Research On The Mechanism And Application Of Three Dimensional Anchor-cable Support For Gob-side Entry In Lu'an Mining Area

According to the movement characteristics of surrounding rock of gob-side entry, a new type three dimensional anchor-cable support technology is put forword, which can make rocks in triaxial compression and improve the integrity of surrounding rock to control the deformation by three dimensional anchor-cables with strong anchorage force in the beginning. Comprehensive use of elasto-plasticity theory and shell theory, mechanical analysis models of spatial reticulated shell structure, such as closed cylindrical shell, open cylindrical shell and stiffened cylindrical shell, are established correspond to new type three dimensional anchor-cable support. The analytic expressions of stiffened cylindrical shell stress are got through various mathematical transformation and simplification. The surrounding rock mechanical properties and effect of pressure relief by drills in laneway's side are researched by experiments, and mechanical properties and destruction features of coal samples under different confining pressures are specially discussed. The simulation test technology of three dimensional anchor-cable support for gob-side entry is firstly developed to analyze the movement characteristics of surrounding rock of gob-side entry supported by three dimensional anchor-cables, which realizes prestressed bolts and three dimensional anchor-cable support in the model. The discussion in detail about the effect of support strength, section size of roadway, relief pressure hole layout and depth of workface on the stress and deformation distribution laws of surrounding rock of gob-side entry is obtained by numerical calculation and engineering practice.