Study on Excavation of Water Pump House in Deep Coal Mines in Xinhe

The excavation and support of deep chamber has always been a difficult problem to be solved urgently. Through a case study on the 980 m deep chamber group at Xinhe coal mine of China, the present research conducts theoretical analysis on the excavation-induced failure mechanism associated with the neighboring chambers. Moreover, a suite of construction workflows are optimized based on Flac3D numerical simulation. The optimal construction workflow BA(2)A(3)A(1)A(4)A(5) is determined by minimizing the damage volume V-P of the plastic region subsequently. The main chamber and niche of the pump house are supported by combined support, and the non-used support is adopted in the early and late stages of the construction of the pump house. The FLAC3D numerical simulator is adopted here to model the support scheme. Results show that the chamber deformation is effectively controlled at the top, bottom, and both sides. Results from field monitoring indicate that the overall supporting effect to the roadway is decent. In order to design the mining sequence of chamber group, FLAC3D numerical simulation can be used to optimize the scheme, and the combined support method adopted by chamber group is reasonable and feasible, which can effectively control surrounding rock, and has good application value.