高压富水地层水工隧洞衬砌外水压力确定与应对措施  

Methods to cope with external water pressure of hydraulic tunnel linings in high-pressure groundwater-rich strata

作　　者：刘立鹏[1] 汪小刚[1] 段庆伟[1] 傅睿智 姜龙[1] LIU Li-peng;WANG Xiao-gang;DUAN Qing-wei;FU Rui-zhi;JIANG Long(China State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100048,China)

机构地区：[1]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100048

出　　处：《岩土工程学报》2022年第8期1549-1557,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家重点研发计划课题(2016YFC0401804);中国水利水电科学研究院基本科研业务费专项项目(GE0145B012021);国家自然科学基金面上项目(51879284,52179121);流域水循环模拟与调控国家重点实验室自主研究课题(SKL2022ZD05);云南省重大科技专项计划项目(202102AF080001)。

摘　　要：针对高压富水地层外水压力带来的衬砌设计难题及安全稳定问题,整理分析了多个实际工程外水压力监测成果,结合室内模型试验,研究论述了水工隧洞衬砌外水压力与所赋存环境岩体地下水活动状态以及衬砌排水能力间的关系;为解决采用传统复合衬砌可能存在的底板外水压力较大的偏压问题,提出了一种新型复合衬砌结构型式,并从控制渗流量及外水压力角度,对富水地层水工隧洞渗控设计标准进行了探讨。结果表明:水工隧洞衬砌外水压力主要受衬砌排水系统排水能力控制,同时与所赋存环境岩体地下水活动状态相关,依照规范中推荐方法确定外水压力具有明显不足;所提出的新型复合衬砌结构型式,可有效解决由于排水孔降压范围有限、底板外水压力较大导致的偏压问题;建议采用复合衬砌结构的水工无压隧洞允许排放量选择为3.0 m3/(m·d),衬砌外水压力不超过0.5 MPa,设计中可依据该标准确定排堵水结构相应参数。研究结果可为富水地层水工隧洞外水压力应对措施的选择提供技术支撑。To solve the problems of lining design and safety caused by external water pressure in water-rich strata, the monitoring results of external water pressure in several practical projects are analyzed. Based on the model test results, the relationship among the external water pressure acting on the hydraulic tunnel linings, the groundwater activity in rock mass and the drainage capacity of linings is discussed. A new type of lining structure is proposed to solve the eccentric pressure problem of the traditional composite linings which may have a higher external water pressure applying on the lining bottom. The seepage control design standard of hydraulic tunnel in water-rich strata is discussed from the perspective of seepage flow and external water pressure control. The seepage control design criterion of hydraulic tunnel in water-rich strata is then discussed from the perspective of seepage control and external water pressure control. The results show that the external water pressure of hydraulic tunnel linings is mainly controlled by the drainage capacity of lining drainage system, and is related to the groundwater activity in the surrounding rock mass. To determine the external water pressure according to the method recommended in the specification in China is not accurate. The new proposed lining structure can effectively solve the eccentric pressure problem of linings because of the limited pressure reduction range of drainage holes and the larger water pressure on the lining bottom. It is suggested that the allowable discharge of hydraulic non-pressure tunnels with the traditional composite lining structure should be 3.0 m3/(md), and the external water pressure of lining should be below 0.5 MPa. The corresponding parameters of lining drainage and shutoff structures can be determined according to these two values. The research conclusion can provide technical support for the selection of coping method for the external water pressure problem of hydraulic tunnels in water-rich strata.

关 键 词：水工隧洞 富水地层 应对措施 渗控标准 

分 类 号：TU43[建筑科学—岩土工程]