含交叉断层深埋隧洞围岩衬砌外水压力物理模型试验  

Physical model experiment of external water pressure in lining surrounding rock of a deep tunnel with cross faults

作　　者：王如宾[1] 王新越 张文全 徐卫亚[1] 陆进彬 向天兵 WANG Rubin;WANG Xinyue;ZHANG Wenquan;XU Weiya;LU Jinbin;XIANG Tianbing(Research Institute of Geotechnical Engineering,Hohai University,Nanjing 210098,China;Yunnan Dianzhong Water Diversion Engineering Company Limited,Kunming 650000,China;Kunming Engineering Corporation Limited,Power China,Kunming 65005l,China)

机构地区：[1]河海大学岩土工程科学研究所,南京210098 [2]云南省滇中引水工程有限公司,昆明650000 [3]中国电建集团昆明勘测设计研究院有限公司,昆明650051

出　　处：《清华大学学报（自然科学版）》2024年第7期1179-1192,共14页Journal of Tsinghua University(Science and Technology)

基　　金：云南省重大科技专项计划项目(202102AF080001)。

摘　　要：为揭示复杂地质条件下富水区深埋隧洞围岩灌浆圈衬砌复合系统的外水压力作用规律,该文自行研制适用于深埋隧洞的大型高外水压力物理模型试验测试系统,选取滇中引水工程昆明段松林隧洞TSLT-005与TSLT-006(TSLT-005、TSLT-006为断层编号)交叉断层典型洞段为研究对象,开展含交叉断层深埋隧洞衬砌外水压力物理模型试验,揭示不同隧洞埋深、不同地下水位及不同排水条件下,衬砌的外水压力变化规律,并给出各工况下的外水压力折减系数建议取值范围。结果表明:隧洞埋深和地下水位对衬砌结构的外水压力影响明显,随着隧洞埋深的增大,受高地应力影响,围岩与灌浆圈自身的孔隙度与渗透性下降,对地下水渗流势能起到较好的削弱作用,导致衬砌的外水压力整体呈降低趋势;随着地下水位升高,衬砌全环的外水压力呈增大趋势,且由于岩体中细颗粒会被高水压冲散,因此形成较为连通发育的渗流通道,渗压增速也会随地下水位的升高而增大;设置衬砌排水孔可有效降低隧洞拱肩及其以上部位的外水压力,当隧洞围岩存在交叉断层分布时,断层带影响的衬砌部位外水压力降低效果受到一定削弱,且对衬砌的外水压力分布影响较为明显,在高地下水位工况下,需重点关注“断层带”对围岩衬砌结构整体的影响范围;当衬砌结构不排水时,600 m埋深的外水压力折减系数约为200 m埋深的92%,设置排水孔后,600 m埋深的外水压力折减系数约为200 m埋深的85%;当隧洞围岩存在交叉断层时,在不排水情况下,衬砌最不利点的外水压力折减系数建议取值0.95以上,在排水条件下,衬砌处的外水压力折减系数建议放宽至0.82;最后,利用有限元数值模拟方法对衬砌的外水压力物理模型试验结果进行验证,在衬砌不排水工况下,误差约为9.3%,在衬砌排水工况下,误差约为7.8%,表明高外水压力作用物理模型装�[Objective]To elucidate the action mechanisms of external water pressure on the composite system of surrounding rock,grouting ring,and tunnel lining under complex geological conditions,a large-scale high external water pressure physical model experimental system suitable for deep-buried tunnels was developed.[Methods]The typical tunnel sections of the Songlin Tunnel TSLT-005 and TSLT-006 cross faults in the Kunming section of the Central Yunnan Water Diversion Project were selected as the research objects.The research encompassed physical model experiments on the external water pressure impacting the tunnel lining in deep-buried environments crossed by faults.The study aimed to determine the pressure variation laws across different tunnel depths,groundwater levels,and drainage conditions,proposing a range of recommended values for external water pressure reduction coefficients applicable under various operational scenarios.[Results]The findings indicated that tunnel depth and groundwater level substantially impact the external water pressure exerted on tunnel linings.An increase in tunnel depth enhanced the geostress effects,which,in turn,decreased both the porosity and permeability of the surrounding rock and grouting circle.This reduction effectively diminished the potential energy of groundwater seepage,thereby lowering the overall external water pressure on the lining.Conversely,rising groundwater levels increased the full-ring external water pressure on the lining,with high water pressure dispersing finer particles within the rock mass and fostering the development of more extensive seepage channels.This reduction also resulted in a higher rate of infiltration pressure increase correlated with rising groundwater levels.Furthermore,incorporating drainage holes into the lining substantially lowered the external water pressure affecting the upper shoulder areas of the tunnel.However,the presence of cross faults within the surrounding rock of the tunnel can mitigate the effectiveness of this pressure reduction,e

关 键 词：滇中引水隧洞 物理模型试验 高外水压力 断层破碎带 

分 类 号：TV672.1[水利工程—水利水电工程]