In order to improve the single lane two-way traffic capacity of gentle slope inclined shaft and minimize the capital construction quantities of passing chambers, so as to maximize economic and technical benefits, it is necessary to reasonably solve the layout of passing chambers, especially the setting spacing of chambers. Based on the research results of previous technicians, this paper puts forward two formula models to calculate the setting spacing of the meeting chamber, and studies the section parameters of the meeting chamber. In view of the differences between the two formulas in calculation process and results, the two formulas are analyzed and compared from the aspects of calculation ideas, complexity and engineering practical application. It is considered that although the second formula model has the disadvantages of complex calculation process and high requirements for operation and management, it realizes the utilization of gentle slope inclined shaft to a greater extent, Reduce the capital construction quantities of meeting chamber. The design idea or license proposed in this paper provides reference for coal mine design and construction.

Aiming at the problem of safe upward mining after the 5-2 coal room mining in Shenguang Coal Mine, the feasibility of upward mining of 4-2up and 4-3 coal seam and the stability of coal pillars are demonstrated by theoretical analysis. A three-dimensional numerical model was established by using 3DEC. The influence of room mining of 5-2 coal seams on the integrity and continuity of 4-2up and 4-3 coal seams was studied. The influence of upward mining of 4-2up and 4-3 coal seam on the stability of interlayer strata and coal pillar was analyzed. The results show that the ratio K of 4-2up and 4-3 coal seam is 33.07 and 23.46 respectively, which are higher than the critical value 7.5, and the ultimate bearing strength of coal pillars in the goaf of 5-2 coal seam is 7.84MPa. 4-2up and 4-3 coal seams still have certain integrity and continuity after 5-2 coal mining. The upward mining of 4-2up and 4-3 coal seam reduces the stress and displacement of interlayer rock and does not have a destructive effect on the interlayer strata and the coal pillar left in the mined-out area of 5-2 coal seam. The mine pressure behavior of interlayer strata is not obvious. Theoretical analysis and numerical simulation results show that the 4-2up and 4-3 coal seam in Shenguang Coal Mine meet the upward mining conditions.

According to the actual production situation of Changcheng Minmetals in Inner Mongolia, aiming at the problem of coal mining under buildings, water bodies and railways, a set of continuous mining and continuous filling gravity filling process is designed, which is divided into two parts: "pulping" and " Gangue transportation ". The pulping station is controlled by computer for full-automatic production, and the running state of the system is monitored from time to time through computer image visualization technology. Secondly, the design, assembly, commissioning and run of the gravity filling process system are completed.Finally, the filling effect is analyzed, which proves that the continuous mining and continuous filling gravity flow filling technology is completely feasible in the filling mining of Changcheng Minmetals, realizes green mining, and can effectively solve the problem of coal mining under buildings, water bodies and railways of Great Wall Minmetals.

Aiming at the problems that the current mine intrinsically safe power supply has slow protection response speed and low output power, which cannot meet the needs of underground electricity and restrict underground integration and intelligent production, an intrinsically safe short-circuit protection based on the rate of change of fault current is designed. Circuit. In this paper, the intrinsically safe power supply is equivalent to a potential capacitance circuit and the short-circuit fault characteristics are analyzed. It is found that the fault current rises rapidly and abruptly occurs after a short-circuit; an intrinsically safe short-circuit protection circuit based on the rate of change of the fault current is designed, which can quickly and accurately detect the intrinsically safe power supply Short-circuit fault; Intrinsic safety performance test results show that: after a short-circuit fault, the transient output energy is 80.667μJ, self-recovery and soft-start performance are stable, and meet the design requirements.

