Aiming at the Shanghai metro tunneling line No.4

that is

a tunnel within ultra-near distance crossed through the adjacent operating metro line No.11

the three-dimensional finite element method was applied to analyze the deformation distribution of the existing tunnel. The deformation analysis is based on three elements: different clearance distance

earth pressure of the chamber

injecting quantity of grout. Based on the results of the numerical modeling and theory of orthogonal analysis

the concept of influence coefficient for the overlapping tunnel is inferred. Through the results of orthogonal analysis

it was shown that: in the procession of overlapping

the distance affects the displacement field of the existing tunnel evidently; the influence on the earth pressure is secondary

injecting quantity effects slightly. These results could provide valuable preference to the technology of micro-perturbation control in the construction of overlapping tunnels.