软弱富水Ⅵ级围岩隧道下穿道路及数值分析

Numerical Analysis of Weak Enriched Water Surrounding Rock Grade Ⅵ Tunnel Under-passing Road

研究目的:针对江门隧道软弱富水Ⅵ级围岩段隧道施工难题,为保证隧道施工安全及下穿段道路的运营安全,选择合适的超前预加固方式和隧道开挖方法。研究结论:(1)采用施作水平旋喷桩超前加固、大管棚超前支护和CRD工法进行开挖,保证了隧道下穿段的施工安全。(2)借助有限元计算软件,对隧道开挖过程进行全过程数值模拟,对开挖过程中围岩应力和位移变化趋势进行分析,确定施工控制和地表变形监测重点。(3)在施工过程中钢架需及时封闭成环,防止底部出现较大的位移,产生底臌现象。

Research purposes： According to the difficulties in construction of weak enriched water surrounding rock grade VI Jiangmen Tunnel, the suitable advance reinforcement mode and tunnel excavation method were chosen, in order to ensure construction safety and road operation safety. Research conclusions： （ 1 ） The horizontal churning jet pile was used for the advance reinforcement, and the large pipe roof in advance and CRD method were used for excavation to safeguard the tunnel under - passing the road. （2） With the finite element calculation software, the numerical simulation was made for the whole process of the tunnel excavation, the analysis was made for change trends of the stress and displacement of the surrounding rocks excavation to decide the key points of the construction control and monitoring ground deformation. （3） The steel needed to be enclosed in time for a loop to prevent appearance of large displacement and floor swell.