In view of the complex wiring, high cost, and poor flexibility of the wired monitoring system for coal mine equipment status, in order to improve the limited communication distance, poor anti-interference ability, and high energy consumption of the existing wireless monitoring system, and solve the problem of the existing monitoring system data. To access the shared information island problem, a wireless sensor acquisition system for mines based on MEMS technology is studied. The overall design plan of the system, the hardware circuit design and software implementation of the collector and concentrator (including the compilation of communication messages) are introduced in detail, and the reliability of the system is verified by tests. The results show that the wireless sensor acquisition system can flexibly adapt to the complex working environment of coal mines and underground, realize real-time, long-distance, and wireless transmission of vibration and temperature signals of coal mine equipment, and can provide rich resources for health monitoring and fault diagnosis of mining equipment Data support.

n order to speed up the intelligent construction of open-pit coal mines, the comprehensive information management and control platform for intelligent open-pit coal mine is proposed. Based on the big data service platform, the data of various automation systems/information systems in open-pit coal mines are studied to provide cross-system and diversified data governance for the intelligent open-pit coal mine information integrated management and control platform, and the cloud service model that can be quickly deployed provides intelligence for it System application.Comprehensive information management is supported by the data, computing power and environment of the big data platform. The platform is designed around the semi-continuous process flow of the open-pit coal mine, and respectively designed the intelligent dispatch center, the intelligent three-dimensional geological center, the intelligent production control center, and the comprehensive safety monitoring and early warning and emergency command center.According to the development of intelligent technology, the specific system of the center was sorted out, and specific scientific ideas were put forward for the intelligent design of open-pit mines.

China strives to achieve carbon neutrality by 2060, and the coal industry aims to control coal, reduce carbon and improve energy efficiency. The coal preparation industry has also entered the era of stock economy. This paper introduces the development status of CPP in China in terms of coal preparation process, coal preparation equipment, structural form of buildings and structures, product loading form, automation, digitization and intelligent level, and forecasts the future development trend of coal preparation plants: first, the technical transformation of coal preparation plants in the future will increase the end coal system in power CPP,The coking CPP shall increase the three product process and the slimless transformation of the CPP; Second, BIM will be gradually promoted in the design of CPP; Third, the focus of CPP equipment should be on basic research and intelligence; Fourth, the future goal of the CPP is the unmanned black box plant.

In recent years, it is an effective way to use gas-fired internal combustion engine to burn coal mine gas driven generator for power generation, and the design of fire water system for coal mine gas power generation project has always been a difficulty in design, this paper summarizes the design of fire water system for Coal Mine Gas Power Generation Project, and probes into the pain points, difficulties and solving methods of fire water system design for this type of project, taking a coal mine gas power station project design in Jincheng, Shanxi Province as an example, it provides the reference and the reference for the fire protection designer.

Aiming at the large deformation of the roadway that still occurs with the 5210 working face under the condition of high-strength support in the 5209 return airway of Madaotou Coal Mine, theoretical analysis, numerical simulation, field experiments and other methods are used to conduct underground directional blasting for large mining heights and thicknesses. The technology of roof cut and pressure relief by directional blasting in roof roadway has been studied. The research results show that the working principle of roadway blasting and top-cutting pressure relief is to blast and top-cut the basic top rock layer on the side of the coal pillar to make it collapse in time, reduce the load of the coal pillar and the basic top rock layer due to the rotation and sinking. The load on the coal pillar; the basic top rock strata is reduced in both the initial collapse step and the periodic collapse step after the roof is cut and relieved, thereby reducing the appearance of the rock pressure; the best cutting angle for the blasting and pressure relief is at 60°, after blasting and cutting the top and releasing the pressure, the peak stress decreased from 21.1 MPa to 16.3 MPa; after the blasting, the drilling and peeping results showed that the blasting hole and the pilot hole produced a gap with the direction along the direction of the energy-concentrating tube in the hole Cracks in the same direction; observation of the surface displacement of the roadway in the 5209 return airway revealed that the overall deformation is small and the roadway integrity is good, indicating that the directional blasting has a significant effect of top-cutting and decompression.

