Under the background of new stage, new concept and new pattern, the high-quality development of mining area plays an important role in ensuring the safe supply of energy and promoting the transformation and upgrading of coal. Based on the existing research results of high-quality development of the coal industry, the connotation and characteristics of high-quality development of the mining area are proposed through summary and analysis, and the concept of high-quality development of the 16 word mining area is proposed, which is innovative, open, intensive, efficient, intelligent, safe, green and harmonious; This paper puts forward the general idea of the high-quality development planning of the Taigemiao mining area in Xinjie, and expounds the specific implementation path of the high-quality development planning of the Taigemiao mining area, which mainly includes the mining area development layout, intelligent security, green low-carbon, humanistic harmony, public services, transportation and logistics, innovation driven, management mode, etc．

Abstract: Based on the engineering research background of short-wall cemented filling in F7401E working face of Coal Mine, this paper systematically studies the key technologies of filling system, roadway mining width, filling support and filling technology by means of theoretical analysis and field measurement. The research shows that the planning and implementation of ground pulping station and two filling routes are effective. It ensures the source of filling materials; when the design width of supporting roadway is 4.5m and the design width of pillar roadway is 5m, the stress concentration can be effectively avoided; on-site efficient excavation is carried out by supporting equipment such as "intelligent comprehensive excavator + explosion-proof forklift + 40T slider", with the help of "self-propelled high-efficiency jet machine" and fully automatic hydraulic slurry retaining wall. The goal of "three-day digging a branch lane and filling a branch lane" has been achieved by blocking the upper and lower seals separately. The monthly single advance reaches 570m, and no obvious deformation has been observed by surface displacement and roof separator. The research results can be used as "three-under-top" resources, especially in irregular fault tectonic areas. The efficient and economic recovery of block resources has high application value.

Aiming at the problem of asymmetric large deformation of surrounding rock caused by unreasonable coal pillar width in gob-side entry driving in inclined coal seam, 1509 return airway of a mine in Guizhou was taken as an example to study the reasonable coal pillar width of this kind of roadway. Based on the limit equilibrium theory, the calculation model of reasonable coal pillar width of coal-rock gob-side entry driving in inclined coal seam is established. Combined with the actual production geological conditions of the mine, the reasonable theoretical width of coal pillar is 4.68~5.46 m. The distribution of plastic zone, stress and displacement evolution of surrounding rock of 1509 return airway under five different widths of coal pillars are analyzed through numerical simulation. It is concluded that when the width of coal pillar is 5m, the stability of roadway is better and the recovery rate of mine can be guaranteed. After comprehensive consideration, it is determined that 5m wide coal pillar should be retained for the subsequent excavation of 1509 return airway. In the industrial test, the results of mine observation and surrounding rock drilling detection in the stable section of the subsequent new excavation support of 1509 return air roadway show that after the roadway is excavated and protected by retaining 5m wide coal pillars, compared with the original design at the same time, the contour of the roadway is relatively complete, the deformation is obviously reduced, the inner wall of the roof and the two sides of the borehole is smooth and there is no collapse hole, and the integrity of the surrounding rock is good, which is conducive to improving the stability of the coal-rock gob-side entry driving in inclined coal seam, and further verifies the reliability of the research results.

Aiming at the problems of large design amount and complex calculation amount in traditional coal mine design, by analyzing the forward design requirements of coal mine engineering, the complex mining system in coal mine is presented in an intuitive and three-dimensional way, and the secondary development idea based on Revit platform is proposed. The secondary development of Revit is carried out to expand the application function from the platform and improve the adaptability of Revit platform in BIM system to coal mine engineering design industry. Through the example verification, the main components of the underground coal mine in Guizhou Qianxin Coal Mine are developed and designed, and the corresponding attribute parameters are given to the model components to complete the automatic statistics of the engineering quantity. Combined with other BIM software, the underground three-dimensional digital model is designed, which improves the design quality and drawing efficiency, and improves the linkage between data and images. It provides a reference for the application of BIM technology in the forward design of coal mine engineering, and looks forward to the application prospect of this technology, in order to further promote the process of digital mine construction.

