海中洲隧道扩建中原隧道塌方的处理技术

目前国内尚无相应的基于改建或扩建既有老隧道的设计规范和规程作为设计方案之依据,在改扩建过程中如何制定合理、可靠的设计方案和施工方案,以海中洲城市隧道扩建过程为例,通过对原塌方区情况调查分析、研究,提出地表注浆锚杆加固、塌腔处理、塌腔回填等综合整治措施。总结出以下结论:1)对于老隧道改扩建工程,首先应熟悉老隧道情况,其次通过多种手段做详细的地质勘察,为系统性设计方案提供充分的依据;2)对于波及地表的土质浅埋隧道塌方处理,应综合考虑各种因素及相互关系,采用全面系统的整治方案;3)"稳固既有坍塌面,快速处理封闭成环"是防止原塌方规模进一步扩大的关键,对塌腔壁采用喷、网、锚、撑综合加固是行之有效的方法。

Case Study on Treatment of Previous Collapse in Rehabilitation of Haizhongzhou Tunnel

In the rehabilitation of Haizhongzhou tunnel,the previous collapse should be treated.Comprehensive treatment measures,including consolidation by grouted anchor bolts installed from the ground surface,collapse cave treatment and collapse cave backfilling,are proposed on basis of investigation,analysis and study on the collapse site.Conclusions drawn are as follows：1） For tunnel rehabilitation works,the conditions of the existing tunnel should be investigated and detailed geological survey should be made so as to provide guidance for the systematic design of the rehabilitation;2） For collapse of shallow-covered soil tunnels with the ground surface being influenced,complete and systematic treatment should be made,with all factors and their relationship being considered;3） Reinforcing the existing collapse face,rapid treatment and rapid forming reinforcement ring are essential to avoid the further enlarging of the collapse scale;consolidating the collapse cave walls by means of shotcreting,wiremeshing,rock bolting and supporting is an effective method for collapse treatment.