in order to solve the technical problem of water gushing from the shaft wall after the formation of inclined shaft in Camel Mountain coal mine,A rotary jet grouting support method is proposed to cut off the water inflow to make up the water source, fill the loose circle behind the shaft wall and improve the stability of the surrounding rock of the shaft.Based on the analysis of voids and cavities behind the shaft wall caused by water gushing and sand carrying in the Quaternary System of the main inclined shaft and the weathered zone of the bedrock at the lower part of luoluoshan coal mine, the water supply source of water gushing in the main inclined shaft is cut off by rotary jet grouting method, and the voids and cavities formed by long-term water gushing and sand carrying in the shaft are filled by back wall grouting technology, so as to strengthen the shaft and further block the water gushing in the shaft.At the same time, the grouting treatment effect is verified by means of water level observation in the treatment area, flow field change analysis, borehole verification and water inflow change analysis.The results show that rotary jet grouting and back wall grouting can not only block the water inflow of the shaft, but also fill and strengthen the voids and cavities behind the shaft wall, so as to eliminate the potential safety hazards during the later production and operation of the shaft, which has a good reference value for the treatment of water inflow of inclined shaft.

Grouting curtain closure is one of the main technical methods for water prevention and control in groundwater abundant mines. The “fifth aquifer” of Zhuxianzhuang coal mine in Huaibei mining area have the characteristics of large static reserves, good runoff conditions, high water pressure and strong dynamic replenishment, which seriously threaten the mining of the No.8 coal seam. A water control plan of "curtain closure and draining mining" was proposed. Aimed at the karst fissure aquifer with large buried depth, huge thick layer, and extremely strong water-rich, the ground bedding borehole grouting technology was applied to the curtain closure project for the first time. Developed drilling double-row parallel dislocation hole layout, internal and external cross inspection method. The grouting control technology of pressure control and multi-time control grouting, and a three-stage quality inspection system have proposed. Finally, the curtain construction technology of deeply buried huge thick and water-rich aquifer based on ground bedding borehole was formed. An engineering demonstration was carried out in Zhuxianzhuang Coal Mine. The curtain seepage was less than 40m3/h, the interception rate was greater than 98%, and the water level difference between inside and outside was 350m. The curtain closure effect is good, and the coal resources under the Liberation Five Containment are more than 15 million tons.

In view of the deformation and failure of the withdrawal channel of the rock burst mine, the influence on the withdrawal roadway in the mining process of the working face is analyzed, and the change of the support pressure in the double withdrawal channel is analyzed combined with the field data, Formulate targeted prevention and control measures and analyze the effect. The results show that the deformation and failure of the withdrawal roadway are affected by the mining of the working face. When the remaining length of the working face is closer to the main withdrawal channel, the greater the bearing pressure of the withdrawal channel and the more concentrated the pressure on the two sides of the roadway, the more prone the roadway to deformation and failure. Based on the characteristics of easy deformation and damage of the main withdrawal channel, the effect of roof presplitting blasting is analyzed. After presplitting blasting, the range of stress variation in the blasting area is significantly reduced, indicating that roof presplitting blasting can reduce the stress concentration of the withdrawal channel affected by the mining of the working face. At the same time, it also blocks the stress transmission path in the goaf and weakens the transmission path of advance bearing pressure in the working face.

In order to reduce the horizontal stress concentration degree of near-vertical coal seam working face, the principle of pressure relief by blasting at the top and floor of near-vertical coal seam is analyzed theoretically, and the parameters of deep and shallow hole blasting pressure relief scheme are determined. The effect of pressure relief blasting is analyzed by means of borehole imaging, electromagnetic radiation and micro seismic data analysis. The research results show that: After deep and shallow hole blasting, a three-dimensional "buffer zone" is formed in the rock layer of the roof and floor, which hinders the transmission of high level in-situ stress to the working face and reduces the degree of stress concentration. After blasting, new cracks are developed in the roof and floor, and the number increases by about 46.6%. Some cracks are expanded into bed separation and local broken zones appear. After blasting, the electromagnetic intensity of coal and rock mass on both sides of the working face decreases obviously, and the micro seismic energy and frequency show the law of first increasing and then decreasing before and after blasting, which has played a good effect of pressure relief.

