... ABSTRACT: The occurrence of floor heave, as mining depths increase over time, is a growing problem in the United States and abroad. A central Appalachian longwall mine operating in the Pocahontas No. 3 seam in Southwestern Virginia recently encountered excessive floor heave in the main...

... in southwestern Virginia mining in the Pocahontas Number 3 seam completed the longwall recovery in Panel 25. After the recovery was complete and mining resumed in Panel 26, slight floor heave of one or two inches was observed in the mains entries 7 and 8 just north of the Panel 25 recovery area. After...

... severe floor heave numerical simulation major principal stress calculation time reservoir geomechanics steel joist shale mineral china coal research institute Reservoir Characterization floor heave cohesion roadway tensile strength ARMA 17-0634 Numerical simulation of roadway squeezing...

... with pillar design. metals & mining floor material Upstream Oil & Gas floor failure strength moisture content basin loading traction Reservoir Characterization western shelf Illinois Basin moisture weak immediate floor material floor heave in-situ plate test database plate test...

... Abstract: Consistency between actual in-mine and modeled ground response to mining is essential if a model is to be used as a mine design tool. A new procedure is presented in this paper that infers Mohr-Coulomb floor properties that will synchronize floor heave behavior between mine...

... of the grouting pressure leading to floor heave is obtained. By numerical simulation method, the value of the grouting pressure carried by the surrounding rock is calculated. Through theoretical analysis and numerical simulation methods, the limit grouting pressure is determined in Longgu coal mine...

..., the relative vertical displacement of floor strata of the roadway, the narrow pillar and the high abutment zone are calculated. The mechanical principle of floor heave of the roadway is revealed. INTRODUCTION The coal face with fully mechanized top-coal caving is a kind of face in which the coal face...

... ABSTRACT: All mechanical factors of the floor heave in roadways, such as rock dilatancy, creep and buckling failure, are analysed here. The mechanism and rational parameters of two new kinds of stress relief methods are discussed by means of FEM. The stress relief method for roof was applied...

... appears to be the adequate solution for the type of tunnelling problem examined here. With this solution, a drastic reduction in swelling pressure on the lining is achieved by allowing a controlled amount of floor heave. 1 INTRODUCTION Rocks containing clay minerals and anhydrite increase in volume when...

...-and-pillar mining system may lead to problems of a) pillar settlement and instability, b) floor heave and squeeze, c) roof falls due to differential settlement of pillars, and d) surface subsidence movement. Unfortunately, even small subsidence movements may have adverse effects on surface land use...

... metals & mining colliery rockbolt investigation Upstream Oil & Gas floor strata Scale model study Reservoir Characterization floor heave development roadway strata deformation roof bolt longwall face slab closure roadway model strata support system 28th US Symposium on Rock...

... ABSTRACT INTRODUCTION Primarily because of mining at greater depth, an increasing number of coal mines in the United States experience floor heave problems. In many instances, the floor heaves at a slow rate without causing health and safety related problems; only additional roadway...

... ABSTRACT ABSTRACT Serious floor heave of up to 2.4 m in a 2.4-m high mine entry was eliminated by applying the stress control method of mining, as a last resort, at the No. 5 coal mine of Jim Walter Resources, Inc., in the Black Warrior coal basin near Birmingham, Alabama. Underground...

... repair required. The increasing proximity of the underlying Lower Nine Feet Seam provided few difficulties in strata control, the effects being limited to minor arch distortion with regular removal of floor heave behind the faceline. Interaction between the workings of the Four Feet and Five Feet Seams...

... of the mine. Installation of the test equipment was begun in January, 1978; all three tests were in operation by June, 1978. The overall physical makeup of each test is similar. Reservoir Characterization production logging floor heave Reservoir Surveillance radial distance production control...

... in advance of the face experience 50% more closure. Mo t of this difference is due to floor heave occurring actually in the advanced heading. Behind the faces similar area losses due to floor heave are noted in each case, but area losses due to roof movement are more pronounced with the advanced heading...

... quality Sandstone layer in a typical Coal Measures cyclothem, together with weak coal seams and seat earth bands. There was little variation in geology over the area worked. Conditions in the Main seam were generally good with minimum roof degradation and floor heave and the roadways were generally dry...