Abstract：Due to the lack of Typical PV System Reactive Power Compensation Design Guide, at present the reactive power compensation capacity of PV power station in coal mining subsidence area is often estimated roughly in the?engineering application, which is easy to cause the adverse consequences of insufficient compensation or waste of design. In order to solve this problem, this paper explores an accurate calculation method for reactive power compensation capacity based on electric power flow analysis principle. This method, by means of calculating and analyzing the reactive power of each node of PV power station under the conditions of full-load and no-load of PV modules, can obtain an optimal configuration scheme of reactive power compensation capacity by integrating the power factor requirements of the grid. In order to verify the rationality of this method, this paper takes a PV power station project in a specific coal mine subsidence area as an example, applies the method introduced above for calculation and analysis of the project, and the PASAP software for a simulation calculation.

At present, many open-pit mines in China have cross-transport problems, such as Pingshuodong open-pit coal mine, Xiwan Coal mine, Hequ Coal mine and so on. In order to study the feasibility of the overpass project of steel bellow in opencast coal mine under heavy load condition, taking Pingshuo Industrial Avenue project as the background, the paper proposes to use long-span steel bellow to solve the crossing problem of open-pit transportation system. The finite element software ABAQUS is used to analyze and calculate the structural stress. And Midas GTS NX three-dimensional solid finite element analysis method was used to verify the scheme. The results show that the corrugated steel tube tunnel meets the stress requirements under heavy load conditions, and the steel bellows tunnel scheme can be technically used to solve the intersection problem between the main line of Pingshuo Industrial Road and the mining truck transportation road. The research results can be used for reference to solve the cross problem of transportation system in opencast coal mine.

Line selection is one of the most important tasks in the early stage of coal highway construction, in order to evaluate the line selection from the perspective of traffic safety, this paper adopts the close-value method and selects plane and vertical indicators related to traffic safety, so as to build a complete evaluation index system. The evaluation index system is applied to the project example, and K line and B line of a certain road section of coal highway are compared from the perspective of traffic safety. The evaluation results of the close-value method show that K line is better than B line, that is, the safety of K line is better, and the line selection result of the close-value method is consistent with the actual engineering line selection, which indicates that the evaluation system constructed in this paper is effective, and it is feasible to use the close-value method to evaluate line selection of coal highway.

According to the serious deformation problem of soft bottom gob-side entry retaining in the fully mechanized caving face, taking the S1303 auxiliary air intake trough in Gucheng Coal Mine as the research object, and using the methods of on-site investigation, numerical simulation and field test, the paper analyzes the soft bottom edge of the fully mechanized caving face. The abnormal deformation characteristics of gob-side entry retention are studied, and the stress change law of soft-bottom gob-side entry retention in long-mechanized caving face is simulated and studied. The simulation results show that there is a stress peak at about 7.5m away from the solid coal, so as to determine the relevant parameters of the segmented hole reaming technology; And put forward the coordinated control technology of surrounding rock zone with the core idea of "controlling the top - limiting the help - letting the bottom" as the core idea; through the industrial test results, it is believed that this technology has a better supporting effect, improves the overall stability of the gob-side entry retaining, and can achieve efficient treatment of weak coal seam floors. Gob-side entry retaining with soft bottom under similar conditions has certain reference significance.

