Abstract: An NPR non-magnetic steel material for rock bolt and a production method thereof are disclosed. The NPR non-magnetic steel material for rock bolt has a composition, in weight percent, consisting of: C: 0.4-0.7%, Mn: 15-20%, Cr: 1-18%, Si: 0.3-3%, Ca: 0.05-0.15%, Cu: ?0.03%, Ni: ?0.02%, S: ?0.001%, P: ?0.001%, and the rest being Fe and unavoidable impurity elements. The NPR non-magnetic steel material for rock bolt and the production method thereof effectively solve the problems of steel materials for rock bolt in the prior art such as strong magnetism, low tensile strength and low effective elongation. The NPR non-magnetic steel material for rock bolt has a fully-austenitized structure and is non-magnetic, its yield strength is adjustable in the range of 600-1000 MPa, and its elongation is adjustable in the range of 20-60%.

Abstract: An equipment system for a self-retaining mining method mainly comprises a transition support, an end support, a following support, and a fast-retracting support. Working face gateroads do not need to advance in mining, and a coal mining machine may be used to cut a neat coal wall at the end of a district. The entry rib is automatically formed after roof caving, thus forming a gateroad in a re-mining process. The coal mining machine is under digital control when its end cuts the coal, automatically enabling the end to laterally cut the coal wall to form a vertical straight line, which is used as the entry rib of the gateroad. A scrapper conveyor works in coordination with an arc-shaped coal grabbing plate of the coal mining machine to clean up float coal at the end as much as possible.

Abstract: An NPR steel material for rock bolt and a production method thereof are disclosed. The NPR steel material for rock bolt has a composition, in weight percent, consisting of: C: 0.4-0.7%, Mn: 15-20%, Si: ?0.1%, Cu: ?0.03%, Cr: ?0.01%, Ni: ?0.02%, S: ?0.001%, P: ?0.001%, and the rest being Fe and unavoidable impurity elements. The NPR steel material for rock bolt and the production method thereof effectively solve the problem that rock bolts in the prior art have low tensile strength and low effective elongation. The NPR steel material for rock bolt has a yield strength adjustable in the range of 500-1100 MPa, and an elongation adjustable in the range of 10-80%.

Abstract: A fractured roof 110 mining method entry-side anti-collapsed structure, one working face of the 110 mining method corresponds to one roadway but without retaining any coal pillar, the roadway retains an entry after the previous working face implements mining top-cutting pressure release, and a roof of the roadway is arch-shape, directional cutting is conducted on one side of the roadway, and the cutting angle is between 15-20 degrees. One working face corresponds to one roadway but without retaining any coal pillar when underground mining is conducted, which can save resources and improve recovery rate of mining. And, the roof of the roadway of the retained entry is arch-shaped, which can improve safety and ensure safety of the coal mining working face. In addition, a cutting angle is 15-20 degrees, which can effectively determine a roof caving direction after top-cutting and reduce affect to the retained entry.

Abstract: A longwall N00 mining method includes performing a no-entry excavation and non-pillar mining in N working faces of a new district, and the whole district is provided with an air-return dip, a haulage dip and a track dip, wherein the air-return dip and the track dip are located on one end of the district, and the haulage dip is connected to the other end of the district, and connected to the air-return dip. This method can not only ensure ventilation of the whole coal cutting are, but also when mining is performed in each working face in the district, entries can be automatically formed due to top-cutting pressure release by using a part of a gob area, and thereby it is not required to separately excavate any gateroad entry during mining coal nor need to retain any coal pillar, so as to save resources and improve efficiency.

Abstract: A fractured roof 110 mining method entry-side anti-collapsed structure, one working face of the 110 mining method corresponds to one roadway but without retaining any coal pillar, the roadway retains an entry after the previous working face implements mining top-cutting pressure release, and a roof of the roadway is arch-shape, directional cutting is conducted on one side of the roadway, and the cutting angle is between 15-20 degrees. One working face corresponds to one roadway but without retaining any coal pillar when underground mining is conducted, which can save resources and improve recovery rate of mining. And, the roof of the roadway of the retained entry is arch-shaped, which can improve safety and ensure safety of the coal mining working face. In addition, a cutting angle is 15-20 degrees, which can effectively determine a roof caving direction after top-cutting and reduce affect to the retained entry.

Abstract: A longwall 110 mining method, wherein a haulage dip, an air-return dip and a track dip are provided, a plurality of working faces are arranged in a whole panel, both an upper gateroad and a lower gateroad of each mining face in mining are connected to the haulage dip, and the lower gateroad that retains an entry after the working face is mined is used as an upper gateroad of a next working face, and the lower gateroad of the next working face is connected to the air-return dip. The upper gateroad and the lower gateroad of each working face in mining of the present disclosure are connected to the haulage dip, and the lower gateroad of the working face is connected to the air-return dip.