Abstract:Is long mining pits for a long time under the influence of the thick sandstone roof aquifer, water fractured zone height is mine safety mining under water body is an important parameter, for his long mine sublevel caving mining under thick sandstone aquifer water flowing fractured zone height, this paper collected the mining area 17 groups of working face water fractured zone height measurement data for analysis.The results showed that;Lead water fracture zones empirical formula calculation results in his long mining area distortion problems, is not as his long mining area calculation formula for reference of the fissure zone, based on the use of the collected 17 groups of working face water fractured zone height measured data using multiple regression analysis it is concluded that the long Yu Bin mining area calculation new formula of the fractured zone height,Based on the background of ZF1403 working face in Yadian Mine, the height of water-conducting fracture zone was studied by means of regression formula, numerical simulation and field measurement. The results of the three research methods are basically consistent, and the application effect of regression formula is good.

In order to prevent the spontaneous combustion of residual coal in goaf caused by the interworking of air flow in adjacent goaf after mining of close coal seam group working face. Taking the 31114 fully mechanized mining face of lijiahao coal mine as the engineering background, the oxygen concentration distribution law on the inlet side and return side is measured by using the method of field analysis and numerical simulation. According to the oxygen concentration distribution law, the distribution range of "three zones" of spontaneous combustion in the goaf of the mining layer is delimited, and the minimum advance degree of safe mining in the working face is given. At the same time, the distribution law of oxygen concentration in the overlying goaf of coal seam group mining is simulated by FLUENT software, the key prevention and control area of fire in the goaf of the upper adjacent layer is delimited, and the comprehensive fire prevention and extinguishing measures combining ground plugging, corner plugging and grouting at the position of residual coal pillar are proposed.

For the poor dust control efficiency and wettability of the solution spray in the fully mechanized mining face, the dust control technology using surfactant-magnetized water was proposed. The strong wetting properties of the surfactant-magnetized water were measured, of which contact angle, dust deposition time and dust control efficiency have been greatly improved than that of the untreated water. Meanwhile, the preparation process of the surfactant-magnetized water was put forward. The field application results in the 12100 fully mechanized mining face, Shoushan No. 1 Mine showed that the dust removal technology using surfactant-magnetized water can effectively reduce the dust concentration in the working face. The average dust removal efficiency of respirable dust and total dust at different measuring points reaches 84.67% and 88.52%, respectively, effectively improving the working environment of underground workers.

In this paper, to further study the rock burst prevention technology under the specific geological conditions of hard-thick roof strata, the rock burst process of the overlying hard-thick roof strata in the mining process of I010203 working face of a mine was analyzed, the corresponding technical measures were put forward, and the effect of the prevention technology based on the temporal and spatial variation law of ME events before and after the pressure relief and erosion prevention of the working face was tested. The results show as follows: after the mining of B2 coal seam, the overlying hard-thick roof strata was easy to produce hanging roof in the goaf of I010203 working face and the coal pillar area between the I010201 goaf. This part of hanging roof would not only cause the static load stress concentration of coal body, but also cause energy accumulation, resulting in a lot of dynamic load. When the length of hanging roof was too long, strong dynamic load disturbance such as caving and breaking would occur, when the superposition of dynamic load and static load exceeded the critical value, rock burst would occur. The concentrated static load of coal pillar and the dynamic load of hard roof strata breaking were the main controlling factors of rock burst. According to the above analysis results of rock burst, two kinds of pressure relief technical measures (roof breaking pre splitting and advance coal blasting) were designed. The ME events during stable production period before and after pressure relief were selected for comparative analysis of pressure relief effect. It is found that after pressure relief, the daily total energy and frequency of ME events are significantly reduced, and the ME events above 103-104J are significantly reduced, and the spatial distribution of ME events is relatively scattered. The ME events near the roof are significantly reduced, which indicates that the pressure relief measures can effectively reduce the rock burst hazard. The research results can provide a reference for the formulation of pressure relief technical measures of hard-thick roof strata in coal mine.