In order to solve the problem of serious damage and difficult control of surrounding rock of gob-side entry retaining filled with narrow high-water material, the strength characteristics of high-water material with water cement ratio of 1.6:1 were tested based on laboratory experiments, according to the engineering background of gob-side entry retaining filled with narrow high-water material in Dengmaotong Coal Mine 2202 face. Based on numerical simulation and field engineering test, the distribution law of deviatoric stress and instability failure mechanism of surrounding rock of gob-side entry retaining filled with narrow high-water material are studied. The results show that: ① with the increasing of the leading face distance, the position of the deviatoric stress peak zone gradually deflects, the magnitude of the deviatoric stress peak gradually decreases, and the closer to the working face, the more severe the mining impact; ② The deviatoric stress peak zone of the surrounding rock of the roadway within 40 m of the leading working face is mainly concentrated in the right upper shoulder angle and the left lower shoulder angle of the roadway. When the distance leading working face is more than 50 m, the deviatoric stress peak zone of the surrounding rock is mainly concentrated in the deep part of the surrounding rock of the roof and floor of the roadway, and is approximately symmetrically distributed; ③ After the mining of the working face and the completion of the gob-side entry retaining, the peak value of the deviator stress of the surrounding rock of the roadway is mainly concentrated at the solid coal wall and the roof at the solid coal wall. During the support, it is necessary to ensure that the anchor cable passes through the position of the peak zone of the deviator stress of the surrounding rock of the solid coal wall and the roof. Based on this, a sub-regional asymmetric combined control technology of gob-side entry retaining with narrow high-water material and dual-roadways is proposed, which is named roof full anchor cable support + three-row single columns in the roadway + solid coal side reinforcement with anchor cable + pre-tightened anchor bolts supplemented with single column wall in roadside high-water material + supported roof by single pillar at the side of goaf and reinforced by anchor bolt. Field engineering practice proves that the control effects of roadway sur-rounding rock is well, and the stability of gob-side entry retaining with narrow high-water material and du-al-roadways is guaranteed.

Taking mining area 2502 in the Yanbei coal mine which was affected by strong geological tectonic stress as an engineering background, the water jet technology is studied through in-site survey, laboratory test, theoretical analysis and field industrial test. The research results are as follows: the burst tendency of No.5 coal seam can be reduced to a certain extent after softening with water. The typical characteristics of rock-burst accidents mainly cause heaving floor and serious deformation of two sides. The occurrence mechanism of rock burst in roadway ribs has two different forms, and they are static load dominant type and dynamic load dominant type. The abutment stress concentration value is higher than a certain concentration static load, it will affect the coal and rock medium in the floor, and the coal and rock medium in the floor occur rock burst. The water jet technology for roadway ribs can effectively prevent rock burst of roadway ribs and floor based on the dynamic and static loads superposition theory and Terzaghi theory. The monitoring result of signal intensity by EMR indicates that the decreasing amplitude of signal intensity of EMR is about 60.2% on the side of coal-pillar rib, and the decreasing amplitude of signal intensity of EMR is about 68.6% on the side of solid-coal rib; the convergences monitoring result indicates that the convergence ratio of roadway height is about 3.2% and the convergence ratio of roadway width is about 2.3% in the pressure relief roadway part; the water jet technology is not only helpful to the prevention of rock burst for the roadway ribs, but also can play a good prevention of rock burst for roadway floor. The research results provide a theoretical foundation and a new guidance for preventing rock burst in roadway ribs and floor with similar engineering geological conditions.

Abstract：The complex exploration environment of coal seismic exploration and the influence of surrounding interference factors lead to the limitation of the use of seismic sources, which restricts the accuracy of data acquisition in coal exploration . Taking typical explosive source, vibroseis source and electric spark source as examples, this paper analyzes the source excitation and applicable conditions, carries out the test of excitation well depth and vibration superposition times, optimizes the source parameters, and compares and analyzes the test results through application examples. The results show that explosive source have less response to shallow formation information and higher sensitivity to deep formation;Vibroseis source has better exploration effect for both shallow and deep strata, with good comprehensive effect, but sometimes it is affected by the scattering of shallow low velocity layer; Electric spark source has less response to shallow formation information and higher sensitivity to deeper formation. However, limited by its excitation energy, the effect of deep formation exploration is relatively poor.

Based on the first super-long intelligent mining face with an annual output of 10 million tons of 450 m in China, the strata behavior and surface movement and deformation law are comprehensively analyzed by means of actual measurement. The results show that the average first weighting step of 450 m super-long working face is 77.1 m, and the periodic weighting step is mainly distributed in 5 ~ 15 m, with an average of 11.4 m. The periodic weighting step of super long working face is small, the weighting is frequent, the duration is short, and the weighting along the inclination of the working face is not synchronous; During the weighting period, the working resistance of the support forms two high resistance areas on both sides of the middle of the working face, showing a "saddle" shaped bimodal distribution along the inclination of the working face. The working resistance of support in 450m longwall face is mainly distributed in the medium resistance range of 8000 ~ 14000kN, showing normal distribution characteristics and good adaptability of support. Under the influence of strong mining in the super long working face, the surface subsidence has the characteristics of large influence range and fast subsidence speed, and the surface movement range and subsidence amplitude at the goaf side of the working face are significantly greater than those at the solid coal side, so the surface presents an asymmetric subsidence phenomenon. The research results can provide reference for roof management and mining design of similar super long working faces in China.

