We analyzed the deformation characteristics of overlying stratum in backfilling with fully-mechanized and retaining roadways along the gob area coal mining technology, and established a mechanical model for the roof k...We analyzed the deformation characteristics of overlying stratum in backfilling with fully-mechanized and retaining roadways along the gob area coal mining technology, and established a mechanical model for the roof key stratum of retaining roadways along gob under the conditions of backfilling and fully- mechanized coal mining technology. Using Winkler elastic foundation theory, we analyzed a part of the key stratum under the action of elastic foundation coupling problem, and derived deflection analyt- ical expressions. Combined with specific conditions, we obtained the deflection curves for the roof key stratum of retaining roadways along gob under the conditions of backfilling and fully-mechanized coal mining technology. On this basis, we adopted the Coulomb's earth pressure theory to solve the problem of lateral pressure of the gangue filling area on the supporting wall beside the roadway and to provide the theoretical basis for reasonable selection of the distance between gangue concrete wall and roof and fur- ther discussion on the supporting stability of roadway.展开更多
Obtaining petroleum at the cost of electrical energy is a common problem in almost all oil fields, and it is mainly caused by low duty radio of induction motor used in beam pumping units. Traditional beam-pumping unit...Obtaining petroleum at the cost of electrical energy is a common problem in almost all oil fields, and it is mainly caused by low duty radio of induction motor used in beam pumping units. Traditional beam-pumping units have many intrinsic disadvantages such as low efficiency, complex transmission devices, poor flexibility, tremendous volume and weight in long stroke, etc.Therefore, a novel direct driven linear electromagnetic pumping unit (EMPU) has been developed by combining oil extraction technology with linear motor technology. The thrust of EMPU matches the changing of suspension center load to improve the system efficiency and cut down the consumption of energy. Based on previous experience, a small-scale prototype was developed and a simulation was conducted with it. Both theoretical analyses and experimental study showed that the problems exiting in beam pumping units can be solved with EMPU system, and this is a new method which can be used to solve high energy waste in oil fields.展开更多
When mining the fully-mechanized longwall caving face along strike, the unstable equipment, the low top-coal recovery ratio and the difficulty in controlling surrounding rock may occur due to large dip angle. Consider...When mining the fully-mechanized longwall caving face along strike, the unstable equipment, the low top-coal recovery ratio and the difficulty in controlling surrounding rock may occur due to large dip angle. Considering the effects of strike angle on support stability, the ‘‘support-surrounding rock"mechanical models of support topple and support slip were established in this paper. On the basis, the influencing factors of support stability were analyzed and the technical measures of controlling support and surrounding rock stability were put forward. Then the loose particles simulation experiment was conducted to analyze the impacts of caving directions and methods on the top-coal recovery in large dip angle fully-mechanized caving face. Finally, the ‘‘upward sequence and double-openings doublerounds" caving technology was determined. The research results are of great scientific significance and practical values to improve large dip thick seam mining technology.展开更多
Based on the movement regularity of surrounding rock with road-in packing of gob-side entry retaining in fully-mechanized sub-level caving face(RPGERFCF),the me- chanical model of its surrounding rock was established ...Based on the movement regularity of surrounding rock with road-in packing of gob-side entry retaining in fully-mechanized sub-level caving face(RPGERFCF),the me- chanical model of its surrounding rock was established and the calculating formulas of the deformation of the roof,coal wall and filling body were attained.By the mechanical analy- sis to the deformation of the surrounding rock of RPGERFCF,the major factors influencing the deformation of the surrounding rock were found out and the technologic approaches reduced the deformation and enhanced the stability of the surrounding rock were put for- ward.Consequently,the scientific bases were provided for the stability control of the sur- rounding rock of RPGERFCF.展开更多
Combined with the 3D FEM,end-anchored anchorage bolts were simulated by implicit anchorage bolt element.Implicit anchorage bolt elements hide in the elements of rock mass and extremely simplify the element subdivision...Combined with the 3D FEM,end-anchored anchorage bolts were simulated by implicit anchorage bolt element.Implicit anchorage bolt elements hide in the elements of rock mass and extremely simplify the element subdivision.The calculated value of an- chorage bolt stress is larger than the measured one for the most time.we further analyzed the reciprocity of anchorage bolt and rock mass,and then deduced the analytical equa- tions of anchorage bolt stress and rock mass deformation under elasto-plastic state.The results indicate that it is essential to revise the anchorage bolts stress by using the formu- las deduced when rock mass is softened or significantly deformed.Finally,a case study indicates that the calculated results agree with those measured.Some helpful methods are offerd for more accurate simulation of the support effect and anchorage bolts real stress state.展开更多
In order to recover ore as much as possible, a computer-controlled truck real-time dispatching model is conducted under the conditions of Qidashan lron Mine. It can not only acquire the optimization of shovel and truc...In order to recover ore as much as possible, a computer-controlled truck real-time dispatching model is conducted under the conditions of Qidashan lron Mine. It can not only acquire the optimization of shovel and truck operation, but also satisfy requirements of blending ores.The simulation results indicate the effectiveness of the model developed.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 51074163 and 50834005)the Ministry of Education Support Program for New Century Excellent of China(No. NCET-08-0837)the Fundamental Research Funds for the Central Universities of China
文摘We analyzed the deformation characteristics of overlying stratum in backfilling with fully-mechanized and retaining roadways along the gob area coal mining technology, and established a mechanical model for the roof key stratum of retaining roadways along gob under the conditions of backfilling and fully- mechanized coal mining technology. Using Winkler elastic foundation theory, we analyzed a part of the key stratum under the action of elastic foundation coupling problem, and derived deflection analyt- ical expressions. Combined with specific conditions, we obtained the deflection curves for the roof key stratum of retaining roadways along gob under the conditions of backfilling and fully-mechanized coal mining technology. On this basis, we adopted the Coulomb's earth pressure theory to solve the problem of lateral pressure of the gangue filling area on the supporting wall beside the roadway and to provide the theoretical basis for reasonable selection of the distance between gangue concrete wall and roof and fur- ther discussion on the supporting stability of roadway.
