In the construction of subway tunnel, a connected aisle is often set in the middle section of the upper and lower parts of the tunnel. The connected aisle is set to increase the safety factor of the tunnel, known as the "escape route". Connected aisle construction is after the completion of the main tunnel and it would have impact on the main tunnel and the surrounding environment to a certain extent. Wastewater pumping house is often combined with connected aisle in construction, but the pumping house design is relatively conservative. Construction technology is constrained by space, so it is more likely to cause risks. Therefore, effective measures are crucial to ensure the safety of excavation. In this paper, the first support deformation risk of a connected aisle of Wuhan Metro tunnel is used as an example, which uses backfill backpressure, first support reinforcement methods and acceleration of the floor construction, providing reference of risk control techniques for similar projects.

Wuhan Metro Line 6 has to go under an existing station of the 2^nd line by the method of in advance tunneling construction. This article describes the construction process in advance of shield tunneling segment through a series of problems existing in the corresponding solutions, and analyzes the track surface during construction on the 2^nd line of settlement and the existing station building subsidence case of using shield empty push impact on the existing tunnel. Based on Wuhan metro Line 6 tunnel, this article carries out a systematic analysis on the early application of the existing tunnel excavation method and the shield push with no-load. On this basis, the article dissusses the shield tunneling segment results from the rail surface setflement of the existing track and station building cumulative settlement. The project also uses a special precipitation and strengthening programs to reduce the impact of the construction process on the existing line operator and provides a useful reference for similar engineering.