Abstract: In order to study the influence law of ground stress distribution characteristics on coal and gas protrusion, the method of combining theoretical analysis and field example verification is adopted. That is, through the numerical simulation method, we analyze the influence of the distribution of raw rock stress on the elements of mining stress field and physical and mechanical properties of coal and rock body, and explore the law of influence of stress direction on the protrusion risk of mining surface retraction. The research results show that when the maximum stress direction is perpendicular to the direction of roadway digging or surface recovery, the stress concentration phenomenon is more obvious in front of the working face, the larger the scope of the unloading damage zone, the lower the porosity of the coal body, and the stronger the risk of protrusion at the working face. And combined with the coal and gas protrusion phenomenon in the south one mining area of mulberry pine coal mine and the actual measured data of ground stress, it verifies the phenomenon that the protrusion risk is greater when the maximum main stress direction is perpendicular to the direction of advancement.

As one of the main coal bases in China, Shendong mining area provides an important support for the development of coal energy in China. Many major technological breakthroughs in the coal industry come from Shendong Coal Group, including the 8.8m mining height coal seam of Shangwan Coal Mine. However, the 8.8m mining height working face will inevitably cause the violent movement of overlying strata, lead to the development of overlying fissures, provide flow channels for the surface and aquifer water, and become the potential danger of mine safety production. Based on the engineering practice of working face No.12402 with large mining height in Shangwan Coal Mine, and on the basis of analyzing the hydrogeological conditions of the working face, this paper selects the key control area of water prevention and control, establishes the numerical model of the working face with large mining height by using the discrete element software, and studies the development law of the height of the water conducting fracture zone in the overlying strata during the mining process of the working face with large mining height. The results show that the height of the water conducting fracture zone is 95.02~112.00 m, which can connect to the surface, and the surface subsidence deformation reaches 7.19 m. In the season of heavy rainfall, it must have an impact on the water prevention and control work; along the working face, the water diversion fracture of the overlying strata tends to be "saddle shaped" distribution. Due to the compaction of the central area of the goaf, the overlying area corresponding to the trough of the super high working face becomes the key point of the water prevention and control work. Based on the above research results, the surface water and loose aquifer water prevention and control measures are formulated from the aspects of water source distribution and underground drainage facilities. The surface water is discharged in advance and the collapse pit is backfilled, the bedrock aquifer is discharged underground, and the standby drainage facilities are arranged within 200m of the return air way, which provides a strong guarantee for the safe mining of the working face.

Water disasters and broken surrounding rock are the main hydrology and engineering geological problems faced by deep roadway excavation under high water pressure and high in-situ stress.Taking the 87 mining area of Zouzhuang Coal Mine in Huaibei as the research object, directional multi-branch borehole along roadway exploration and subsection high pressure grouting technology are proposed to treat roadway group passing through aquifer and fault fracture zone.The spatial location and morphology of the Taiyuan Formation limestone and fault fracture zone are identified.A water-repellent zone is formed around the roadway through segmented high-pressure grouting, and the effective treatment range of the aquifer is greater than 30m. After treatment, the water yield of the verified drilling hole is reduced by about 50%, and the maximum water inflow of a single hole is less than 2m3/h. High pressure split grouting consolidated the fault-broken rock mass, the shotcrete and bolt support was used to pass through the fault zone, without slicing and roof falling. Directional multi-branch hole grouting technology is an effective means to solve the problems of broken surrounding rock and water damage faced by deep buried roadway excavation. The concept of disaster control has been transformed from underground treatment to surface treatment, from treatment while digging to treatment before digging, and from section to region. It has a wide application prospect in the field of advanced treatment of roadway penetrating large fracture or high confined aquifer

