Abstract: There are strenuous ground pressure activities at the -280 m level in the central mining area of Gongchangling Mine，so that the high-strength support can not solve the problems that are caused by the ground pressure.The destructions of roof falling，rib spalling and floor heave still occur even after the roadways have been supported，which have seriously affected the normal production of the mine.It is indicated that the ground pressure activity is basically caused by the pressure of the above wedge-shape rock mass based on the investigation of the failure positions of the haulage roadway，the test results of the rock mechanics properties and the analysis of the effect of the hanging wall to the stability of the roadways.The mechanic model is established and the analysis results have been proven based on the calculation of the model.The yielding angle is determined to be from 74°to 78° by analyzing the relationship between the mining boundary in the hanging wall and the destruction boundary of the roadways.Based on the yielding angle，the rock mass can be divided into the elastic zone and the plastic zone.The hanging haulage roadway at the -340 m level is located in the elastic zone，so the yielding development is adopted in this area.The practice shows that the yielding development can effectively alleviate the problems that are caused by the ground pressure in the hanging haulage roadway and ensure the normal production of the mine.

Key words: Ground pressure behavior, Wedge pressure, Normal stress, Pressure relief angle, Elastic deformation area, Plastic deformation area, Yielding development