To meet the differential needs of the surrounding rock controlling effect of hydraulic support for different coal seams, we calculate the preference coefficient matrix of the different evaluation indicators.
Based on the independently researched and developed longwall mining working face supporting quality monitoring system, we identify the six controllable parameters of hydraulic support to surrounding rock through many field observations of hydraulic support and surrounding rock.
The determination on the working resistance force of hydraulic support for LLTCC mining in ultra-thick coal seams: (1) Based on criteria of immediate roof.
The tonnage of hydraulic support for the working face in thick and ultra-thick coal seam is very large.
Therefore, based on the geotechnical conditions of rock strata at the Tashan coal mine, the working resistance force of hydraulic support for the No. 8105 LLTCC face at ultra-thick coal seam in Tashan coal mine was determined as 15,000 kN.
The requirements for hydraulic support consist of rational structure, sufficient support resistance force, stable and shock resistance, sustainability of high efficient coal discharge and high coal recovery.
On-site experiment proves that the periodic weighting step interval of the caving face is 15 16 m, which is basically consistent with the theoretical analysis results, and indicates that the mechanized caving hydraulic support is capable of meeting the support requirements in the mining of a super-thick but shallowly buried coal seam.
Based on the coupling characteristic between mining-induced stress field and supporting stress field of hydraulic support, we identify six controllable factors in the application of hydraulic support to surrounding rock, and further reveal the relationship between hydraulic support and surrounding rock in terms of the strength, the stiffness, and the stability coupling.
Figure 14 shows that the distribution of working resistance of hydraulic support was rational, and appeared as a distribution of sine wave.
Hydraulic support is one of key equipment for a LLTCC coal mining operation.
