Investigation of Water Leakage of Metro Segments Caused by Metro Underpass Structures

Abstract

Water leaking into metro segments is related directly to the presence of underground water. However, to date, the underground confined water channels formed by metro underpass reinforcement structures have not been considered as causes of the problem. In the present study, based on field investigations and geological data, confined water is identified as the source of segment leakage on Line 5 of Hangzhou Metro in China. It is then hypothesized that the problem stems from an underground confined water channel formed under the reinforced structure of the subway. Numerical simulations predict a settlement difference of 8–10 mm between the reinforcement area and the weak strata, and field monitoring data show this difference to be 8.62 mm. This consistency between the numerical simulations and the field measurements verifies the hypothesis. Finally, given the causes of underground confined water channels, corresponding technical measures such as piecewise secondary grouting are proposed to cut them off and avoid metro-segment leakage. The present research results contribute to the causes of and the laws governing the metro-segment leakage that occurs at subway stations and other reinforced structures.

Analytical Study to Assessment the Stability of the Al-Askarian Underpass in Najaf

“…Failure occurs in the underpass for several reasons, the most prominent of which is lateral pressure, which often leads to overturning [1,9] in the ground corridor, in addition to weak soil resistance under the foundation of the tunnel, which leads to slipping [2] in the tunnel or shearing in the soil itself, so it is necessary to Knowing the chemical and physical properties of the soil [5,6,7,8] for its importance in calculating the bearing capacity [3,4], with the necessity of calculating the resistance of the tunnel to the ascending forces.…”