A New Residual Subsidence Prediction Method of Short Working Face Goaf for Safety Construction of Urban Viaduct

Abstract

The planned viaduct in Jining, Shandong is a priority project in the city, but the 63 working face of a mine in Jining is only 3m away from the planned viaduct, which poses the serios threat to safety construction of the viaduct. Therefore, it is necessary to evaluate the stability of the planned viaduct goaf area under the influence of 63 working face. However, the 63 working face is a short face, and the corresponding prediction of surface residual subsidence is lacking. For this purpose, the theoretical analysis and numerical simulation were employed in this paper to reveal the foundation deformation mechanism and characteristics of fractured rock and soil mass of short goaf. It was concluded that the main source of residual subsidence was the stripping and yield softening of the coal wall on both sides of short goaf. Then, the residual subsidence prediction method of short goaf was proposed for viaduct mined-out area. The new method was applied to the planned viaduct of Jining, and the effectiveness of the method was proved by InSAR and leveling monitoring results. The research results provided the technical support for viaduct construction under the influence of underground mining.