岩溶区地铁盾构隧道施工关键技术研究

Research on Key Construction Technology of Metro Shield Tunnel in Karst Area

依托贵阳市轨道交通3号线师范学院站—东风镇站盾构区间工程,基于现场实际施工方案,总结了溶洞探测预报技术、岩溶处理技术、盾构掘进参数控制以及地表沉降监测信息化反馈技术等岩溶区盾构隧道施工关键技术。实践表明,重视岩溶区域的溶洞探测及预报是保障岩溶区盾构施工安全的重要前提,建议浅部采用地质雷达方法,中深部以孔中物探为主(跨孔CT与管波方法),复杂地质条件及复杂环境条件时采用微动新技术进行加密探测的浅—中—深精细化岩溶勘察综合物探模式;做好盾构施工的同步注浆与二次注浆工序对地表沉降控制十分有利。

Aiming at the shield tunnel project of Guiyang Rail Transit Line 3 from Shifanxueyuan station to Dongfengzhen Station,and based on the actual construction scheme on site,the key construction technologies of shield tunnel in karst areas are summarized,such as detection and forecast technology of karst caves,treatment technology of karst caves,shield tunnelling parameter control,and information feedback technology for surface subsidence monitoring.Practice has shown that attaching importance to cave detection and forecasting in karst areas is an important prerequisite for ensuring the safety of shield construction in karst areas.It is recommended to use the comprehensive geophysical exploration mode of shallow-middle-deep refined karst exploration,including geological radar method in the shallow part,and the geophysical prospecting in the hole(cross-hole elastic wave CT and tube wave method)in the middle and deep part,and the microtremor surrey technology is used for intensified detection in complex geological conditions and complex environmental conditions.The simultaneous grouting and secondary grouting procedures in shield construction are very beneficial to the control of surface settlement.