Surface subsidence laws under the influence of fault is significantly different from that under common geological conditions. In order to study mining subsidence mechanism influenced by fault, the disturbance of working face mining on overlying rock is regarded as the transfer of stress wave in rock stratum medium. At the same time, the stress expressions of wave transferring from weak rock to hard as well as from hard rock stratum to weak are established. Stress wave transmission influenced by weak strata medium is ana-lyzed by theory and numerical calculation to reveal the mechanism of fault barrier to overburden movement and stress transfer. At last, it’s verified by similar model experiment and the influence of different fault characteristic parameters on the barrier is analyzed by numerical calculation. The study has showed that firstly, the disturbance of mining on overlying rock is closely related to the stress wave velocity generated by mining, and the greater the stress wave velocity is, the greater the disturbance of mining on overlying rock is. Secondly, fault rock mass being as fractured zone, stress wave velocity decreased significantly after through the fault zone under the action of multiple reflection effect. The ratio of maximum stress wave velocity according to mining wall and the other side is 4.68 ~ 35.61. Fault has an obvious blocking effect on the transfer of mining-induced stress wave, that is, the fault has a blocking effect on the transfer of min-ing-induced stress, and the overburden movement and deformation mainly occur in the mining wall. Lastly, for the reason that the stress wave velocity attenuation in shallow fault zone is less than that in deep fault zone, the rock mass in shallow fault zone has discontinuous deformation before the rock mass in deep fault zone. The order of transmission and barrier effect of fault characteristic parameters on overburden movement and deformation is fault zone width > fault drop > fault dip Angle > friction angle > cohesion. The results are of practical significance to the analysis of surface subsidence laws influenced by fault and the protection of surface structures at outcrops.

Aiming at high stress level at coal mine soft rock serious floor heave, and to god source anhui coal chemical co., LTD. (Zou Zhuang coal) - 800 - m level and room as the background, on the basis of elastic mechanics and plastic mechanics theory the mechanics mechanism of floor heave is analyzed, based on the principle of overall stability of surrounding rock at the same time, the drafting of the technical scheme of the inhibition of the bass drum. The field measurement data show that the technical scheme is simple and effective, which fully demonstrates the scientificity and correctness of the research results. The results can not only be used for the research on the control mechanism and technology of floor heave in electromechanical chamber of high stress soft rock, but also for the research on the control mechanism and technology of floor heave in underground water bunker and large cross-section high stress soft rock roadway.

In order to achieve precise outburst prevention in the strip area of deep coal roads, it is proposed a method named "three-dimensional precise pressure relief" prevention of outbursts in deep coal road strips, which from the three dimensions of objective risk of coal road strips, outburst prevention technology and evaluation of outburst prevention effects. That is, firstly, based on the coal roadway outburst in-situ stress and gas dual force energy model. Through the analysis of the in-situ stress factors of coal roadways, the outburst risk of gas factors and the positive geological abnormalities, the objective dangers of coal roadway is divided into general dangerous normal areas and severe dangerous abnormal areas. Then, in view of the in-situ stress factors and gas factors in different dangerous areas, it is proposed that a dual pressure relief and anti-outburst technology, which is used floor rock roadway pressure relief and drainage combined with hydraulic pressure relief to increase permeability. Finally, it is proposed to use equivalent swelling deformation and residual gas content to accurately evaluate ground stress and gas pressure relief and outburst prevention effects, thus formed a three-dimensional accurate pressure relief and outburst prevention method for coal roadways and successfully applied. The speed of coal road excavation is increased to twice the original speed. It is realized the safe and rapid excavation of coal roads.

