Secondly, a new tunnel was drilled nearby the existing tunnel with various distance-to-diameter ratios (d/D), and the jacking force was applied on the tunnel face.

• 现行一般多采用潜盾工法来进行隧道开挖工作，在施工过程中，由于地盘应力变化导致周边地盘变位，亦造成地表结构物受损。