Aiming at the occurrence of hard and thick strata in the overlying strata, a similar model of the hard and thick strata overlying the working face was made by using the method of similar material simulation test, and the structure of the overlying strata and the evolution characteristics of fissures under the hard and thick strata and the analysis of the causation of disasters were studied. The research results show that after the advancing of the working face, the overlying rock layer gradually forms a trapezoidal structure, and the existence of the hard and thick rock layer shields the longitudinal development of the trapezoidal structure; Most of the space created by the gas accumulation creates space for gas accumulation; the fractured fractures and the abscission fractures are connected to each other, forming two-way intercommunication vertical fractured fracture areas on the working face side and the incision side, providing a path for gas migration. The gas released near the mining coal seam enters the maximum abscission crack in the overlying rock along the vertical fracture areas on both sides, and finally accumulates in the maximum separation crack under the hard and thick rock layer that occupies most of the space for coal seam mining.After the hard thick rock stratum is broken, the gas space decreases sharply, the gas pressure rises rapidly, and the gas flows to the working face through the vertical fracture fissure area on both sides, which is easy to induce gas outburst and other disasters.

In order to deeply analyze the characteristics of crack development and strain evolution of coal samples under uniaxial compression, digital speckle technology was used to obtain the full-process images and data of the crack field and strain field of the specimen during the test. The global cracks development and strain evolution process of the specimen are analyzed, and the internal relationship between strain evolution and crack development is obtained. Based on this, the key cracks of the specimen are selected, the development of local cracks is further analyzed, and the evolution characteristics of the local horizontal strain, vertical strain, maximum principal strain field and the direction of the maximum principal strain with the acquisition frame are clarified. The results show that: the strain evolution of the specimen is potentially related to the development of cracks. There is often obvious strain concentration in the development of cracks, and there will be concentrated distribution of horizontal strain and vertical strain at the inclined or curved cracks. And the horizontal strain concentration is relatively large. In a curved crack, When the degree of opening is large, it is affected by the vertical compressive stress, which tends to produce large vertical deformation, and induce horizontal deformation in the opposite direction. There will be phenomena such as crack closure, sharp increase in vertical strain, and sharp decrease in horizontal strain. When the crack opens or expands, the maximum principal strain increases, and at the same time, there will be obvious strain concentration; When the crack is closed, the maximum principal strain decreases and the strain concentration also decreases; The direction of maximum principal strain is basically the same as the crack opening direction, and is basically perpendicular to the crack propagation direction. In addition, when the acquisition frame reaches 89% of the failure frame of specimen, the specimen's cracks develop rapidly, and thereafter, it also shows rapid concentration of local strains. And when the specimen cracks are generated or destroyed instantaneously, the maximum principal strain direction will also change greatly. The test results can be used as one of the precursors of the specimen failure early warning.

TIn order to explore the nature of the advance influence of the surface movement, mechanism of the key layer rupture on the advance influence of the surface movement was revealed. Based on the theory of key strata, this paper analyzes the influence mechanism of surface movement and deformation in advance. By analyzing the internal displacement monitoring records of boreholes in Shendong mining area, the results of physical similarity simulation tests, the occurrence law of rock pressure in fully mechanized mining face, and the observation records of surface subsidence, the relationship between the key strata break and the periodic variation of the influence distance (angle) are studied. The results show that the advance influence distance (angle) is not a constant, but a variable that changes periodically. A new viewpoint that the difference between the maximum value and the minimum value of the advance influence distance is roughly equal to the periodic weighting length of the working face is put forward originally. Examples show that the new viewpoint is scientific and reasonable. The paper provides a new technical idea for the organic unity of mining pressure and surface deformation.

In order to explore new technologies for the prevention and control of abnormal gas emission disasters in coal mines, develop intelligent early warning and prevention and control equipment for gas disasters, and ensure the safe and efficient mining of high gas mines, based on the complex characteristics of abnormal gas emission disasters in coal mines. The research results and practical experience are obtained from the four aspects of gas geological anomaly area detection technology, ventilation dilution abnormal gas technology, drainage technology in abnormal gas area and emergency treatment of abnormal gas emission, and from the aspects of dynamic transparent gas geology, multi-source information intelligent detection technology, big data mining technology of abnormal gas emission, intelligent prevention and control technology of abnormal gas emission, robot emergency rescue technology for abnormal gas emission accident, five aspects are prospected, which points out the direction for improving the disaster prevention and control ability of abnormal gas emission in coal mine and reducing the occurrence of mine safety accidents.

