Model test and analysis of the overhand cut and fill stoping

Based on the underground mining engineering with overhead cut and fill stoping in the slightly inclined medium thick phosphate layer of pit 6^# of Jinning phosphate mine of Yunnan Phosphate Chemical Group Co.，the test scheme，the material proportion，the test rig，the excavation simulation method，and the measurement technology of the model test for overhand cut and fill stoping are researched and explored.Moreover，the laws of rock stress and deformation，and the loose zone in the process of overhand cut and fill stoping are researched and analyzed，through plane strain similar simulation model test and numerical simulation.Research results show that：① rock failure mainly appears in the middle of roof in the model test，and the failure mode is block falling；② the variation of the vertical stress of the rock forms an arch shape，and the center of the arch is the mine goaf；③ maximum displacement occurs in the middle of the roof，and develops towards the goaf，thus the displacement variation of the surrounding rock near excavation side should be paid much attention.