武汉长江隧道工程盾构始发井施工关键技术

武汉长江隧道工程盾构始发井工程位于长江南岸，施工场地距长江约500m，为长江一级阶地，地质条件差，承压水位高，且承压水与长江水有联系。同时基坑开挖深度大，周边环境复杂，施工难度极大。结合该工程介绍了高承压水软土地区深基坑防水、减压降水、基底加固等关键施工技术，根据规范和经验公式并对施工引起周边环境的沉降进行了评价。

Key Construction Technology of Shield TBM Launching Shaft of Wuhang Yangtze River Crossing Tunnel

The shield TBM launching shaft of Wuhan Yangtze River Tunnel Project is located on the south bank of Yangtze River, about 500m away from the Yangtze River, where the geology is of first bench terrace with poor geological condition and high level of artesian water connecting with the water in Yangtze River. Furthermore, the excavation of the foundation pit is deep and the surrounding environment is complicated. This paper introduces some technologies of deep foundation pit in soft soil with high artesian water pressure such as water proofing key construction , de-watering by reducing pressure and foundation bottom consolidation, and evaluates the settlement in surrounding area caused by construction according to relevant specifications and empirical formula.