The first topic discussed in this paper is to evaluate the present supporting theories,among which the typical two are collapse arch and elasto-plastic theories. The former is rather limited in practical application,a...The first topic discussed in this paper is to evaluate the present supporting theories,among which the typical two are collapse arch and elasto-plastic theories. The former is rather limited in practical application,and the latter is built up on some assumptions which is inconsis-tent with the reality,for it is of no need to support a roadway of which the surrounding rock is in elasto-plastic state. The second topic is to prove the objective existence of the broken zone in surrounding rock(BZSR) by a series of laboratory experiments and field measurements. The paper indicates that the object to be supported mainly is the bulking or expanding force resulted from the development of BZSR. This is remarkably different from the existing points of view which have been generally recognized nowadays. So far ,this theory has been tested in supporting more than ten thousand meters roadways located in various strata and has proved itself to have a great technoeconomical benefit.展开更多
According to the practical conditions of coal roadway in Changcun Coal Mine of Lu＇an Mining Group, the deformation of rock surrounding roadway was experimentally studied by means of thermal infrared （TIP,） imaging ...According to the practical conditions of coal roadway in Changcun Coal Mine of Lu＇an Mining Group, the deformation of rock surrounding roadway was experimentally studied by means of thermal infrared （TIP,） imaging system in the process of confined compressions. It is found that the model surface TIR temperature （TIRT） changes with the increase of load. Furthermore, TIRT changes non-synchronously in different ranges such as the roof, floor, wall, corners and bolted ranges. The TIRT is higher in the location of stress concentration and bolted ranges than that in the location of stress relaxation and broken ranges. The interaction ranges of bolt and rock are determined preliminarily according to the corresponding relationship of TIRT fields and the strain fields of the surrounding rock. The new method of TIR image processing has been proved to be effective for the study of bolt support and observation of roadway stability under mine pressure.展开更多
For the engineering geology conditions of bad mine roadway roof and floor lithology in extremely weak cemented strata, the best section shape of the roadway is determined from the study of tunnel surrounding rock disp...For the engineering geology conditions of bad mine roadway roof and floor lithology in extremely weak cemented strata, the best section shape of the roadway is determined from the study of tunnel surrounding rock displacement, plastic zone and stress distribution in rectangular, circle arch and arch wall sections, respectively. Based on the mining depth and thickness of the coal seam, roadway support technology solutions with different buried depth and thickness of coal seam are proposed. Support schemes are amended and optimized in time through monitoring data of the deformation of roadway, roof separation, l-beam bracket, bolt and anchor cable force to ensure the long-term stability and security of the roadway surrounding rock and support structure. The monitoring results show that mine roadway support schemes for different buried depth and section can be adapted to the characteristics of ground pressure and deformation of the surrounding rock in different depth well, effectively control the roadway surrounding rock deformation and the floor heave and guarantee the safety of construction and basic stability of surrounding rock and support structure.展开更多
This paper analyzed the strata behaviors of solid-coal roadway, gob-side entry driving and deformation law of surrounding rock in depth under high stress and thick composite roof based on the dynamic pressure roadway ...This paper analyzed the strata behaviors of solid-coal roadway, gob-side entry driving and deformation law of surrounding rock in depth under high stress and thick composite roof based on the dynamic pressure roadway as engineering background in Fengcheng mining area, Jiangxi province. The results, both field measurement and numerical simulation show that gob-side entry driving results the deformation of coal roadway main wall, however, entity-coal roadway driving results deformation of main roof and floor. The maintenance state of gob-side entry driving is better than entity-coal roadway, this situation is relevant to thick composite roof layered and easy collapse characteristics. At the same time, this paper put fox＇ward and proved proper dynamic pressure roadway supporting scheme under the surrounding rock condition and stress environment.展开更多
The run-around of Xiagou subincline bottom is a soft rock roadway, its floor has heaved over 1 m. ln this paper, by electronic microscope scanning and X-ray diffraction analy-sis, the components of the soft rock are d...The run-around of Xiagou subincline bottom is a soft rock roadway, its floor has heaved over 1 m. ln this paper, by electronic microscope scanning and X-ray diffraction analy-sis, the components of the soft rock are determined and the breaking mechanism of roadway is analyzed as well. Through finite element calculation and simulation model test, the reasonable repair support method is put forward.展开更多
