地下水渗涌是影响隧道施工及建成运营的一个重要因素，隧道涌水引起力学、物理和化学作用，并影响围岩水力学和变形特性。隧道涌水将导致强度降低、膨胀、变形，以至于围岩失稳破坏。以长大深埋特长隧道为例，在分析隧道涌水特性的基础上，结合室内试验与现场监测，系统分析隧道涌水对围岩特性的影响，包括强度、围岩变形、膨胀性等。结果表明，隧道涌水量越大、岩体越破碎，其对围岩特性的影响越显著。

 GIT (groundwater inflow into tunnels) is one of the important factors that have adverse effects on the construction and operation of tunnels, which can result in mechanical, physical and chemical effects and has impact on the hydromechanics and deformation characteristics of the surrounding rock masses. GIT can result in strength reduction, expansion and deformation of the surrounding rock mass, even instability and failure of the surrounding rock masses. Taking superlong tunnels with great covers as example, the authors make systematic analysis on the effects of GIT on the characteristics of the surrounding rock masses, including strength, deformation and expansion characteristics of the surrounding rock masses, on basis of analysis on the characteristics of water inflows and laboratory experiments and field measurements. The conclusion indicates that the larger of the water inflow rates and the worse of the rock masses, the greater the effects on the characteristics of the surrounding rock masses are.