Abstract: A mining area is located under a lake district.It mainly contains gold and copper mine with a higher grade.The ore body in the mining area belongs to the medium and thick ore body under soft surrounding rock with poor stability of roof.Combined with ore-body′s occurrence conditions and the existing mining conditions,the numerical simulation software FLAC^3D was adopted to investigate the stope parameters for three mining methods of medium-length hole sub-level caving with subsequent filling,shallow hole shrinkage stopping with back-filling,and the upward horizontal slicing and filling method.Based on comparison among 6 kinds of simulated mining processes on surrounding rock stress and displacement,the width and the length of stope were initially determined as 14 m and 40 m respectively; Based on the initial stope parameters,maximum and minimum principal stresses,and displacement of roof and pillar,the corresponding stope width parameters for three different mining methods were all determined to be 14 m,and the length was 40 m,40 m and 42 m respectively.Stress of roof and pillar,and rock movement should be monitored at any time to strengthen roof management and make filling in time.Finally,the main task at the next stage was put forward to determine the reasonable filling body strength and the filling material.

Key words: FLAC^3D, Soft surrounding rock, Thick ore-body, Mining method