堵排水方式对秦岭隧洞衬砌外水压力的影响研究  

Effect of water blocking and drainage way on external water pressure on Qinling Tunnel lining

作　　者：赵力 苏岩 王博 魏军政[2] 陶磊 ZHAO Li;SU Yan;WANG Bo;WEI Junzheng;TAO Lei(Hanjiang-to-Weihe River Valley Water Diversion Project Construction Co.,Ltd.,Xi′an 710024,China;China Railway First Survey and Design Institute Group Co.,Ltd.,Xi′an 710043,Shaanxi,China)

机构地区：[1]陕西省引汉济渭工程建设有限公司,陕西西安710024 [2]中铁第一勘察设计院集团有限公司,陕西西安710043

出　　处：《人民长江》2022年第7期148-153,共6页Yangtze River

基　　金：国家重点研发计划项目(2016YFC0401805);陕西省水利科技项目(2017slkj-26)。

摘　　要：为研究隧洞外水压力对衬砌结构的影响,针对引汉济渭秦岭隧洞的高地下水头特点,采用数值计算分别对无灌浆层和有灌浆层两类情况下衬砌完全不透水、渗透性较低、设置排水孔3种工况进行了研究,分析了不同工况下衬砌外水压力的变化,并以典型洞段的堵排水方案为例,验证了排水孔设计的合理性。结果表明:随着衬砌结构透水性的增强,作用于二次衬砌的外水压力逐渐降低;当衬砌具有一定渗透性而未设置排水孔时,灌浆层渗透系数越小,作用于衬砌上的外水压力越小,且随着灌浆层厚度增加,衬砌外水压力不断减小,渗流量不断降低,当灌浆层厚度达到一定程度后,衬砌外水压力值虽继续减小但降幅明显趋缓;采用围岩灌浆并设置排水孔,可使作用于二次衬砌上的外水压力大幅度减小,且有效降低渗流量。综上,采用围岩灌浆的同时设置排水孔可取得良好效果,使作用在二衬结构外表面的地下水压力水头基本接近于零,达到了设计要求。Aiming at high groundwater head exerted on Qinling tunnel in Hanjiang-to-Weihe River Valley Water Diversion Project, three types of linings, totally impermeable lining, low permeable lining, ling with drainage holes, were studied by numerical calculation considering without and with grouting layer.The variation of external water pressure on lining is analyzed under different working conditions, and the validity of drainage hole design is proved through typical tunnel section.The results show that the external water pressure on secondary lining decreases gradually with enhancement of lining′s permeability.When the lining is permeable partly and without drainage holes, the smaller the permeability coefficient of grouting layer is, the smaller the external water pressure on lining is, and the external water pressure and seepage flow on lining decreases with the increasing thickness of the grouting layer.However, when the thickness of the grouting layer reaches a certain level, the external water pressure on lining still decreases but with a mild reducing amplitude.The application of surrounding rock grouting and drainage holes can greatly reduce the external water pressure on secondary lining and reduce the seepage flow effectively.It is concluded that the surrounding rock grouting plus drainage holes has good effect, which could reduce groundwater pressure head on the second lining to nearly 0.

关 键 词：衬砌结构 围岩灌浆 排水孔 外水压力 渗透系数 秦岭隧洞 引汉济渭工程 

分 类 号：TV52[水利工程—水利水电工程]