Abstract:In view of the coupling law of erosion overburden fracture evolution and gas migration and emission after mining in the working face of composite key strata, taking 12313 fully mechanized caving face in Wangjialing Coal Mine as the engineering background, through studying the erosion overburden activity and fracture evolution after working face advancing, the distribution characteristics of erosion overburden fracture in the working face are obtained, and the numerical model is established to analyze the pressure relief gas migration law. Finally, the research results are applied to the field gas control and effect test of 12313 fully mechanized caving face.The results show that the initial breaking distance of composite key strata in 12313 fully mechanized caving face is 49.84m.The height of the “two zones” composed of the caving zone and the fracture zone of the strike model is 121.1m. The widths of the fracture zone on the side of the cut and the working face are 45.6m and 44.6m, respectively. The caving angles of the cut and the working face are 62° and 60°, respectively.The height of the“two zones” of the caving zone and the fracture zone of the dip model is 115m. The width of the fracture zone on the side of the tape channel and the side of the return air channel is 37m and 40m, respectively. The caving angles of the tape channel and the return air channel are 62° and 63°, respectively.The maximum gas concentration in the upper corner of 12313 fully mechanized caving face can be maintained in a safe range after applying high directional drilling and buried pipe drainage measures.When the buried pipe depth is 17.3 m, the gas concentration in the upper corner reaches 0.478 %, which effectively solves the problem of gas overrun and accumulation in the upper corner, and can provide reference for gas control in coal mining face under similar conditions.

Using #425 Portland cement, fly ash and UEA expansive agent to develop fly ash based UEA modified grouting material, the shrinkage measurement and uniaxial compressive strength mechanical experiment of 15 grouts with different ratios during curing period were carried out in the laboratory by rigid testing machine to study the natural deformation, mechanical properties and instability mode of fly ash based UEA modified grouting material. The uniaxial compression test is carried out, the influence of UEA content on the shrinkage, failure strength, peak strain and instability mode of grouts is analyzed, and the instability mode and critical value point of fly ash based UEA modified grouts are determined. The results showed that with the increase of UEA content gradient (0 ‰, 2 ‰, 4 ‰, 6 ‰, 8 ‰), the initial shrinkage of stone body decreased by 41.55%, 2.63%, 1.77% and 2.22% respectively, and the later shrinkage of grouts decreased by 45.61% and 61.29% respectively (C0, C1 and C2); With the change of UEA content gradient, the failure strength of the sample increased by 49.15%, increased by 3.96%, decreased by 18.18% and increased by 4.95% respectively; With the change of UEA content gradient, the peak strain of stone body increased by 1.66%, 1.41%, 4.37% and 1.70% respectively. UEA expansive agent significantly increased the peak strain of grouts, showing a linear increasing trend; The failure and instability modes of fly ash based UEA modified grouts are low-strength large deformation complex failure and high-strength small deformation failure. The critical point of the two instability modes is that the failure strength of slurry stone body is 1.5MPa.

Taking the mudstone obtained from Kouzidong coal mine, Fuyang, Anhui, as the research object, nanoindentation test was carried out on this mudstone. Based on the elastic theory and energy principle, the meso-mechanical properties and fracture characteristic were investigated. Furthermore, difference in meso-mechanical properties of main composition of mudstone was analyzed. Results showed that under the same maximum load, the indentation depth on the mudstone surface varied different. The elastic modulus was in the range of 2-114 GPa, and the hardness ranged from 0 GPa to 16 GPa, reflecting the heterogeneity of the mudstone. Based on the probability density distribution of modulus, three different main phases were identified, including clay minerals (~ 7.83 GPa, including kaolinite and illite), chlorite (~ 41.67 GPa) and quartz (~ 97.29 GPa). Morever, the fracture toughness of clay minerals, chlorite and quartz was 0.09, 0.91 and 1.95 MPa·m1/2, respectively. The fracture toughness of clay minerals accounted for the largest proportion (~ 70.0 %), and the clay minerals played a significant effect in macro-fracture properties. By the obtained mesoscopic mechanical properties and fracture toughness of different phases of mudstone, it was useful to understand the macroscopic failure behaviour of mudstone.

