Given the deformation and instability of layered floor weakly cemented soft rock roadway, taking mining roadway Meihuajing Mine as engineering background, mechanism control measures surrounding under different stratum combination conditions are studied by using methods field investigation, numerical calculation test. The results show that: (1) characteristics in roadways significant, structure ...

Purpose. To study regularities in changes convergence of wall rocks along a setting line the powered props depending upon sandstone availability within roof, mining depth, as well its position relative to coal seam length extraction column based on results numerical experiments and forecast probable zones rigid settlement support units according longwall at any moment stope arrangement pillar a...

Aiming to reduce the high mining stress observed in large-space roof structures during mechanized mining of thick coal seams, a control technique based on protective-seam mining is proposed. This technique was used to investigate the 8108 working face of the No. 3–5 thick coal seam of the Tashan mine located in the Datong area of Shanxi, China, by means of simulations and field measurements. Th...

Green roofs are used increasingly to alleviate peaks of water discharge into the sewage systems in urban areas. Surface runoff from roofs contain pollutants from dry and wet deposition, and green roofs offer a possibility to reduce the amounts of pollutants in the water discharged from roofs by degradation and filtering. These pollutants would otherwise enter wastewater treatments plants and ul...

Quartz is a common phase in high-silica igneous rocks and is resistant to post-eruptive alteration, thus offering a reliable record of magmatic processes in silicic magma systems. Here we employ the 75 ka Toba super-eruption as a case study to show that quartz can resolve late-stage temporal changes in magmatic δ18O values. Overall, Toba quartz crystals exhibit comparatively high δ18O values, u...

characteristics of efficient roof shape is a part of configuration of efficient architecture which seems to be an ideal in contemporary architecture especially in contemporary architecture of developing countries such as iran. this study is to investigate two roof shapes in view of air flow and indoor-temperature to find efficient roofs shapes for residential buildings in tehran. computational ...

This paper is based on the condition where layered argillaceous cemented sandstone as an engineering background met by No. 207 fully mechanized working face open-off cut (Wanli 1 Coal Mine). Through mechanical theory analysis and field practice, safety problem of large-span roof supporting structure was analyzed. The caving arch height roadway in obtained mechanism instability surrounding rock ...

In view of the problems composite roof coal roadway under multiple dynamic pressure disturbances such as strong stratification, large deformation surrounding rock, and poor safety reliability, this paper analyzed instability characteristics different influencing factors using numerical simulation expounded stress distribution pattern disturbances. The geological conditions gas control in 22301 ...