Roadway surrounding rock is a compound structure consisted of roof, floor and sides. The sides of extraction opening is the weak coal mass, which affect immediately the stability of floor. It was simulated by numerica...Roadway surrounding rock is a compound structure consisted of roof, floor and sides. The sides of extraction opening is the weak coal mass, which affect immediately the stability of floor. It was simulated by numerical calculation for the strength of sides coal to affect the floor heave, the higher strength of sides coal is, the lower degree of floor heave was. So it was put forward reinforcing sides to control floor heave of extraction opening, and it was proved by engineering practice that the floor heave of deep extraction opening can be controlled to a certain degree by reinforcing sides of roadway.展开更多
A typical gateway is analyzed using fully-deformable discrete element method. The fractured zone around the gateway is measured in field. Based on the measurement results and theoretical analysis, a comprehensive supp...A typical gateway is analyzed using fully-deformable discrete element method. The fractured zone around the gateway is measured in field. Based on the measurement results and theoretical analysis, a comprehensive support scheme adopting bolt and steel belt is proposed. Discrete element method is used to assess the bolting scheme, and displacement monitoring in field is also carried out. Having been put into practice, it is proved that the scheme is both successful and rational. According to theoretical analysis and monitoring in field, some important keynotes that should be noticed in gateway bolting practice are presented as well.展开更多
Ground stress is the fundamental cause of deformation and failure during underground structural engineering. Field stress measurements in the main coal bed in the Lueliang mining area were made by the bore hole, stres...Ground stress is the fundamental cause of deformation and failure during underground structural engineering. Field stress measurements in the main coal bed in the Lueliang mining area were made by the bore hole, stress relief method. From these data the ground stress distribution of the mining area was obtained. The relationship between the horizontal principal stress and the deformation and failure of a roadway is discussed with an engineering example. The results indicate that horizontal stress dominates in the shallow crust in the Ltiliang mining area. Roadways at different angles to the maximum principal stress have different levels of stress concentration. This leads to a significant difference in stability of the corresponding roadways. These research results provide an important criterion for determining roadway position and direction, stope layout, and roadway support design.展开更多
The mechanical principle and surrounding rock deformation feature of highstress coal roadway was analyzed.The condition of stress balance of the kind of theroadway was put forward.The surrounding rock control principl...The mechanical principle and surrounding rock deformation feature of highstress coal roadway was analyzed.The condition of stress balance of the kind of theroadway was put forward.The surrounding rock control principle and supporting techniqueof high stress coal roadway were discussed.It was very important to control early daysdeformation of coal sides.The supporting strength is should increased,so the strengthloss of coal sides is decreased.The range of plastic fluid zone is reduced.The abovemention-ned principle is applied in industrial test,and the new supporting technique is ap-plied successfully.展开更多
文摘The first topic discussed in this paper is to evaluate the present supporting theories,among which the typical two are collapse arch and elasto-plastic theories. The former is rather limited in practical application,and the latter is built up on some assumptions which is inconsis-tent with the reality,for it is of no need to support a roadway of which the surrounding rock is in elasto-plastic state. The second topic is to prove the objective existence of the broken zone in surrounding rock(BZSR) by a series of laboratory experiments and field measurements. The paper indicates that the object to be supported mainly is the bulking or expanding force resulted from the development of BZSR. This is remarkably different from the existing points of view which have been generally recognized nowadays. So far ,this theory has been tested in supporting more than ten thousand meters roadways located in various strata and has proved itself to have a great technoeconomical benefit.
基金Projects 50374069 supported by National Natural Science Foundation of China and 2002CB412701 supported by 973 of China
文摘According to the practical conditions of coal roadway in Changcun Coal Mine of Lu＇an Mining Group, the deformation of rock surrounding roadway was experimentally studied by means of thermal infrared （TIP,） imaging system in the process of confined compressions. It is found that the model surface TIR temperature （TIRT） changes with the increase of load. Furthermore, TIRT changes non-synchronously in different ranges such as the roof, floor, wall, corners and bolted ranges. The TIRT is higher in the location of stress concentration and bolted ranges than that in the location of stress relaxation and broken ranges. The interaction ranges of bolt and rock are determined preliminarily according to the corresponding relationship of TIRT fields and the strain fields of the surrounding rock. The new method of TIR image processing has been proved to be effective for the study of bolt support and observation of roadway stability under mine pressure.
