In order to reveal the influence law of coal seam dip angle on stability surrounding rock gob-side coal–rock roadway in a gently inclined (GCRGICS), deformation characteristics under four different angles this kind were studied by field investigation, theoretical analysis and numerical simulation. The results showed that, with increase angle, amount roof subsidence upper lower side arc triangle...

The occurrence of rockburst in coal mines is closely related to the stress and rock mass. Through hydraulic fracturing measurements roof, three-dimensional roof before after as well during working face advancing was monitored, effect on controlling studied. test results show that (1) fracturing, three principal stresses decreased remarkably, whose maximum reduction about 20%, while elastic stra...

Numerous studies have identified the roof plate as an important signaling center controlling dorsal interneuron specification and differentiation in the developing spinal cord. Currently, the molecular pathways of roof plate formation and function are poorly understood. We determined that the LIM-homeodomain transcription factor Lmx1b is sufficient to induce functional roof plate in the early c...

The stability of composite material that is composed roof rock, cemented paste backfill (CPB), and floor rock has an important impact on safe mining within metal mines. In order to explore the mechanical properties, acoustic emission (AE), energy dissipation, damage evolution roof–CPB–floor (RCF) layered materials, uniaxial compression (loading rate 0.02 mm/min) AE tests RCF materials with diff...

Roof bolting is the most popular type of support for underground mines’ workings. However, in Polish coal mines it used only as a supplementary support. To raise effectiveness and economic score horizontal development works, JSW (Jastrzębska Spółka Węglowa) started project to introduce independent rock its mines. The key element monitoring mine workings supported with roof bolting, appropriate ...

For deep-buried thick top-coal roadways under high stress, there exists great difficulty in controlling the stability of surrounding rock as well necessity for low driving speeds. Taking return air roadway 20201 (RAR 20201) Dahaize Coal Mine background, this paper presents a typical engineering case western mine. Through methods such situ investigation, theoretical analysis, numerical simulatio...

In response to the large-scale instability failure problem of designing coal pillars and support systems for gob-side entry driving (GSED) in high-stress soft seams deep mines, main difficulties surrounding rock control GSED were analyzed. The relationship between position roof breaking line, together with width limit equilibrium zone a reasonable size pillar, quantified through theoretical cal...

Improving coal resource mining rates has long been a focus of industry research. The gob-side entry retaining by roof cutting (GERRC) is new technology that gained popularity in China due to its high rate and safety. Based on the GERRC technology, precise technical procedure elaborated, fundamental idea pressure relief explored through creating structural mechanics model surrounding rock this p...

The compaction and consolidation process of a regenerated roof can be divided into two stages, namely, secondary fragmentation crushed rock masses pore structure adjustment. Therefore, the mechanical properties differs significantly from those primary roof. We performed confined compression tests mudstones sandy using self-developed testing apparatus. studied influence moisture content, ratio, ...

This paper is addressed to an approach for segmenting airborne laser scanning point cloud. It aims to detect and cluster point cloud of an input roof into several segments that are corresponding to plane patches of the roof. The algorithm is developed based on the assumption that every non-flat roof can be decomposed into a set of gabled and/or hipped roof. The process detects roof ridges at fi...