摘要
川东隔挡式背斜是一种特殊的岩溶地质构造,当隧道群穿越背斜区时常发生较大规模的工程灾害,并严重影响该地区的地下水环境。目前,在该特殊地质背景下用解析法难以有效预测由隧道开挖所引起的地下水渗流场变化。鉴于此,文章根据研究区水文地质条件,建立了概念模型,采用可视化标准软件Visual Modflow对该区地下水渗流场进行了预测计算。结果表明:在施工阶段,随着隧道群的开挖,渗流场明显改变,水位大幅下降,最大降深48 m,最大影响半径达2.3 km;封堵运营2年后,地下水渗流场基本恢复到开挖前状态,水位逐渐上升,约恢复到原水位下方1 m的位置。由此可见,隧道群开挖对该地区地下水环境的影响程度逐渐降低。通过对比现场实测数据表明,该模拟结果与实际情况吻合度极高,数值法可以较好地模拟预测隧道群开挖过程中隔挡式背斜区的渗流场变化。
The ejective anticline is a special geological karst structure found in eastern Sichuan, which may result in engineering hazards and could seriously affect the groundwater environment during tunnel group construction. Since it is difficult to effectively predict the induced variation of a groundwater seepage field by analytical methods, this paper establishes a conceptual model based on the hydrological conditions in the studied ejective anticline zone and predicts variation of the groundwater seepage field using Visual Modflow software. The results show that：1） with the excavation of tunnels, the seepage field changes are obvious and the water level declines sharply, with a maximum drawdown of 48 m and a maximum influential radius of 2.3 km; and 2） after a two-year operation with water being blocked, the water seepage field was almost returned to the normal state before excavation with the water level raised to 1 m below the original level, indicating that the influence of tunnel group construction on the ground water environment decreases gradually. The simulated results are consistent with the measured ones, proving the feasibility of this numerical method.
出处
《现代隧道技术》
EI
CSCD
北大核心
2015年第3期69-74,共6页
Modern Tunnelling Technology
关键词
隔挡式背斜
隧道群
地下水
渗流场
数值模拟
Ejective anticline
Tunnel group
Groundwater
Seepage field
Numerical simulation
