Testing of the stress in strata immediately surrounding the fault and analysis of the impacts on the stability of the roadway surroundings

摘要

A case under study is that the roadways for coal conveying and air returning in a coal mine in Huainan lie near Fault 24 (F24 for short, and henceforth).For this reason, the testing of the stress in the nearby surroundings and the analysis of the impacts by the stress on the strata will be of great significance.The testing and analysis were conducted in the following manner.With drilling points determined and marked in advance, core drilling was conducted in 4 places in the upper and lower strata of F24 by turning to level positioning and core obtaining devices.The cores so obtained were marked in a 3-dimintional coordinate.Then in the laboratory, the angle for drilling was determined again.And by using the core-obtaining device in combination with the sampling drill, samples were obtained in 6 different directions.Then by using RMT-150B in combination with DS2-8B, the ground stresses for the 6 samples were tested.Later, by turning to VB 6.0, the magnitudes and directions for the 3 major stresses of the core were determined and the magnitudes for the stresses of the upper and lower strata of the roadway were made known.As the next step, by turning to ANSYS, the analysis was conducted of the impacts exercised by the upper and lower stresses on the corresponding strata.The results thus obtained contribute significantly to the technique selection for supporting roadways in complicated strata.