沪昆客专何家地隧道出口煤矿采空区沉降分析

Analysis of Settlement in Coal Mine Goaf for the Exit Section of Hejiadi Tunnel of Shanghai-Kunming High-speed Railway

研究目的:沪昆铁路客运专线何家地隧道出口D1K976+780~D1K977+208段在施工过程出现二衬变形开裂病害,地表产生长大贯通裂缝,严重影响隧道正常施工及开通运营。本文通过地质调查、煤矿资料收集、下井实测、物探、钻探、变形监测等综合勘察手段,对引起病害的煤矿采空区进行综合勘察,从而为何家地隧道病害整治提供可靠依据。研究结论:(1)通过综合勘察查明了引起隧道病害的煤矿采空区位于隧道左侧,最近距左中线约32 m,路基面以下183~225 m;(2)综合分析确定了煤矿采空区移动参数、变形参数及垂直分带;(3)基于变形监测成果,分析煤矿采空区从初始期、活跃期到衰退期的沉降特征,评价采空区沉降对铁路隧道的影响;(4)本研究成果可为类似煤矿采空区工程地质勘察及分析采空区沉降规律提供参考。

Research purposes:Deformation and cracking of secondary lining and long continuous cracks on ground occurred in the exit section D1 K976+780~D1 K977+208 of Hejiadi tunnel of Shanghai-Kunming high-speed railway during the construction process,which would seriously affect the normal construction and operation of the tunnel.This paper surveyed the cause of the geologicl disease in coal mine goaf compressively through integrated surveying means including geological survey,coal mine data collection,well logging,geophysical exploration,drilling,deformation monitoring,which can provide reliable basis for Hejiadi tunnel geologicl disease control.Research conclusions:(1)Through integrated investigation,this study found out that the coal mine goaf caused tunnel disease is located on the left side of the tunnel,with the closest spot being about 32 m from the left center line and 183~225 m below the tunnel bed.(2)The moving parameters,deformation parameters,and vertical zoning of the coal mine goaf were determined by comprehensive analysis.(3)Based on deformation monitoring results,the subsidence characteristics of coal mine goaf from initial period and active period to declining period were analyzed,followed by the assessment of the influence of goaf subsidence on railway tunnel.(4)The research result can provide reference for engineering geological investigation and analysis of subsidence law of similar coal mines goaf.