高水压TBM隧道管片泄水方案研究  

Research on Water Drainage Schemes for Segments in High Water Pressure TBM Tunnels

作　　者：李永利 LI Yongli

机构地区：[1]中铁十五局集团第二工程有限公司,上海201714

出　　处：《重庆建筑》2024年第10期67-71,共5页Chongqing Architecture

摘　　要：针对某TBM隧道所遇到的大埋深高水头问题,提出了径向注浆堵水、仰拱对称泄水与深孔泄水3种方案,降低管片衬砌所承受的水压力,并借助理论计算与数值模拟手段对3种方案的泄水效果进行了评估,主要结论如下:(1)此种工况下,仅依靠管片与防水密封垫的防护能力不能满足隧道安全性要求;(2)采用径向注浆堵水方案可以有效降低水压。当注浆层厚度大于6 m时满足设计要求。此种方案对围岩的水压力分布没有影响,减小了隧道开挖对围岩应力场的影响,保证了围岩的稳定性;(3)采用仰拱对称泄水方案时,需要在注浆层和管片之间施作一层薄透水层,以便让水能充分汇集到泄水孔位置;(4)采用深孔泄水方案时,每环管片泄水孔数量为6个,并且泄水管超出管片外表面1.2 m时,能够满足管片的泄水要求。此种方案整环管片的降水效果更加均匀,结构安全系数更高。Addressing the issue of large burial depth and high water head encountered in a certain TBM tunnel,three schemes are proposed:radial grouting for water blocking,symmetrical water drainage through inverted arch,and deep-hole water drainage,to reduce the water pressure borne by the segment lining.Theoretical calculations and numerical simulations are employed to evaluate the water drainage effects of the three schemes.The main conclusions are as follows:(1)Under such working conditions,relying solely on the protective capabilities of the segments and waterproof sealing gaskets cannot meet the safety requirements of the tunnel;(2)The radial grouting scheme for water blocking can effectively reduce water pressure.The design requirements are met when the thickness of the grouting layer exceeds 6 m.This scheme has no impact on the water pressure distribution of the surrounding rock,reduces the impact of tunnel excavation on the stress field of the surrounding rock,and ensures the stability of the surrounding rock;(3)When adopting the symmetrical water drainage scheme through the inverted arch,a thin permeable layer needs to be constructed between the grouting layer and the segments to allow water to fully collect at the drainage holes;(4)When adopting the deep-hole water drainage scheme,six drainage holes per ring of segments are sufficient to meet the drainage requirements of the segments when the drainage pipes extend 1.2 m beyond the outer surface of the segments.This scheme provides more uniform precipitation effects across the entire ring of segments and a higher structural safety factor.

关 键 词：铁路隧道 TBM隧道 高水压 泄水管片 

分 类 号：U451[建筑科学—桥梁与隧道工程]