城际铁路隧道大型溶洞特征及处理技术

安顺至六盘水城际铁路茨冲一号隧道DK95+730~DK96+017段施工开挖揭示出大型溶洞群,采用溶洞形态测量、隧底岩溶物探探测、桩基地质钻探及补充调绘等综合勘察手段,查明隧道洞身及隧底大型溶洞的形态特征,以及该区域水文地质情况。提出相应的处理措施:隧道洞身采用混凝土护拱、护墙及C20混凝土加固;拱部采用“锚网喷+型钢钢架”防护;隧底采用桩筏、“横向托梁+筏板”跨越和采用C25混凝土换填或回填,并加强隧道周边引排水措施,以确保岩溶水畅通。

Characteristics and Treatment Technology of Large Karst Cave of Intercity Railway

The construction of the DK95+730~DK96+017 section of the Cichong No.1 tunnel of the Anshun-Liupanshui Intercity Railway revealed a large group of caves.Comprehensive survey methods such as cave morphology measurement,tunnel bottom karst geophysical exploration,pile foundation geological drilling and supplementary mapping were used to find out the morphological characteristics of the tunnel body and the large karst cave at the bottom of the tunnel,as well as the hydrogeological conditions of the area.The corresponding treatment measures are proposed:for the tunnel body,adopt concrete arch protection,retaining wall and C20 concrete backfill for compaction;for arches,adopt anchor net spray+steel frame protection;for the tunnel bottom,adopt pile raft,transverse joist+raft slab span and C25 Concrete replacement or backfill,and strengthen the drainage measures around the tunnel to ensure the smooth flow of karst water.