure for tunnel construction. The face stability control is the key for the engineering safety during shield tunnelling. Due to the continuous rotation of the cutter head, the filter cake is in the "formation-destruction-re-formation" dynamic cycle process, resulting in a relative permeable membrane. How to evaluate face stability under this dynamic filter cake need to be further explored. In this paper, the dynamic filter cakes are divided into three types. An analytical approach is developed by coupling the penetration-filtering and shield movement.Based on the pressure transfer mechanism of the bentonite suspension, a new penetration-type model for the evaluation of face stability is developed. It can be found that the slurry viscosity as well as the filter cake ratio should be paid more attention during tunnelling in the high permeable ground. A faster advance rate and a lower rotation speed of the shield machine could improve the face stability. Finally, a design chart of slurry support efficiency is provided, which could give some reference for the control of support pressure and slurry selection in engineering practice.
作者
金大龙
袁大军
JIN Da-long;YUAN Da-jun(Key Laboratory for Urban Underground Engineering of Ministry of Education,Beijing Jiaotong University,Beijing 100044,China;School ofCivil Engineering,Beijing JiaotongUniversity,Beijing100044,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2022年第11期2952-2962,共11页
Rock and Soil Mechanics
基金
中央高校基本科研业务费专项资金资助(No.2021RC231)
国家自然科学基金青年基金资助项目(No.52008021)
高速铁路基础研究联合基金资助项目(No.U1834208)。
关键词
泥水盾构
动态泥膜效应
开挖面稳定
支护效率
泥浆配比
slurry shield tunnelling
dynamic filter cake
face stability
support efficiency
slurry selection