With the increasing depth and intensity of coal mining in China, roadway rockburst has become a threat to the safe and efficient production of coal mines that cannot be ignored. As the last barrier of the coal mine rockburst prevention and control, support is crucial for the protection of roadway rockbursts. The article summarizes the important research results achieved in rockburst roadway support technology in the past 10 years, and introduces the main forms and support materials of rockburst roadway support. Finally, the development direction of the rockburst roadway support technology is prospected.

In order to solve the problem of strong deformation of surrounding rock of fully gob driving roadway without coal pillar in shallow buried island working face, the overburden structure model of gob driving roadway is established, the overburden structure, ground pressure characteristics and roof structure fracture form of fully gob driving roadway are analyzed, and the influencing factors affecting the stability of surrounding rock of fully gob driving roadway are determined. Using theoretical analysis and numerical calculation methods, the compressibility of the support body, the width of the filling body beside the roadway and the support resistance of the filling body are determined, and the idea of coordinated control of surrounding rock such as strengthening the bearing performance of the anchorage system, strengthening the top wall structure and flexible support in the roadway is put forward. The results show that: firstly, the new "three high" bolt, large-diameter and high prestressed anchor cable and accessories are used to strengthen the support, so as to effectively control the deformation and failure of the shallow and deep parts of the roadway; At the same time, it is necessary to strengthen the coordinated control of roadway roof, and realize the effective support of the roof by strengthening the support strength and scope of roadway wall coal body; Finally, the advance temporary support in the roadway can resist the fracture and subsidence of key overburden and avoid the strong deformation of roadway roof. The three support modes should coordinate with each other in time and space, so as to realize the coordinated control of the three support modes on the roadway along the goaf. The research results have been verified in the field. The surrounding rock and wall structure of the roadway remain stable, the deformation is controllable, and the roadway support effect is good.

In this paper, through the combination of theoretical analysis and numerical simulation, it is concluded that the particularity of coal pillar size should be fully considered when the complex roof roadway is disturbed. In the design of roadway support, we should pay attention to the control of roof rock and increase the support surface area as much as possible. Taking Xinyuan coal mine roadway as the research object, according to the theoretical calculation, the minimum size range of coal pillar is 6.07-7.12m. On this basis, through numerical simulation of stress and deformation characteristics of coal pillars with different sizes, it is concluded that when the width of coal pillar is 8m, the safety of roadway under the influence of secondary mining advance can be ensured, and the bearing capacity of coal pillar can be fully utilized. The research results have been applied in 2203 track crossheading of Xinyuan coal mine, and good surrounding rock control effect has been achieved .

In order to solve deep mining influence area roadway surrounding rock control problem in the Shuguang coal mine, taking west concentrated return alley as engineering background, the pull-out test of bolt was carried out underground, it was found that the anchoring force of the bolt was obviously lower, the field test showed that the influence of mining aggravated the deterioration of surrounding rock structure, and decreased the strength of coal and rock mass obviously, the strength of coal seam and mudstone decreasing by 31% and 19% respectively, the mining stress caused the strength of the surrounding rock to decrease, aggravated the deterioration of its structure, leaded to the loss of bolt anchoring force, weakened the effectiveness of bolt support to control the surrounding rock, and was the internal factor of the strong deformation and destruction of the roadway, the field investigation found that the bolt material had low strength, small prestress and bad compatibility of support components, which weakened the control function of bolt support system for surrounding rock, and was the external cause of instability and failure of roadway. Numerical simulation was used to study the effect of shotcrete timing on the stress and displacement of bolt tail, and the mode of thin shotcrete followed by thick shotcrete was determined. Based on the broken and loose characteristics of the surrounding rock of the return air roadway in the mining-affected area, the advanced grouting combined with high-prestress bolting and shotcreting technology was put forward, and the grouting and bolting and shotcreting reinforcement schemes and parameters were given, it provided reference for stability control of roadway surrounding rock under similar geological conditions.