基金Financial support for this work, provided by the Major Program of the National Natural Science Foundation of China (Nos. 51174196 and 51204168)the Program for New Century Excellent Talents in University by Ministry of Education of China (No. NCET-07-0519)
文摘For the engineering geology conditions of bad mine roadway roof and floor lithology in extremely weak cemented strata, the best section shape of the roadway is determined from the study of tunnel surrounding rock displacement, plastic zone and stress distribution in rectangular, circle arch and arch wall sections, respectively. Based on the mining depth and thickness of the coal seam, roadway support technology solutions with different buried depth and thickness of coal seam are proposed. Support schemes are amended and optimized in time through monitoring data of the deformation of roadway, roof separation, l-beam bracket, bolt and anchor cable force to ensure the long-term stability and security of the roadway surrounding rock and support structure. The monitoring results show that mine roadway support schemes for different buried depth and section can be adapted to the characteristics of ground pressure and deformation of the surrounding rock in different depth well, effectively control the roadway surrounding rock deformation and the floor heave and guarantee the safety of construction and basic stability of surrounding rock and support structure.
基金Supported by the National Natural Science Foundation of China （51074071） the Scientific Research Fund of Hunan Provincial Education Department （12cy013）
文摘This paper analyzed the strata behaviors of solid-coal roadway, gob-side entry driving and deformation law of surrounding rock in depth under high stress and thick composite roof based on the dynamic pressure roadway as engineering background in Fengcheng mining area, Jiangxi province. The results, both field measurement and numerical simulation show that gob-side entry driving results the deformation of coal roadway main wall, however, entity-coal roadway driving results deformation of main roof and floor. The maintenance state of gob-side entry driving is better than entity-coal roadway, this situation is relevant to thick composite roof layered and easy collapse characteristics. At the same time, this paper put fox＇ward and proved proper dynamic pressure roadway supporting scheme under the surrounding rock condition and stress environment.
文摘The run-around of Xiagou subincline bottom is a soft rock roadway, its floor has heaved over 1 m. ln this paper, by electronic microscope scanning and X-ray diffraction analy-sis, the components of the soft rock are determined and the breaking mechanism of roadway is analyzed as well. Through finite element calculation and simulation model test, the reasonable repair support method is put forward.
基金Supported by Hunan Nature Science Foundation(04JJY3113)
文摘Roadway surrounding rock is a compound structure consisted of roof, floor and sides. The sides of extraction opening is the weak coal mass, which affect immediately the stability of floor. It was simulated by numerical calculation for the strength of sides coal to affect the floor heave, the higher strength of sides coal is, the lower degree of floor heave was. So it was put forward reinforcing sides to control floor heave of extraction opening, and it was proved by engineering practice that the floor heave of deep extraction opening can be controlled to a certain degree by reinforcing sides of roadway.
文摘A typical gateway is analyzed using fully-deformable discrete element method. The fractured zone around the gateway is measured in field. Based on the measurement results and theoretical analysis, a comprehensive support scheme adopting bolt and steel belt is proposed. Discrete element method is used to assess the bolting scheme, and displacement monitoring in field is also carried out. Having been put into practice, it is proved that the scheme is both successful and rational. According to theoretical analysis and monitoring in field, some important keynotes that should be noticed in gateway bolting practice are presented as well.
基金supported by the National Natural Science Foundation of China (No. 50874103)the National Basic Research Program of China (No. 2010CB226805)+1 种基金the Natural Science Foundation of Jiangsu Province (No. BK2008135)the Open Foundation of State Key Laboratory of Geomechanics and Deep Underground Engineering (No. SKLGDUEK0905)
文摘Ground stress is the fundamental cause of deformation and failure during underground structural engineering. Field stress measurements in the main coal bed in the Lueliang mining area were made by the bore hole, stress relief method. From these data the ground stress distribution of the mining area was obtained. The relationship between the horizontal principal stress and the deformation and failure of a roadway is discussed with an engineering example. The results indicate that horizontal stress dominates in the shallow crust in the Ltiliang mining area. Roadways at different angles to the maximum principal stress have different levels of stress concentration. This leads to a significant difference in stability of the corresponding roadways. These research results provide an important criterion for determining roadway position and direction, stope layout, and roadway support design.
基金National Natural Science Foundation(50674045)Youth Project of Hunan Education Office(04B020)
文摘The mechanical principle and surrounding rock deformation feature of highstress coal roadway was analyzed.The condition of stress balance of the kind of theroadway was put forward.The surrounding rock control principle and supporting techniqueof high stress coal roadway were discussed.It was very important to control early daysdeformation of coal sides.The supporting strength is should increased,so the strengthloss of coal sides is decreased.The range of plastic fluid zone is reduced.The abovemention-ned principle is applied in industrial test,and the new supporting technique is ap-plied successfully.
