In this paper, a numerical calculation model of the mining face was established to analyze rational size coal pillars in goaf on both sides by using FLAC3D based geological conditions pilot area. Furthermore, feasibility co-ordinated reinforcement with steel pipe column explored, which can be applied recycling residual resources like protecting and great value increase recovery rate gobs as well.

Until quite recently, the Chinese pension system was an enterprise-based, pay-as-you-go, defined benefit scheme. In 1995, the decision was made to shift to a multi-pillar scheme that included a second funded defined contribution pillar. The transition is proving difficult. This article outlines an alternative second pillar that may make more sense for China, a pay-as-you-go notional defined con...

Coal mine underground reservoir water storage technology is an effective technical way to achieve high efficiency of coal mining and protection resources. The stability pillar dam plays a decisive role in the safe stable operation reservoirs. Mining adjacent working faces long-term erosion are main influencing factors dam. In this paper, fluid-solid coupling calculation model for deformation ev...

To construct a bridge as a crossing building on a very wide river it might not used one span only, therefor, in middle of the river it is needed pillar as support. The existing of the pillars will change velocity distribution, surface water and topography of sediment, especially when the pillar is located on the bend of the river where the very large hydraulic can be hepened. Therefore, this st...

The Tashan coal mine is selected as a case study to determine the deformation and damage mechanisms of lower roadway in close-range residual pillar area. Roof drilling peephole technology applied detect roof surrounding rock. A boundary invisibility equation derived for plastic zone circular hole based on theory butterfly non-uniform stress field which principal occurs at an arbitrary angle ver...