Tan Yunliang

A Modified LBM Model for Simulating Gas Seepage in Fissured Coal Considering Klinkenberg Effects and Adsorbability-Desorbability

A modified Lattice–Boltzmann method is proposed by considering the Klinkenberg effect and adsorbability-desorbability for the purpose of simulating methane gas seepage in fissured coal. The results show that the Klinkenberg effect has a little influence on methane gas seepage in fissured coal, so it can be neglected in engineering computations for simplicity. If both the Klinkenberg effect and the adsorbability-desorbability are considered, the Klinkenberg influence on gas pressure decreases as the Darcy coefficient increases. It is found by gas drainage simulations that near a drainage hole, the effect of adsorption and desorption cannot be neglected, and the location of the drainage hole has a great influence on drainage efficient λ when the hole is just located at the mid-zone of the coal seam, λ is 0.691808; when the hole is excursion down to 1.0 m from the mid-zone of coal seam, λ decreases to 0.668631; when the hole is excursion up or down to 2.0 m from the mid-zone of coal seam, λ decreases to 0.632917. The simulations supply an effective approach for optimizing the gas drainage hole location.

Notice of Retraction Creep model for Zonal disintegration of deep rock mass

Base on the Nishihara model ,change Euclid model with the Newton model , change the Newton model in Bingham model with Nonlinear viscous dampers (D model), and extend the number of the Visco-plastic model to n, so can obtain a strong rheology model, example analysis shows that this model can discribe strong rheology and obvious accelerated creep stage of deep rock, and can explain the obvious time effect of Zonal disintegration.

Influences on Pressure Releasing by Blasting Breaking Hard Roof

In order to optimize and upgrade the pressure releasing effect of blasting breaking hard roof, influence factors of it was analyzed by theoretical analysis, numerical simulation and field practice. Firstly, the impact on charge structure (charge uncoupling coefficient K, charge axial coefficient le and charge radius rb) was analyzed by indexes of fracture zone radius and crush zone radius. Secondly, the evolution trend of pressure releasing effect of different blasting parameters (angle of blasting hole, length of blasting hole and explosive charge) was studied by numerical simulation. Results show that blasting effect improves obviously with increase of charge radius and explosive charge. Reducing charge uncoupling coefficient K under the premise of using uncoupling charge ways and taking axial continuous charge way are beneficial for improving blasting effect. When the angle of blasting hole is 45° and it penetrates hard roof rock, pressure releasing effect is better. Combined with the construction equipment and materials in a mine, the charge structure and blasting parameters were designed, and a good application effect was got

Effect of weak structural layer on the zonal disintegration formation in the deep rock (The principle of the zonal disintegration formation)

Zonal disintegration has attracted the attention of many experts and scholars, also is the theoretical and practical issue to be solved in deep rock engineering. Based on the typically geological and mining conditions of Xinwen coal mine area, first, the compressive strength of rock samples which were taken from deep roadway was tested in the laboratory, and the layer thickness was identified according to compressive strength. Then, the failure characteristics were detected with strata exploring instrument. The result shows that zonal disintegration exists in surrounding rock of deep roadway, the location of fracture zone is almost the same with that of weak structural layer. When the initial stress is larger than the uniaxial compressive strength of rock in deep rock engineering, it is the external factor of zonal disintegration formation, at the same time, the weak structural layer is the internal factor.