Abstract: A discrete element method for modelling fracture evolution of roadway surrounding rock is provided, which includes: taking rock cores from a coal seam in the field and recording RQD values, observing roadway deformation, and making a statistical analysis on distribution characteristics of fractures in the coal seam; testing mechanical parameters of coal-rock samples indoors, and calculating strength of a rock mass according to the RQD values; creating a numerical model by using a UDEC-Trigon module to adjust the parameters to match the strength of the rock mass, and correcting model parameters; and creating a numerical model of an engineering scale to adjust the parameters to match field deformation characteristics, and finally simulating fracture evolution of the roadway surrounding rock. The present invention provides accurate and basic mechanical parameters for discrete-element numerical simulation of roadway deformation, guaranteeing realistic and reliable simulation results.

Abstract: A discrete element method for modelling fracture evolution of roadway surrounding rock is provided, which includes: taking rock cores from a coal seam in the field and recording RQD values, observing roadway deformation, and making a statistical analysis on distribution characteristics of fractures in the coal seam; testing mechanical parameters of coal-rock samples indoors, and calculating strength of a rock mass according to the RQD values; creating a numerical model by using a UDEC-Trigon module to adjust the parameters to match the strength of the rock mass, and correcting model parameters; and creating a numerical model of an engineering scale to adjust the parameters to match field deformation characteristics, and finally simulating fracture evolution of the roadway surrounding rock. The present invention provides accurate and basic mechanical parameters for discrete-element numerical simulation of roadway deformation, guaranteeing realistic and reliable simulation results.

Abstract: A prefabricated stair modular assembly mold comprises a base, a step standard module, an upside module of a lower platform, an underside rotating module of a lower platform, an upside module of an upper platform, an underside rotating module of an upper platform, an underside common module, and an underside adjustment modules. Prefabricated stair molds of different dimensions are formed by means of locating holes provided in the assembling modules, and are then fixed by means of sliding holes at two ends. Further disclosed is a mounting method for said assembly mold. Said assembly mold has high positioning accuracy, and small accumulated error, improving the mounting efficiency of the prefabricated staircase mold.

Abstract: A prefabricated stair modular assembly mold comprises a base, a step standard module, an upside module of a lower platform, an underside rotating module of a lower platform, an upside module of an upper platform, an underside rotating module of an upper platform, an underside common module, and an underside adjustment modules. Prefabricated stair molds of different dimensions are formed by means of locating holes provided in the assembling modules, and are then fixed by means of sliding holes at two ends. Further disclosed is a mounting method for said assembly mold. Said assembly mold has high positioning accuracy, and small accumulated error, improving the mounting efficiency of the prefabricated staircase mold.