城市地铁双护盾TBM穿越碎裂石断层加固范围及施工关键技术研究

Reinforcement Range and Key Construction Technology of Double Shield TBM Going Through Fractured Rock Fault in Urban Subway

为解决城市地铁双护盾TBM穿越断层破碎带时掌子面坍塌、卡机等施工难题,利用数值模拟软件模拟碎裂石断层加固与否及管片和围岩位移变化规律,确定隧道纵径向断层加固范围,研究了双护盾TBM穿越碎裂石断层注浆加固技术。研究结果表明:双护盾TBM施工中碎裂石断层影响范围主要为隧道纵向为1.15D范围,径向为2.3D范围,因此建议双护盾TBM穿越碎裂石断层时应在该影响范围内进行注浆加固;断层注浆加固时,利用超前钻机进行钻孔,调整优化注浆压力进行水泥-水玻璃双浆液注浆,同时提出TBM掘进参数建议值,形成了双护盾TBM穿越碎裂石断层施工技术;该施工技术效果显著,注浆加固后碎裂石混合物加固体强度提高了2.62倍,抵抗变形的能力得到了加强,确保了双护盾TBM顺利通过碎裂石断层,提前实现了孖雅区间隧道贯通。

In order to solve the construction problems of double shield TBM in urban subway such as heading face collapse and machine stuck when it goes through fault fractured zone,the numerical simulation software is used to first investigate the rule of segment and surrounding rock displacement change,then determine the reinforcement range of tunnel longitudinal and radial faults,and finally choose the grouting reinforcement technology of double shield TBM going through fault fractured rock. The results show that in the construction of double shield TBM,the impact range of cataclastic rock fault is mainly 1. 15D in longitudinal direction and 2. 3D in radial direction. Therefore it is suggested that grouting reinforcement should be carried out in the impact range when double shield TBM crosses cataclastic rock fault. In the reinforcement of fault grouting,advance drilling rig is used to drill holes,adjust and optimize grouting pressure for cement - sodium silicate double grouting,at the same time,the recommended value of TBM tunneling parameters is proposed,and the construction technology of double shield TBM crossing fractured rock fault is chosen. The effect of this construction technology is remarkable. After grouting reinforcement,the strength of macadam mixture reinforcement is increased by 2. 62 times,and the ability to resist deformation is strengthened,which ensures the smooth passage of TBM with double shield through the macadam fault and realizes the penetration of Fuya tunnel in advance.