Study on the law of coal layer safe extraction in efflorescent oxygenized belts;

Regulars and characteristics of overlying strata in mining efflorescent oxygenized belts's coal seams;

Based on testing data in worksite and engineering practice, the strata damage movement characteristics, rock properties of weathered zone and qualitative and quantitative analysis of the mechanism of coal layer safety extraction in efflorescent oxygenized belts were discussed.

Strata behavior and control of inclined fully mechanized longwall mining face in oxidized zone of seam;

However, many problems of coal mining goaf (small coal pit and age-old sap), underneath burning area, wind oxidized zone, faultage and lava cave-in post were restricted normal production of coal mining in different degrees and moreover could bring dangerous problems.

Based on the example of the application of radial well which have satisfied the feed-water problem in a certain factory in the City of Bengbu,Anhui Province,where groundwater is meager,the paper discussed the application of radial well in aquitarde of granite-gneiss weathered zone.

During the grouting borehole drilling operation process in Yangcun Mine,in order to solve the drilling jammed and drilling tools buried problems due to the borehole falling in the weathered zone of the borehole,the surface pre-grouting construction design was optimized and the length of the second group casing pipe was extended to bellow the weathered zone.

Discussion on division principle of granite weathering zone on the site of Xiamen Jimei Bridge;

Sinopec′s approaches to the issues emerging in the new round of national CBM resources assessment, such as the low-limit depth of CBM weathering zone, CBM mineable coefficient, and reliability of CBM geological reserves, are briefly presented for the purpose of advancing CBM resources assessment in China.