Background: To optimize the layout position of residual coal pillar return roadway when mining a close seam group and to clarify optimization mechanism, analysis was conducted on Tashan mine. Methods: Surface displacement monitoring using field tests, main stress magnitude, plastic zone morphology, deformation variables, connectivity between were analyzed at different locations with help FLAC3D...

Aiming at the problem that it is difficult to achieve accurate laying of model and precise excavation roadways in special surrounding rock structure roadway according conventional physical similarity simulation, which reduces reliability experimental results. An method, named “labeling positioning drawing line, presetting model” (LPDLPRM), was proposed. The simulation deformation failure charac...

Coal is still the major resource to meet expanding energy demand and widely used in coal-fired thermal power plants taking advantage of rich reserves cost-effective production. Longwall mining a method that Türkiye, line with trend world, enables economical sustainable production underground coal resources mechanized equipment. Estimation stress distribution concentration zones excavation face ...

A pillar[5]arene dimer was synthesized by linking a mono-hydroxylated pillar[5]arene with 1,4-bis(bromomethyl)benzene. The pillar[5]arene dimer formed stronger complexes with n-alkanes than did a monomeric pillar[5]arene.

The technology described as gob-side entry driving was adopted in the Zhaogu No. 1 mine to resolve issues pertinent mining succession tension, serious roadway deformation, and support difficulties. key parameters of coal columns must be studied ensure stable effect along-air tunneling under high stress. A calculation for vertical stress a pillar is proposed, location breaking line top plate hol...

The coal pillar stress distribution at the 311102 working face in Bayangaole Mine is analyzed and revealed. In addition, borehole stressmeter, PASSAT monitoring system, numerical modelling are fully utilized. Based on patterns of acoustic wave velocity distribution, it discovered that impact created by mining activity can expand into around 40 m, where peak concentration found about 15 m ahead....