Correlation Between Railway Subgrade Settlement and Shield Tunneling Construction

Abstract

With the rapid development of cities, relevant rail transit construction also develops at a high speed. However, the construction space above the ground is limited, and rail transit covering large construction area is often constructed underground, so the shield tunnel is bound to be used for the underground rail transit construction. In this study, the influence of shield tunneling construction on railway subgrade was analyzed using numerical simulation method, and the influence of stratum reinforcement measures on subgrade in construction process was also analyzed. The results showed that shield tunneling construction could cause subgrade settlement and the influence became larger and larger with the proceeding of project. When the left line was completed, the maximum settlement point was located above the center line of the left tunnel, and the settlement was 7.506 mm. When the right line was completed, the maximum settlement point was located above the central line of the two tunnels, and the settlement was 9.970 mm. Grouting reinforcement measures for stratum around the tunnel could significantly reduce the settlement; the maximum settlement decreased by 62.84% when the left line was completed and 58.65% when the right line was completed. To sum up, shield tunneling construction of railway will cause subgrade settlement, and stratum grouting reinforcement measures can significantly reduce subgrade settlement.