In view of the high gas pressure and low permeability deep coal seam, it is difficult to control gas, which affects safety production mine. The technical scheme hydraulic fracturing improve seam put forward, drainage technology used emission seam. effect under different water pressure, gradient times, in situ stress analyzed by using 3DEC (3-Dimensional Distinct Element Code) discrete element s...

A major element in the site investigations the Swedish Nuclear Fuel and Waste Management Co (SKB) conducts in order to select the most suitable area to site the final repository has been the measurement of the in situ stresses. In situ stress measurement, carried out inside a few boreholes, often very scarcely placed in a large area, cannot in detail reflect the spatial distribution of the in s...

The rockfall process is characterized by bounces of a block on the ground. coefficient restitution (COR), which indicates degree energy dissipation, has significant effect trajectory. 3-dimensional Distinct Element Code (3DEC) an effective tool to study trajectory, and damping can reflect COR in numerical modeling. However, relationship between not understood. A field test numerically modelled ...

The overlying strata of the stope can be divided into low ( immediate roof ), medium and high according to degree influence mine pressure behavior working face. Among them, step distance rock judged appearance hydraulic support, middle not accurately intuitively determined only by theoretical calculation. Therefore, IMU is used monitor motion state fracture different layers, so as study relatio...

Underground structures at shallow depths are often constructed for metro lines, either in loose or dense layered soils. Tunnelling in urban areas is predominantly under surface structures and on tunnelling, innumerable changes in the form of distortion take place in strata surrounding the tunnel. Extent of displacement/damage to buildings or the tunnel-soil structure interaction depends on the ...

The application of fault-slip seismic sources is critical to the success ground motion dynamic response analysis. Previous research established a finite source analyze stability in underground engineering. In this paper, sophisticated numerical method based on distinct element (3DEC) proposed simulate an laboratory (URL) exploration tunnel. Two indices, i.e., peak velocity (PGV) and strain ener...