In order to deal with the problem of large damage to surrounding rock during blasting and driving of coal mine roadway coupled with continuous charge, through theoretical analysis, a calculation formula for the damage range of rock during blasting of finite-length columnar charge is obtained. Using LS-DYNA numerical software, the damage law of surrounding rock during blasting of different cylindrical charge structures was studied. The results show that when the continuous cylindrical charge is coupled, the radius of the cavity and the surrounding rock around the blast hole have the largest damage radius, 81mm and 311mm, respectively. When the discontinuous cylindrical charge is not coupled, the cavity radius and crack length are the smallest, 41mm and 200mm, respectively. In the fissure area, the measuring point at a distance of 120mm from the blast hole wall, when using uncoupled discontinuous cylindrical charges, the damage factor is 0.194, which are 42% and 50% of coupled continuous, coupled discontinuous and uncoupled continuous charges, respectively and 53%. In summary, when blasting and driving coal mine argillaceous siltstone roadways, the use of uncoupled discontinuous columnar charges can not only make full use of the energy during blasting, but also reduce the damage to the surrounding rock of the roadway by the blasting load.

Gangue filling mining can reduce the possibility of roof collapse in goaf and play a key role in controlling surface subsidence deformation. In order to evaluate the effect of gangue filling more easily and accurately, taking Xinyuan Coal mine as the engineering background, the selection of gangue filling equipment was firstly summarized, the filling rate of three working faces after filling was investigated, and the ground subsidence was calculated based on numerical software, and the simulation results were verified by field measurement. Finally, the influence of gangue filling mining on the surface buildings is preliminarily evaluated based on relevant deformation indexes. The results show that the maximum filling rate of xinyuan coal mine after filling mining is 73% and the minimum is 36%. The surface subsidence curve calculated by numerical method matches the measured data points, which proves the reliability of simulation work. The maximum possible surface horizontal deformation value of the three simulated working surfaces is 0.15 mm/m, the maximum possible surface tilt deformation value is 0.35 mm/m, and the maximum possible surface curvature value is 0.0022 mm/m2. These deformation parameters are all smaller than the relevant grade ⅰ deformation index, and the effect of gangue filling mining on ground buildings is very small. It is feasible to predict and evaluate the surface deformation caused by gangue filling mining in advance by using this numerical simulation method.

In order to find out the causes of the landslide on the east side of the surface plant of Halagou coal mine, the geological conditions, seepage, and deformation characteristics of the landslide were investigated by means of on-site geological survey, hydrogeological drilling and surface displacement monitoring, and the mechanical mechanism of the landslide was analyzed by a numerical simulation method. The results show that a nearly EW-oriented paleogully is developed at the bottom of the Quaternary loose layer on the east of the landslide with two branches in the upstream. The surface water of Shendong Lake and the daily ecological irrigation water supplies the paleogully basin in large quantities, resulting in a rise of groundwater level and the formation of a discharge area at the foot of the landslide slope; Due to the leakage of a large amount of surface water, the groundwater seepage velocity increases, the water level rises, and the pore water pressure increases, and therefore the matrix suction decreases and the shear strength of the landslide soil decreases, resulting in the reduction of the anti-sliding force. A large amount of water seepage at the slope increases the weight of the slope and generates downward osmotic pressure, resulting in the increase of sliding force. And therefore, the landslide was induced. As the water temperature increases, the landslide stability coefficient decreases. Three drainage wells were constructed at the foot of the slope. After pumping, the groundwater level of the slope was reduced, and the leakage point of the upper ditch was treated. At present, the deformation of the landslide has been effectively controlled.

