Based on the basic theory of gas seepage and coal seam deformation, using the numerical simulation method, this paper established the gas-solid coupling model of gas drainage from borehole. Using multi-physical coupli...Based on the basic theory of gas seepage and coal seam deformation, using the numerical simulation method, this paper established the gas-solid coupling model of gas drainage from borehole. Using multi-physical coupling analysis software, the authors studied the stress change conditions around the drainage borehole, the influence of the gas drainage effect caused by the drilling gap, and the gas drainage effect under the conditions of different borehole radius and different permeabilities. The results show that the effective drainage radius is 1.03 m during 30 days of drainage. The effect of the diameter change of the drainage borehole is limited, but the influence of coal seam permeability is much bigger. After the same drainage period, the greater the permeability of coal seam is, the bigger the drainage radius is. For a low permeability coal seam, coal miners should take pressure-relief measures and increase the permeability to improve the drainage effects before draining gas through drilling.展开更多
Based on the equation of the gas flow continuity and state, Darcy law and Langmuir equation, the law of methane seepage in the wall of drainage roadway was studied. The governing equation of methane one-way seepage in...Based on the equation of the gas flow continuity and state, Darcy law and Langmuir equation, the law of methane seepage in the wall of drainage roadway was studied. The governing equation of methane one-way seepage in the seam was founded. By solving the equation, the calculation of methane seepage velocity in the coal wall was worked out. The result has really applied worth and will give beneficial references to re-lated research, it provides preventing coal and gas outbursts with theoretical gist.展开更多
To meet the demand of urban rainwater integrated management,we designed and complemented a physical simulation experimental system of urban rainfall infiltration regulation parameters.We discuss the feasibility of qua...To meet the demand of urban rainwater integrated management,we designed and complemented a physical simulation experimental system of urban rainfall infiltration regulation parameters.We discuss the feasibility of quantitative regulations of urban underlying surface rainfall infiltration conditions and a practical application of a simulated experimental system.In a com- prehensive analysis of the composition of an effective rainwater harvesting system and selection of water storage material,we simulated the major parameters of an experimental area rainfall,soil moisture and water storage capacity by providing an effective regulation of the experimental area runoff coefficient,obtained from basic data.展开更多
This paper presents the one-dimensional(1D)viscoelastic consolidation system of saturated clayey soil under continuous drainage boundaries.The fractional-derivative Merchant(FDM)model has been introduced into the cons...This paper presents the one-dimensional(1D)viscoelastic consolidation system of saturated clayey soil under continuous drainage boundaries.The fractional-derivative Merchant(FDM)model has been introduced into the consolidation system to simulate the viscoelasticity.Swartzendruber’s flow law is also introduced to describe the non-Darcian flow characteristics simultaneously.The generalized numerical solution of the 1D consolidation under continuous boundaries is given by the finite difference scheme.Furthermore,to illustrate the effectiveness of the numerical method,two simplified cases are compared against the current analytical and numerical results.Finally,the effects of boundary parameters and model parameters on the viscoelastic consolidation were illustrated and discussed.The results indicated that the boundary parameters have a significant influence on consolidation.The larger the values of boundary parameters,the faster the whole dissipation of the excess pore-water pressure and soils’settlement rate.Fractional-order and viscosity parameter have little effect on consolidation,which are primarily significant in the middle and late consolidation phases.With the increase of the modulus ratio,the whole consolidation process becomes faster.Moreover,considering Swartzendruber’s flow delays the consolidation rate of the soil layer.展开更多
Fifty-six cases of the protrusion of the lumbar intervertebral disc in the treatment group were treated by drug-penetration and oral administration of traditional Chinese decoction plus traction, and the other 35 case...Fifty-six cases of the protrusion of the lumbar intervertebral disc in the treatment group were treated by drug-penetration and oral administration of traditional Chinese decoction plus traction, and the other 35 cases in the control group by oral administration of Chinese decoction and traction. The results showed that the cure rate in the treatment group was 83.9%, and that in the control group was 57.1%, with a statistically significant difference between the two groups (P<0.01), indicating that the former is a more effective therapy for protrusion of the lumbar intervertebral disc.展开更多
