Abstract:

Based on the accurate determination of structural sequence and framework, a set of thinking and approaches were explored which includes establishing structure model, determining boundary conditions, selecting mechanical parameters and hazard prediction criterion of rock masses, calculating the value of paleo-tectonic stress, and predicting hazard areas and safety island. The plane stress model and three dimensional model were established by using of finite element method. Paleo-tectonic stress acted on Chengzhuang mine were simulated from its loading way and loading value. By the joint of rock of earth surface and coal bed ,we can calculate its internal frictional angle and ability of resistance to distortion, and obtain the critical region, risk region and safety region of ground surface and coal seam 3#. Combined with the structural features of joints, faults, folds, and subsided columns of studying area, we can integrate forecast the hazard zonation of the mine. The prediction results reveal that there are two large stage paleo-tectonic movement at Chengzhuang Coal Mining Area of Jincheng in Shanxi province; first with the north-south direction and later with west -east direction, first loading 60 MPa toward west-east and later loading 110-180 MPa toward north-south, the possible hazard area separated into eastern zone and western zone. The conclusions have important significance for the prediction of coal rock mass stress concentrated zone and gas outburst area.

Key words: paleo-tectonic stress, tectonic modeling, hazard prediction, joint, rock mass mechanics