Aiming at the problem of large deformation of roadway, based on geomechanical testing, the characteristics of parallel mining roadway and the difficulties in rock control are analyzed. The basic top beam model is used to calculate that the pressure relief height of the deep hole , and the pressure relief of the mining roadway, the pressure relief of the floor in the different roadway and the grouting surrounding rock remodeling technology are combined to form the "deep unloading shallow plastic" surrounding rock comprehensive control technology of the parallel mining roadway. The monitoring results of roadway ground pressure show that the coal pillar stress is stable in time after the mining increase.Basically, there is no suspended roof on that day, which effectively reduces the impact of mining advance pressure on the adjacent main roadway; The maximum deformation and separation value of roadway is stable.The surrounding rock control of main roadway is well realized.

In view of the strong ground pressure behavior of roadway under the condition of shallow and deep hard thick roof, the evolution law of full cycle mining stress before and after mining and the evolution characteristics of deformation and failure of roadway surrounding rock were studied by using a variety of field measured data. The results show that the evolution law of full cycle mining stress before and after mining in the working face shows significant stage change characteristics. The influence of mining in the leading stage is small, and the ground pressure in the lagging stage is strong. The stress on the bolt at the lower part of the coal pillar wall is the most significant, with a maximum increase of 17.3kn. The vertical stress of the coal pillar changes most strongly in the lag working face stage, and the peak stress is mainly distributed within the range of 8~14m of the coal pillar. The evolution law of the coal pillar stress is that the goaf side gradually transfers to the auxiliary haulage roadway, and the peak stress of the coal pillar finally stabilizes at 10.4mpa. When the lag working face distance is greater than 405.6m, it tends to be stable with the movement of roof rock layer, and the change of mining stress is also gradually stable. Combined with the deformation characteristics of auxiliary haulage roadway under mining stress, the control idea of strengthening support in weak links is put forward, and reasonable roadway support countermeasures are formulated, in order to provide some guidance for surrounding rock control of dynamic pressure roadway under similar conditions.

Aiming at the problem of dynamic load failure of bolt support plate in deep mine roadway in Mongolia and Shaanxi, a drop hammer impact test-bed of bolt support plate is built in the laboratory, three kinds of commonly used bolt support plates in deep mine in Mongolia and Shaanxi are selected, the static and dynamic load mechanical properties are tested by servo pressure test machine and drop hammer impact test machine, and the static and dynamic load mechanical properties of three kinds of support plates are studied. The results show that the structure and thickness of the supporting plate will significantly affect its static and dynamic mechanical properties. The supporting plate with reasonable structure and large thickness has higher static load-bearing capacity and impact resistance. Under static load, the bearing capacity of a, B and C supporting plates are 212kN, 231kn and 276kn respectively, and the deformation is 14mm, 13.9mm and 12mm respectively. The bearing capacity of C supporting plate is high, mainly due to the reduction of arch height, and the four corners are not obvious; Under the action of impact energy, the peak value of the impact force of the supporting plate is slightly higher than the static load bearing capacity. The supporting plate with high bearing capacity has strong impact resistance. After being affected by the impact energy, the supporting plate is dominated by structural deformation, and the peak value of the impact force changes little, while the supporting plate with low bearing capacity has a sharp increase in the impact force of the supporting plate under high impact energy due to the collapse of the arch structure.

In view of the large variation of coal seam thickness in fully mechanized caving face and the waste of coal resources caused by excessive section coal pillar, the 6107 working face of Hongshuliang Coal Mine is taken as the engineering background. Based on the thickness change of coal seam, the 6107 working face is divided into three regions. Combined with the methods of theoretical analysis, numerical simulation and field test, the widths of the optimal section coal pillars in the western region, the central region and the northern region of the 6107 working face are 14 m, 19 m and 11 m, respectively. The auxiliary roadway needs to be arranged straightly, and the width of section coal pillar in three regions is comprehensively studied. Finally, the overall section coal pillar width of 6107 working face is determined to be 17 m. The sub-regional support technology controls the stability of roadway surrounding rock. The research results have been successfully applied to engineering practice, providing a useful reference for roadway layout under similar conditions.