In order to solve the problems of high filling cost and low filling efficiency of the coal mining under buildings,water bodies and railways, we mainly use mineral powder, a low-cost hydraulic cementitious material, supplemented by a small amount of gypsum and silicate clinker, an early-setting, low-cost cementitious material is obtained that it is suitable for high-efficiency solid backfilling. We also analyzed the size grading of gangue and the curing mechanism of the cementitious material, the optimal ratio of cementitious materials is obtained through designing orthogonal experiments, when gypsum content is 5%, cement clinker content is 25%, and mineral powder content is 70%, the filling body can be demoulded in a short time, it shows that the degree of hydration reaction of the cementitious material is the best at this content, the active ingredients of the mineral powder can react in the early stage to form hydraulic ettringite (AFt), which promotes the formation of the strength of the filling body, The 7d and 28d strength of the filling body can reach 3.48MPa, 5.11 MPa After curing, it is slightly lower than the 7d and 28d forming strength of 425# sulphoaluminate double fast cement, but it has obvious advantages in cost. Combined with industrial applications, we analyze the actual filling effect, the working resistance of the hydraulic support and the observation data of ground subsidence, it shows that the cementitious material plays a positive role in improving filling efficiency and strengthening roof management.

Abstract: After the uniaxial compression experiments and acoustic emission monitoring were carried out on coal-concrete connectors with different water content, and the mechanical properties and acoustic emission characteristics of connectors were explored. The following conclusions can be drawn: 1) water has a significant influence on the compressive stage, failure stage and post-peak stage of the characteristic cracks of the stress-strain curve of the coal-concrete joints. The presence of water reduces the cohesion between samples, reduces the brittleness and enhances the plastic shape.2) With the increase of water content, the failure mode of coal rock combination changes from tensile failure to shear failure, and the plastic deformation is significant. 3) The acoustic emission characteristic curve corresponds well to the stress-strain curve. With the increase of water content, the peak position of acoustic emission AE count is advanced, and the structural failure of the composite sample occurs in advance. The peak value of AE count gradually decreases and the brittleness of the composite sample decreases. The research results have a certain reference value for the stability of the connection between coal pillar dam and artificial dam of coal mine underground reservoir.

Large-scale underground mining will lead to rock cover movement, deformation and even destruction, and in the surface to form a large-scale subsidence area, the formation of bad foundation, in the subsidence area to build construction (structure) structure will have a greater security risk, master the construction (structure) structure and surface movement deformation related laws is the premise to ensure building safety. In this paper, the subsidence area buildings as the research object, respectively, using 3D printing technology to simulate the structure of buildings, sandstone materials to simulate the structure of rock and earth, the construction of buildings and rock and rocks coupling physics simulation experiments, the study of coal seam mining caused by the ground movement deformation of the top of the building on the top, the top of the first floor and other parts of the response. The results show that 3D printing technology can better realize the building simulation matching geometric similarity and the mechanic strength, and the factors influencing the force of the 3D printing building simulation material mechanics: the filling rate> material properties> the printing angle > the printing thickness, and the corresponding relationship between the building and the surface movement deformation is constructed. The research results will help to grasp the mechanism of mining settlement-causing construction (structure) structure and the relevant laws of building damage and surface subsidence, which is of great significance for liberating the "three-down" pressure coal and ensuring the safety of the ground construction (structure) structure in mining areas.

To explore the suppression rules of gas explosion with typical salt powder and salt solution. In this paper, we researched the influence of NaCl, KCl powder and NaCl solution on the deflagration flame propagation characteristics of methane/air premixed gas and built a stainless steel flame equipped.The results show that laying NaCl and KCl salt powder can inhibit the propagation of methane deflagration flame, and the deflagration pressure and average flame propagation speed are lower than those of the blank control group. When the laying surface density of NaCl and KCl salt powder is 150 mg/cm2, the average flame propagation velocity of the two salt powders attenuates the most. With the increase of the powder laying length, the inhibition and promotion of flame propagation are enhanced, but the degree of inhibition of KCl is more evident than that of NaCl. When laying out the NaCl solution, the deflagration flame pressure are below the blank group. The velocity showed a continuous decreasing trend; as the laying length of the solution increased, the average flame propagation velocity and the peak pressure of deflagration decreased gradually.

