为充分了解隧道建设对地下水环境的改变, 在准确获取四川省松潘县某隧道围岩地质结构及相关渗透参数基 础上, 采用Visual Modflow 可视化三维软件, 模拟3 种方案( 天然条件、隧道开挖、隧道运营) 下5 种不同工况隧道建 设对地下水环境的影响。结果表明, 在天然状态下, 隧址区地下水位埋藏浅、变化较小, 地下水环境稳定; 隧道局部 开挖条件下, 地下水环境发生明显变化, 在隧道开挖段疏干范围明显增大, 地下分水岭向未开挖段偏移, 而未开挖段 地下水环境与天然条件相比变化不明显; 隧道贯通后, 地下水垂直向下流向隧道, 地下水疏干范围逐步扩大; 在加防 渗条件下, 地下水不再垂直向下流向隧道, 且地下水环境基本可以恢复到天然状态。综上, 在基岩裂隙山区建设隧 道时, 应同步进行防渗施工, 以减小工程建设对地下水环境的干扰, 同时也可以防止隧道涌突水事故的发生。

In or der t o understand the impacts of mountain tunnel constructio n on g ro undw ater envir onment, Visual Modflow , a three2dimensional visualization so ftw are, w as used to simulate the impacts of tunnel co nstr uction under fiv e wo rking co nditions on gr oundwat er env ir onment w ith three schemes ( natura l conditions, t unnel excav ation, and tunnel o per ation) based on the ac2 curate estimat ion o f the geolog ical structure o f surr ounding r ock and the r elevant par ameter s. The results show ed that ( 1) under the natural conditio ns, g ro undwater depth is shallow w ith little v ariation in the tunnel area, and g ro undwater environment is sta2 ble; ( 2) under the par tial ex cavation conditio ns, g ro undwater enviro nment changes obviously. Drainag e ar ea incr eases sig nifi2 cantly in t he tunnel ex cavatio n ar ea and g ro undwater div ide mo ves to the t unnel area w ithout excavation, but g r oundwater env i2 r onment in t he tunnel area wit ho ut ex cav ation is similar to that under natural conditio ns; ( 3) under t he complete ex cavatio n con2 ditions, g roundw ater mov es dow nw ard to the tunnel, and tunnel drainag e ar ea co ntinues to ex pand; and ( 4) under the anti2seepage conditions, gr oundwater no long er moves downward to the tunnel and gr oundwater env ironment can recover to the natur al conditions. Therefor e, anti2seepag e construction needs to be perfo rmed dur ing the mountain tunnel construction in or der to reduce the impacts of en2 g ineering construction on g roundwater environment and to prevent the w ater inrush accident in the tunnel.

国家自然科学基金资助项目( 40972175) ; 中央高校基本科研业务费专项基金( SWJT U11ZT14) ; 成都理工大学青年基金资助项 目( 2011QJ 23)