Study on construction influence of shield tunnels traversing adjacently under underground large-scale structure

A 3D FEM model of the shield driving was established.Under the construction conditions of different shield driving forces and without in-phase grouting,mutual influences of construction of shield tunnels traversing adjacently under existing underground large-scale structures were studied with the numerical simulation and 3D model tests.It was shown that the shield driving exerted a limited effect on the underground structures,the “excursion” of existing tunnel did not occur.The effects of uplift resistant piles on the underground structure were obvious.Tension stress and compression stress of the bottom board in the underground structure occurred alternately,thus the maximum absolute value of stress decreased.Linings of newly-built tunnel and exiting tunnel were safe during the construction and operation,and the special design for linings was not needed.To ensure the safety of construction,it was necessary to use the measurements to adjust the pose of the shield to slow down the driving speed and to control the driving force within 10000 kN,when the shield machine was walking at a distance less than 10 m from the edge of upper underground structures.