At present, the design of heat transfer effect of heat pipe heat exchanger for mine return air has great deviation from the actual application.Threlkeld method based on enthalpy difference is used to analyze the heat transfer coefficient and fin efficiency under the mine return air in wet conditions. Furthermore, the heat transfer model of single heat pipe heat pipe is established, and the heat transfer analysis of heat pipe heat exchanger is carried out by the method of pipe by pipe .The results show: In practical application, the total heat transfer coefficient of the heat exchanger has little change, so it can be regarded as fixed heat transfer coefficient. There is a big difference between the mine return air and the surface temperature of heat pipe fins on the return air-side of heat exchanger, so the surface temperature of the return air-side of heat exchanger should be greater than 0℃.

In order to explore the transient characteristics of the stall flow signal of the contra-rotating fan, the wavelet analysis method with strong ability to identify the instantaneous characteristics of the flow signal is introduced into the analysis of the stall characteristics of the contra-rotating fan , and a stall diagnosis method combining FFT technique and wavelet-time-frequency analysis is proposed. Firstly, based on the outlet throttle model, numerical simulation and analysis of the 3-D unsteady flow inside the contra-rotating fan under a stall condition is carried out; Secondly, the static pressure signal in the flow field of the fan is processed and analyzed by using the proposed stall diagnosis method. The results show that the contra-rotating fan enters a stall state after 10 rotation period, which occurs with the appearance of leading edge overflow and trailing edge backflow. In addition, the FFT technique determines from the perspective of frequency domain that the stall characteristics are manifested as the appearance of 70Hz and 140Hz frequency components, while the wavelet-time-frequency analysis found that the contra-rotating fan began to appear 70Hz and 140Hz frequency components from the perspective of time-frequency domain at the 10th rotation period. It is proved that the method proposed has a good performance for the diagnosis and analysis of the stall characteristics of the fan.

Aiming at the problems of short cruising range and difficulty in climbing in the existing coal mine inspection robot with rail-mounted belt conveyor, a walking mechanism combining track and wire rope traction was designed. First, according to the technical requirements of the inspection robot, the overall plan of the inspection robot is studied. Then the structure, walking mechanism, track installation and data acquisition modules of the inspection robot are designed. A virtual prototype model of the inspection robot is established in the ADAMS software, and its displacement changes in the horizontal and tilting motion states are simulated. The robot can run stably in the horizontal direction along the track; there are slight fluctuations in the vertical direction and the horizontal side swing direction, but both meet the requirements; finally, a data acquisition and transmission module is built, and the information acquisition test of the indoor environment shows that: the data acquisition and transmission module can work stably and normally. Therefore, the robot can provide a reference for monitoring the operation status of underground equipment in coal mines.

As a traditional survey and design enterprise, China Coal Tianjin Design Engineering Co., Ltd. closely follows the great changes in the coal industry and actively responds to the "3060" major strategy. Combined with the development of diagnosis and optimization of production mine system, it summarizes the main principles that should be grasped, puts forward the "four times and five steps" working method, the "three comparisons" working principle and three characteristics that should be grasped in optimization, It provides a new way for the company's business transformation and development. With the goal of safety, efficiency, intelligence, green and low carbon, we will gradually explore a path to realize the advanced and advantageous production capacity of coal, and achieve win-win results for both sides on the basis of providing value-added services for coal mines.

The goal of carbon peak and carbon neutrality is a major strategic decision made by the Party Central Committee and the State Council to coordinate under the overall international and domestic situations. Shanxi Province, a typical resource-based region, have to upgrade and reform the coal mine enterprises imminently and imperatively. Based on the development of coal mine enterprises in Shanxi province and combined with the produces of representative coal mine enterprises, making full use of modern technologies, the Internet of Things, big data and cloud computing, to deeply integrate with traditional mines, and establish and improve the basic framework of coal mine smart mines.