Taking a mine in Shendong mining area as the research object, the water content, pH, alkali hydrolyzable nitrogen, available phosphorus, available potassium and organic matter of 10cm, 20cm and 30cm topsoil were selected as the evaluation indexes of soil environmental quality, and their temporal and spatial variation rules were analyzed. The results show that the water content in the undrawn area at each depth is higher than that in the subsidence area. The soil water content in the 1-year subsidence area at the depth of 10cm is slightly higher than that in the 2-year subsidence area, while the water content in the depth of 20cm and 30cm is lower than that in the 2-year subsidence area, indicating that the water content in the 2-year subsidence area has recovered compared with that in the 1-year subsidence area; The range of pH change in the area is small, and the soil is alkaline as a whole. In terms of spatial distribution, the area with small pH is mainly distributed at the junction of the 2-year subsidence area and the other two areas, which is consistent with the direction of coal mining roadway; The spatial distribution of alkali hydrolyzable nitrogen, available phosphorus, available potassium and organic matter is consistent. The low value areas are mainly concentrated in the middle of the untapped area and the northwest, middle and south of the one-year subsidence area, and the high value areas are mainly concentrated in the junction of the two-year subsidence area and the one-year subsidence area and the untapped area, but the coverage area is slightly different. In general, coal mining disturbance has a certain fluctuating impact on soil ecological quality, but the impact is light.

In the intelligent process of hydraulic support electro-hydraulic control system based on CAN bus, there is a large amount of communication data, bus data conflicts increase, and high-priority nodes occupy the control of the bus, resulting in the hunger phenomenon of continuous failure of low-priority nodes, which seriously affects the real-time communication and hinders its intelligent process. Aiming at this phenomenon, this paper analyzes the hydraulic support electro-hydraulic control communication system in detail, designs CAN identifier and dynamic scheduling algorithm based on the system structure and information characteristics, and proposes a bus dynamic scheduling strategy based on EDF(Earliest Deadline First). The dynamic scheduling strategy can greatly improve the node hunger phenomenon, reduce the average delay of the system, improve the real-time performance of the system, and lay a good foundation for the realization of automatic unattended working face.

Gyratory crusher is the key coarse crushing equipment in the material crushing link, the bulk of the broken material is large, the motion state of the material in the crushing chamber is complex and changeable, especially the key working parameters have a great impact on energy consumption, domestic related enterprises lack the theoretical model of crushing energy consumption to guide the reduction of energy consumption in the design and manufacturing process. Based on the basic parameters of Metso 60-110E gyro crusher in Finland, this paper uses Solidworks to build a three-dimensional model. Based on the discrete element simulation software EDEM, it analyzes the influence of key parameters such as precession Angle, bottom Angle of moving cone, speed of moving cone, and size of ore outlet on energy consumption of the crusher, and establishes a theoretical prediction model of energy consumption of the crusher. The key parameters of the gyratory crusher are obtained. The results of response surface analysis and model variance analysis show that the precession Angle and cone speed have the most significant influence on the energy consumption model. When the same crushing force is obtained, the precession Angle is 0.48°, the bottom Angle of the moving cone is 79.99°, the rotating speed of the moving cone is 130.00 r /min, and the size of the ore outlet is 166.24mm, the performance of the gyratory crusher is optimal. Compared with the unit energy consumption of the gyratory crusher under the original working parameters, the energy consumption is reduced by about 1.9%. Finally, by comparing with the field data, the model is basically reliable. The model can provide reference for the design and energy consumption prediction of high performance gyratory crusher.