基金Supported by the National Natural Science Foundation of China （51174212） the Program for New Century Excellent Talents in University of China （NCET-10-0724） the Fundamental Research Funds for the Central Universities （2010QZ05）
文摘Based on the basic theory of gas seepage and coal seam deformation, using the numerical simulation method, this paper established the gas-solid coupling model of gas drainage from borehole. Using multi-physical coupling analysis software, the authors studied the stress change conditions around the drainage borehole, the influence of the gas drainage effect caused by the drilling gap, and the gas drainage effect under the conditions of different borehole radius and different permeabilities. The results show that the effective drainage radius is 1.03 m during 30 days of drainage. The effect of the diameter change of the drainage borehole is limited, but the influence of coal seam permeability is much bigger. After the same drainage period, the greater the permeability of coal seam is, the bigger the drainage radius is. For a low permeability coal seam, coal miners should take pressure-relief measures and increase the permeability to improve the drainage effects before draining gas through drilling.
文摘Based on the equation of the gas flow continuity and state, Darcy law and Langmuir equation, the law of methane seepage in the wall of drainage roadway was studied. The governing equation of methane one-way seepage in the seam was founded. By solving the equation, the calculation of methane seepage velocity in the coal wall was worked out. The result has really applied worth and will give beneficial references to re-lated research, it provides preventing coal and gas outbursts with theoretical gist.
基金Projects 40371113 supported by the National Natural Science Foundation of ChinaOF060096 by the Youth Scientific Foundation of China University of Mining & Technology
文摘To meet the demand of urban rainwater integrated management,we designed and complemented a physical simulation experimental system of urban rainfall infiltration regulation parameters.We discuss the feasibility of quantitative regulations of urban underlying surface rainfall infiltration conditions and a practical application of a simulated experimental system.In a com- prehensive analysis of the composition of an effective rainwater harvesting system and selection of water storage material,we simulated the major parameters of an experimental area rainfall,soil moisture and water storage capacity by providing an effective regulation of the experimental area runoff coefficient,obtained from basic data.
基金Projects(51879104,52078206)supported by the National Natural Science Foundation of China。
文摘This paper presents the one-dimensional(1D)viscoelastic consolidation system of saturated clayey soil under continuous drainage boundaries.The fractional-derivative Merchant(FDM)model has been introduced into the consolidation system to simulate the viscoelasticity.Swartzendruber’s flow law is also introduced to describe the non-Darcian flow characteristics simultaneously.The generalized numerical solution of the 1D consolidation under continuous boundaries is given by the finite difference scheme.Furthermore,to illustrate the effectiveness of the numerical method,two simplified cases are compared against the current analytical and numerical results.Finally,the effects of boundary parameters and model parameters on the viscoelastic consolidation were illustrated and discussed.The results indicated that the boundary parameters have a significant influence on consolidation.The larger the values of boundary parameters,the faster the whole dissipation of the excess pore-water pressure and soils’settlement rate.Fractional-order and viscosity parameter have little effect on consolidation,which are primarily significant in the middle and late consolidation phases.With the increase of the modulus ratio,the whole consolidation process becomes faster.Moreover,considering Swartzendruber’s flow delays the consolidation rate of the soil layer.
文摘Fifty-six cases of the protrusion of the lumbar intervertebral disc in the treatment group were treated by drug-penetration and oral administration of traditional Chinese decoction plus traction, and the other 35 cases in the control group by oral administration of Chinese decoction and traction. The results showed that the cure rate in the treatment group was 83.9%, and that in the control group was 57.1%, with a statistically significant difference between the two groups (P<0.01), indicating that the former is a more effective therapy for protrusion of the lumbar intervertebral disc.
