圆梁山隧道毛坝向斜深埋大型充填溶洞及其形成机制分析  

Research on Characteristics and Formation Mechanism of Great Deep Buried Infilled Caves at Maoba Syncline in the Yuanliangshan Railway Tunnel

作　　者：蒋良文[1] 易勇进[1] 贾中明[1] 

机构地区：[1]中铁二院工程集团有限责任公司,成都610031

出　　处：《铁道工程学报》2007年第4期53-60,共8页Journal of Railway Engineering Society

基　　金：铁道部科技发展计划项目(2001G009A-1)

摘　　要：研究目的:圆梁山隧道施工开挖揭示,毛坝碳酸盐岩向斜核部和东翼在隧道洞身附近发育3个罕见的大型深埋充填溶洞,其中2#溶洞多次发生涌砂突水灾害,3#溶洞还发生过粘性土爆喷型突出灾害;通过对3个溶洞发育充填的基本特征及灾害特征的综合分析研究,阐明3个溶洞的形成机制,为整治设计提供地质依据。研究方法:采用地表与隧道洞内超前物探、洞内超前水平与斜向钻探、充填物测试和理论分析等方法。研究结果:通过综合勘探和理论分析,查明了3个溶洞各自发育充填的基本特征及灾害特征,初步阐明了溶洞的形成机制,目前3个溶洞已完成整治。研究结论:初步综合分析认为,毛坝向斜、特别是核部与东翼的层间滑脱和纵向张裂隙被NW^NWW向横张断裂所交切,为岩溶水的深循环提供了较通畅的原始空间与通道,岩溶水在此通道中形成倒虹吸循环,长期溶蚀及溶蚀裂隙流转化为管道流,强烈冲刷与顶板坍塌导致核部与东翼的层间滑脱和纵张裂隙部位发展为大型溶洞,后因深部径流条件改变而被逐渐充填,发育形成现今这种罕见的深埋大型充填溶洞。Research purposes： During construction of Yuanliangshan tunnel, it has been found that 3 infrequent great deep buried caves exists near Yuanliang tunnel at core and eastern wing of Maoba carbonate rock syncline. In 2^# cave of them occurred gushing water and sand many times. In 3^# cave occurred even bursting eruption of clayey soil. After integrated analysis and research is performed of the filling characteristics of the said 3 caves and disaster pattern and description has been made for their formation mechanism and the geological basis will be given to the disposal design of the potential geological disaster. Research methods：The geophysical prospecting on ground surface and in tunnel, horizontal drilling and incline drilling in tunnel, test of fillings in cave, theoretical analysis are applied. Research results：Through integrated prospecting and theoretical analysis, the basic features and disaster features of 3 caves developing and filling are found out. The formation mechanism of the caves has been defined preliminarily. The potential geological disasters of the 3 infilled caves have been disposed. Research conclusions：Bedding detachment and longitudinal tension fractures located at core and eastern wing of the Maoba syncline cutting by transverse tension fractures（ NW- NWW） , form the initial space and route way, which are the passage the deep cycle of karst aquifer. A type of deep flow cycle named inverse siphon cycle forms. The flow water dissolves the carbonate rocks along the route way. Conduits are formed by perennial corrosion of the water. The great cave forms due to corrosion and collapse of ceiling the cave. The cave is filled by clayey soil, which deposits due to the changes of the flow.

关 键 词：倒虹吸循环 深部径流 深埋充填溶洞 毛坝向斜 圆梁山隧道 

分 类 号：U451[建筑科学—桥梁与隧道工程]