沉井井筒内水下开挖岩石技术难度大，既要保护井筒不受损伤，又要达到岩石破碎效果。
It is difficult to dig rock in sinking well due to the requirements of protecting well bore and achieving effective crashing of rock.
水下的隧道工程建设对周边地基的水力环境有很大的影响，而且容易诱导隧道的开挖工作面发生水力渗透。
Subsea tunnel will influence the hydraulic regime of the surrounding ground and tends to induce seepage towards the excavation boundary.
在开挖水下隧道时，要采用盾构向前推进。
In underwater tunneling, a shield is used to advance the work.
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