Abstract: A longwall N00 mining method includes performing a no-entry excavation and non-pillar mining in N working faces of a new district, and the whole district is provided with an air-return dip, a haulage dip and a track dip, wherein the air-return dip and the track dip are located on one end of the district, and the haulage dip is connected to the other end of the district, and connected to the air-return dip. This method can not only ensure ventilation of the whole coal cutting are, but also when mining is performed in each working face in the district, entries can be automatically formed due to top-cutting pressure release by using a part of a gob area, and thereby it is not required to separately excavate any gateroad entry during mining coal nor need to retain any coal pillar, so as to save resources and improve efficiency.

Abstract: An equipment system for a self-retaining mining method mainly comprises a transition support, an end support, a following support, and a fast-retracting support. Working face gateroads do not need to advance in mining, and a coal mining machine may be used to cut a neat coal wall at the end of a district. The entry rib is automatically formed after roof caving, thus forming a gateroad in a re-mining process. The coal mining machine is under digital control when its end cuts the coal, automatically enabling the end to laterally cut the coal wall to form a vertical straight line, which is used as the entry rib of the gateroad. A scrapper conveyor works in coordination with an arc-shaped coal grabbing plate of the coal mining machine to clean up float coal at the end as much as possible.

Abstract: A constant-resistance and large deformation anchor cable and a constant-resistance device are provided. The constant-resistance and large deformation anchor cable comprises cables (7), an anchoring device (13), a loading plate (12) and clipping sheets (4). The upper end of cables (7) is fixed on the anchoring device (13) and the loading plate (12) by clipping sheets (4). The constant-resistance and large deformation anchor cable also comprises a constant-resistance device, and the constant-resistance device comprises a sleeve (8) and a constant-resistance body (5). The sleeve (8) is a straight tube. The constant-resistance body is conical, and the diameter of the lower end of the constant-resistance body is bigger than the diameter of the upper end of the constant-resistance body. The inner diameter of the sleeve (8) is smaller than the diameter of the lower end of the constant-resistance body.

Abstract: A dynamics performance testing system, for use in testing the dynamics performance of an anchor rod or an anchor rode, comprising a main machine and a measurement and control system. The main machine comprises a vertical machine frame (1), a clamping apparatus (3) arranged on the top of the vertical machine frame (1) and used for vertically clamping the top end of a sample (6), where the sample (6) is provided at the bottom end thereof with a tray (61), a drop-hammering apparatus (2) used for being dropped vertically from the vertical machine frame (1) at a set height to impact the tray (61), a lifting apparatus used for lifting the drop-hammering apparatus at the bottom of the vertical machine frame (1) to the set height, and a protection apparatus used for physical protection and isolation to reduce bodily injury and noise. The measurement and control system controls the drop-hammering apparatus to select a parameter for drop-hammering and a process of lifting and dropping.

Abstract: A tension meter of an anchor rod with constant resistance and large deformation comprises a pull rod and a hollow jack. The meter further includes: a rotation device for controlling the rotation angle of the hollow jack; a lifter for adjusting the height of the hollow jack and the rotation device; a first hydraulic pump for driving the hollow jack, wherein the hollow jack is fixed on the rotation device mounted on the lifter. The meter has a large measurement range and a high load capacity.

Abstract: A simulated impact-type rock burst experiment apparatus includes a bracket, a specimen box assembly, an X-direction, Y-direction and Z-direction loading mechanisms mounted on the bracket, and control systems. Each loading mechanism includes four supporting posts in a rectangular arrangement, a first and second frames aligned with each other and fixedly connected to both ends of the four supporting posts, a loading hydraulic cylinder and a lead screw mounted on the two frames respectively.

Abstract: A large deformation tensile testing system, for use in testing a large deformation tensile of an anchor rod or an anchor rode, comprising a main machine frame (1), a rear collet component (2) arranged at a first position on the longitudinal direction of the main machine frame (1), a front collet component (3) movably arranged at a second position on the longitudinal direction of the main machine frame (1), a telescoping apparatus (4), a measurement and control apparatus, where a sensor module thereof senses the displacement and real-time tensile of the telescoping apparatus to form real-time data to be transmitted to an analysis module and a control module, the control module that controls, on the basis of a set measurement and control scheme and of an input of the sensor module, a testing process to proceed according to a set testing condition, the analysis module for analyzing the input of the sensor module to form a test result, and an output module for outputting same.

