Abstract:

In order to guarantee the successful receiving of shield in Dayang Station on Jinan Rail Trainsit Line R1 and the safety of the upper pipelines, an underwater receiving scheme for EPB shield under complex geological conditions is put forward; and the underwater shield receiving technologies, including vertical freezing consolidation, portal cutting, retaining wall and temporary support under plate, shield tunneling mode and parameter control, synchronous grouting and supplementary grouting and outer convex portal design, are described in detail. Some conclusions are drawn as follows: (1) The underwater shield receiving technology is recommended in extremely thick waterrich gravel stratum, in which the conventional reinforcement cannot work. (2) The portal cutting process should be optimized to reduce the construction risk. (3) By using different tunneling mode of shield, the successful underwater shield receiving can be successfully carried out. (4) The outer convex portal can avoid the risk of sealed one. (5) The deformation of the upper pipeline, 1.41 mm, shows that the abovementioned underwater shield receiving technology is feasible and rational.

Key words: metro tunnel, waterrich gravel stratum, EPB shield, underwater receiving, portal cutting, end soil freezing reinforcement, shield tunneling parameters, synchronous grouting