Undercrossing tunnels are frequently constructed by the shield-driven method in metro projects.Shield tunneling affects the existing tunnel inevitably.

摘要在铁工程中，常采用盾构法修建正交下穿，的掘进不可避免对既有产生影。

The underground diaphragm wall in Yellow River Undercrossing Project of the Middle Route in the South-to-North Water Diversion is the deepest and thickest one in China.

北调中线穿黄工程下连续墙是国内最深最厚的下连续墙,质条件差,施工难度大,施工中存在较大的风险。