Rock dusting to prevent coal dust explosions has been in widespread use in U.S. underground coal mines since the early 1900s. Underground coal mining technology has changed significantly over this same time period, becoming highly mechanized and produces finer coal dust particles which are more explosive. Despite the advances in mining technology, mine-wide dust sampling practices have remained...

Deep-shaft mining in roadway stress concentration, difficult control of the surrounding rock, and imbalance affect efficiency coal mines. The mechanical parameters crack development law rock were studied by laboratory experiments. model was established method theoretical analysis, maximum empty roof distance deduced, two support schemes designed. Through numerical simulation method, scheme comp...

An integrated geophysical survey using both the electrical resistivity tomography (ERT) and groundpenetrating radar (GPR) methods was undertaken over a cave of great archaeological interest in southern Italy. The survey was performed to assess the stability of the carbonate rock roof of the cave. A geophysical survey was preferred to boreholes and geotechnical tests, in order to avoid the risk ...

Since the weight of overburden is sustained by both the backfill body and the unmined solid coal in coal mining with compacted backfilling (CMCB) panels, the stress and deformation characteristics of the surrounding rocks in coal mining are radically changed. The overburden movement control mechanism by coordinating with backfill body and shield in CMCB was studied systematically in this paper....

Backfill mining is an effective option to mitigate ground subsidence, especially for mining under surface infrastructure, such as buildings, dams, rivers and railways. To evaluate its performance, continual long-term field monitoring of the deformation of backfilled gob is important to satisfy strict public scrutiny. Based on industrial Ethernet, a real-time monitoring system was established to...

In order to research on stress distribution and failure depth of mining floor during the first weighting of main roof, based on the analysis of abutment pressure distribution in this case, an elastic mechanics model is established to calculate the stress of any point in the floor, expressions for this model are deduced, and meanwhile a failure criterion of floor rock is put forward according to...

Close-distance multilayer coal mining is common. Under the condition of extremely close-distance seams, it difficult to control surrounding rock large-span open-off cut roadways in multistress concentration areas. Based on engineering background 23616 roadway Chaili Coal Mine, this paper investigated influence upper close seam stress and deformation lower detail. The effect a high-strength pres...

Large and small volume rhyolites are generated in calderas and rift zones, inheriting older and isotopically diverse crystal populations from their volcanic predecessors. Low-dO values in many of these rhyolites suggest that they were derived from the remelting of solid, hydrothermally altered by meteoric water protoliths that were once close to the surface, but become buried by caldera collaps...

In the process of numerical studies, stress-strain state rock massif around mine working driven at a depth 600 m was determined. The article presents analysis distribution total vertical and horizontal stresses isolines in roof, as well ratio residual strength rocks to initial. influence roof bolting on displacement contour established. Dangerous zones near-contour preparatory were identified. ...