Abstract: During constant unloading inside a deep excavation, the vertical and horizontal displacements at the adjacent combined utility gallery will occur. When the deformation of the combined utility gallery is excessive, it might cause the leakage at the deformation joints of the gallery and cracks within the utility gallery structure, thus, affect the normal operation of the utility gallery. This paper presents threedimensional finite element analysis results by using commercial software MIDAS GTS NX. The influence of large deep excavation on the deformation of the adjacent combined utility gallery in soft soil area is evaluated. The results of 3D FEM analysis and field monitoring were compared. The results show that the supporting option of bored pile plus a concrete strut (hanging from the bottom) has a good effect on the deformation control of the deep excavation in soft soils.

Key words: mucky soil, deep excavation, combined utility gallery, shield tunnel, numerical simulation