As an important part of the coal industry, transportation system undertakes the historical mission of green reform in the coal industry. By analyzing the transportation status and transportation structure of the coal industry, this paper summarizes the shortcomings of the traditional transportation mode in safety, environmental protection and intensification, as well as the problems of low structural stability and limited development space in the transportation system. On this basis, this paper introduces the basic principle, development process and application status of pipeline transportation technology in relevant fields at home and abroad, and discusses the technical advantages of slurry pipeline transportation technology in coal industry, including green environmental protection, safety, reliability, intelligence and efficiency. The analysis and research shows that slurry pipeline transportation technology has obvious technical advantages in coal resource transportation and coal based solid waste transportation, has broad market development prospects, and is conducive to the adjustment and optimization of transportation structure of coal industry. However, there are technical challenges such as high degree of technical integration and difficult management and coordination, which need to be solved urgently. It is pointed out that (1) smart pipeline transportation; (2) Pipeline transportation of slurry with wide particle size and high concentration; (3) The construction of green pipeline transportation system in energy-based cities is the future development direction of slurry pipeline transportation technology in the coal industry. The research results provide a new idea for the selection of transportation mode in the coal industry, and lay a foundation for optimizing the industry transportation structure, improving the system stability and realizing green transportation.

Abstract: As an important component of the underground heat exchange system, the performance of the coaxial heat exchanger in medium-deep geothermal wells directly determines the efficiency of geothermal energy development and heat extraction effect. In this paper, the relationship between the heat-insulating inner tube and the heat transfer performance of coaxial heat exchanger in medium-deep geothermal wells is investigated through field tests and numerical simulations, and the effects of the length of the inner tube insulation and the insulation scheme on the water temperature and heat extraction power of the coaxial heat exchanger are analyzed. The results show that the short-term heat extraction power of the coaxial heat exchanger is 1506.83 kW when a real aerogel insulated tube with a thermal conductivity of 0.06 W/(m·K) is used as the inner tube, and for a geothermal well of 3500 m depth, the thermal insulation performance of the inner tube decreases with increasing depth, and the thermal insulation performance of the 0～1400 m section has a greater influence on the overall heat transfer effect. Increasing the flow rate in the tube can reduce the effective insulation length of the inner tube. The results of the study can be used as a reference for the efficient development and utilization of medium and deep geothermal energy and the optimal design of coaxial heat exchangers.

In view of the serious wear problem of the middle groove side of scraper conveyor at present, the DEM-MBD coupling model of scraper conveyor was used to simulate its transportation process. It is found that in the process of scraper conveyor from no load to full load, the concentrated area of pressure inside the groove side gradually transfers from the lower edge of the groove side to the upper edge of it. And at stable full load, the pressure range of the upper edge of the groove side is 9842~10890 Pa, significantly greater than the maximum pressure of the lower edge of 8742 Pa, which is consistent with the severe wear of the upper edge of the groove side; The force exerted by the scraper on the groove is concentrated on the upper edge of the groove side, and the force ranges from 23950 N to 160350 N, with an average value of 85509 N, which is 30.76 times of the mean force exerted by coal on the groove side, indicating that the wear of the upper edge of the groove side is mainly caused by the rigidly rigid body wear between the scraper and the groove. The curve of the inner side of the groove was optimized, and the results showed that the pressure on the inner side of the groove and the force of the scraper on the groove side were reduced by 19.34% and 42.51% respectively, which provides a basis for the optimization of the groove structure.

Water inrush is one of the major disasters in coal mine. Aiming at the problems of low efficiency and difficult installation and transportation of emergency drainage equipment in coal mine water inrush rescue at present, a variable wheelbase coal mine water inrush emergency drainage vehicle was designed. and its dynamics was analyzed by RecurDyn software. The virtual prototype model of the emergency drainage vehicle was established in the RecurDyn software, and the simulation of the upward movement and the downward movement of the emergency drainage vehicle with different wheelbase sizes and the maximum slope of 30° was studied by using multi-body dynamics simulation. Influence of Coaxial Distance on Torque of Track Drive Wheel. The research shows that when the wheelbase is larger than 1470mm, there is a difference of 2078N m in the torque of the left and right crawler driving wheels big slope. Therefore, when crawling on a steep road, the load can be biased to reduce the torque difference between the left and right tracks and improve the climbing performance. Through the dynamic analysis of the virtual prototype, a scientific basis is provided for the functional realization and stable operation of the real vehicle.

Material management is an important part of construction project management, this paper discusses the material control of the general contract project from the view of the general contractor, and discusses the material control system procedures and implementation contents, this paper sets up the material control management system of the general contract project and identifies the core work and key content of the material control, and realizes the whole process management of materials in general contract project, so as to provide reference for material management of general contract project.