文摘Obtaining petroleum at the cost of electrical energy is a common problem in almost all oil fields, and it is mainly caused by low duty radio of induction motor used in beam pumping units. Traditional beam-pumping units have many intrinsic disadvantages such as low efficiency, complex transmission devices, poor flexibility, tremendous volume and weight in long stroke, etc.Therefore, a novel direct driven linear electromagnetic pumping unit (EMPU) has been developed by combining oil extraction technology with linear motor technology. The thrust of EMPU matches the changing of suspension center load to improve the system efficiency and cut down the consumption of energy. Based on previous experience, a small-scale prototype was developed and a simulation was conducted with it. Both theoretical analyses and experimental study showed that the problems exiting in beam pumping units can be solved with EMPU system, and this is a new method which can be used to solve high energy waste in oil fields.
基金provided by the National Key Basic Research Program of China (973 Program) (No. 2015CB251600)the Qing Lan Projectthe Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘When mining the fully-mechanized longwall caving face along strike, the unstable equipment, the low top-coal recovery ratio and the difficulty in controlling surrounding rock may occur due to large dip angle. Considering the effects of strike angle on support stability, the ‘‘support-surrounding rock"mechanical models of support topple and support slip were established in this paper. On the basis, the influencing factors of support stability were analyzed and the technical measures of controlling support and surrounding rock stability were put forward. Then the loose particles simulation experiment was conducted to analyze the impacts of caving directions and methods on the top-coal recovery in large dip angle fully-mechanized caving face. Finally, the ‘‘upward sequence and double-openings doublerounds" caving technology was determined. The research results are of great scientific significance and practical values to improve large dip thick seam mining technology.
基金the National Science Foundation of China(50674046)National Science Important Foundation(50634050)Hunan Science Foundation(06JJ50092)
文摘Based on the movement regularity of surrounding rock with road-in packing of gob-side entry retaining in fully-mechanized sub-level caving face(RPGERFCF),the me- chanical model of its surrounding rock was established and the calculating formulas of the deformation of the roof,coal wall and filling body were attained.By the mechanical analy- sis to the deformation of the surrounding rock of RPGERFCF,the major factors influencing the deformation of the surrounding rock were found out and the technologic approaches reduced the deformation and enhanced the stability of the surrounding rock were put for- ward.Consequently,the scientific bases were provided for the stability control of the sur- rounding rock of RPGERFCF.
文摘Combined with the 3D FEM,end-anchored anchorage bolts were simulated by implicit anchorage bolt element.Implicit anchorage bolt elements hide in the elements of rock mass and extremely simplify the element subdivision.The calculated value of an- chorage bolt stress is larger than the measured one for the most time.we further analyzed the reciprocity of anchorage bolt and rock mass,and then deduced the analytical equa- tions of anchorage bolt stress and rock mass deformation under elasto-plastic state.The results indicate that it is essential to revise the anchorage bolts stress by using the formu- las deduced when rock mass is softened or significantly deformed.Finally,a case study indicates that the calculated results agree with those measured.Some helpful methods are offerd for more accurate simulation of the support effect and anchorage bolts real stress state.
文摘In order to recover ore as much as possible, a computer-controlled truck real-time dispatching model is conducted under the conditions of Qidashan lron Mine. It can not only acquire the optimization of shovel and truck operation, but also satisfy requirements of blending ores.The simulation results indicate the effectiveness of the model developed.
