大跨度双连拱隧道开挖渗流场特征研究

连拱隧道特殊的结构型式导致了连拱隧道在渗漏水防治方面存在较大的困难,对大跨度的连拱隧道而言,这种现象尤为突出。要研究地下水在连拱隧道中的渗漏,首先要研究连拱隧道施工过程(开挖步骤)对渗流场的影响。文中对南京九华山大跨度双连拱隧道所在工程区的工程地质及水文地质特征进行了分析,根据场地岩体的基本性质,采用二维渗流分析方法,对九华山隧道在不同开挖(加固)步骤中的渗流场特征进行了详细的研究,得出在不同开挖步骤中隧道围岩的渗透压力及渗透梯度,指出渗透压力及渗流速度较大的部位,为隧道及时加固以及防排水设计提供理论基础。

Research on Seepage Field Characteristics of Excavation for Large Span Doubled Arch Tunnel

The groundwater leakage preventing of doubled arch tunnel lies more greater difficulty on account of its especial structure.It is stand out especially as to large span doubled arch tunnel.To avoid the groundwater leakage in doubled arch tunnel,the seepage field characteristics are studied during doubled arch tunnel excavation firstly.The hydrogeology and engineering geology characteristics in Jiuhua Mountain of large span doubled arch tunnel are researched.According to rock mass characteristics in the field,2D seepage field analysis method is adopted.The seepage field characteristics of different excavation(consolidation) steps are researched for Jiuhua Mountain of large span doubled arch tunnel.The result shows that the seepage pressure and seepage gradient of different excavation steps are obtained.The positions of their maximum value in the tunnel are pointed out.It provides theoretical basics for consolidation in time and preventing and drainage design of the doubled arch tunnel.