Abstract: An experimental method for simulating an impact rock-burst, comprises the following steps: making a rock sample having a through hole or a half hole; loading initial static stresses of three directions onto the rock sample; then loading dynamic load(s) by 0.5-10 minutes, to determine whether a spalling phenomenon appears on an internal surface of the hole; if appears, and the rock sample is further damaged, determining and recording a failure course, if not appears, increasing the static stress(es) or the intensity of the dynamic load, then repeating the experiment procedure as far as the rock sample goes into the failure course, then determining and recording the failure course, and ending the expierment. The impact rockburst induced by dynamic load is simulated in the rock sample successfully, and by sudying mechanical mechanisms of the rock-burst, the present application lays foundations for gradually understanding and mastering the nature of real rock burst.

Abstract: The present disclosure relates to a simulated impact-type rock burst experiment apparatus comprising a bracket, a specimen box assembly, an X-direction, Y-direction and Z-direction loading mechanisms mounted on the bracket, and control systems. Loading mechanism comprises: four supporting posts in a rectangular arrangement, a first and second frames aligned with each other and fixedly connected to both ends of the four supporting posts, a loading hydraulic cylinder and a lead screw mounted on the two frames respectively. The present disclosure is able to load static and dynamic loads to the rock sample in three directions perpendicular with each other, thereby performing experimental method for simulating an impact rockburst. Furthermore, the structures of the three sets of loading mechanisms are substantially the same, which have good symmetry, therefore, it is more easily and accurately to control the operation for loading static or dynamic load to the rock sample.

Abstract: A dynamics performance testing system, for use in testing the dynamics performance of an anchor rod or an anchor rode, comprising a main machine and a measurement and control system. The main machine comprises a vertical machine frame (1), a clamping apparatus (3) arranged on the top of the vertical machine frame (1) and used for vertically clamping the top end of a sample (6), where the sample (6) is provided at the bottom end thereof with a tray (61), a drop-hammering apparatus (2) used for being dropped vertically from the vertical machine frame (1) at a set height to impact the tray (61), a lifting apparatus used for lifting the drop-hammering apparatus at the bottom of the vertical machine frame (1) to the set height, and a protection apparatus used for physical protection and isolation to reduce bodily injury and noise. The measurement and control system controls the drop-hammering apparatus to select a parameter for drop-hammering and a process of lifting and dropping.

Abstract: An experimental method for simulating an impact rock-burst, comprises the following steps: making a rock sample having a through hole or a half hole; loading initial static stresses of three directions onto the rock sample; then loading dynamic load(s) by 0.5-10 minutes, to determine whether a spalling phenomenon appears on an internal surface of the hole; if appears, and the rock sample is further damaged, determining and recording a failure course, if not appears, increasing the static stress(es) or the intensity of the dynamic load, then repeating the experiment procedure as far as rock sample goes into the failure course, then determining and recording the failure course, and ending the expierment. The impact rockburst induced by dynamic load is simulated on the rock sample successfully, and by studying mechanical mechanisms of the rock-burst, the present application lays foundations for gradually understanding and mastering the nature of real rock burst.

Abstract: A constant-resistance large-deformation anchor rod includes a rod body (6), a tray (3), a nut (2), and a constant-resistance device (4). The constant-resistance device (4) is formed into a cylindrical structure, and the inner surface of the constant-resistance device (4) and the outer surface of the rod body (6) are both formed with thread structures. The constant-resistance device (4) is sleeved at the tail of the rod body (6), and the tray (3) and the nut (2) are sequentially sleeved at the tail of the constant-resistance device (4). The nut (2) is in threaded connection with the constant-resistance device (4). The constant-resistance large-deformation anchor rod in the invention can be automatically stretched when the tunnel surrounding rock deforms largely, and keep the constant working resistance.

Abstract: A large deformation tensile testing system, for use in testing a large deformation tensile of an anchor rod or an anchor rode, comprising a main machine frame (1), a rear collet component (2) arranged at a first position on the longitudinal direction of the main machine frame (1), a front collet component (3) movably arranged at a second position on the longitudinal direction of the main machine frame (1), a telescoping apparatus (4), a measurement and control apparatus, where a sensor module thereof senses the displacement and real-time tensile of the telescoping apparatus to form real-time data to be transmitted to an analysis module and a control module, the control module that controls, on the basis of a set measurement and control scheme and of an input of the sensor module, a testing process to proceed according to a set testing condition, the analysis module for analyzing the input of the sensor module to form a test result, and an output module for outputting same.