Abstract: Distributed photovoltaic power generation system has intermittency and fluctuation, and there is a harmonic source represented by power electronic equipment in the system. After it is connected to the coal mine distribution network, it will have many adverse effects on the power supply quality.This paper expounds the positioning of distributed photovoltaic power generation system, and defines its operation mode after being connected to coal mine distribution network. From the changes after the distributed photovoltaic power generation system is connected to the coal mine distribution network, its impact on the coal mine distribution network is analyzed. It is obtained that the change of power flow distribution, the fluctuation of photovoltaic power and the injection of harmonic source are the main factors of adverse effects, as well as the boundary conditions of adverse effects. Based on the analysis of the characteristics of coal mine distribution network, the grid connection design principle of using distribution network load and minimum three-phase short-circuit current to limit the adverse effects is summarized.

Railway loading method of coal mine is an important component of the mine railway transport, the Railway loading method selection directly affects the coal Railway capacity, combining with the domestic part of the mine railway station as examples, Contrast and analyze the three methods, Determine the selection method of loading mode under different conditions,Forecast the future development of coal mine railway loading mode.

Abstract: In order to liberate the staff from the strong noise environment, by analyzing the function and environment of the coal mine air compressor room, this paper designs an air compressor room composed of a PLC-based remote monitoring system and an autonomous inspection robot system. The human-on-duty intelligent inspection system realizes the remote control of air compressors, the linkage and automatic rotation of multiple air compressors, and the regular inspection of the inspection robot.

At present, there are cross transportation problems in many open-pit mine transportation systems in China, such as Pingshuo East open-pit mine, Pingshuo Anjialing Mine, Xiwan open-pit mine and Hequ open-pit mine. In order to avoid the potential safety hazard caused by plane crossing of transportation system, most open-pit mines adopt independent stripping transportation system and raw coal transportation system. However, the independent transportation system directly leads to the sharp increase of stripping transportation distance and high transportation cost, which seriously affects the economic benefits of open-pit mines. Years of practice in traffic management system has proved that proper setting of interchange facilities is the most effective solution to improve the overall transport efficiency. This paper introduces the application of steel box girder bridge in the overpass project of Shengli West No.2 open-pit mine. Through the study of bridge layout, structure analysis and benefit calculation, it is proved that the application of steel box girder bridge in the overpass project of Shengli West No.2 open-pit mine is technically feasible and the economic benefit is obvious. It can be used as a reference for solving similar cross transport problems in open-pit mines.

Aiming at the problem of the design scheme of anti scour roof blasting in the withdrawal channel of nalinhe No. 2 mine, from the perspective of stress blocking and positive protection of the withdrawal channel, the design scheme of roof blasting is designed and optimized, and the obvious technical advantages of "high + low" blasting are analyzed and verified. First, in terms of blasting induced cracking and crushing, the "high + low" series one-time blasting and the superposition of vibration stress waves enhance the cracking and block crushing effect in the blasting area, reduce the change gradient of blast hole stress in the blasting affected area by 37.5% - 40%, enhance the function of blocking high stress transmission, and avoid the superposition of mining stress and coal pillar concentrated stress impact disaster force source; Second, in terms of blasting scale, the stress transmission path within the range of short-range rock stratum (10 times mining height) affecting the impact behavior of the working face is eliminated, the pressure relief blind area is avoided, the blocking of the whole layer is realized, and a positive protective effect is formed on the main withdrawal channel.

In order to solve the problem of optimal design of roadway support of water rich and weakly cemented roof in western coal mine, through the experimental study of coring rock samples of water rich and weakly cemented roof in western coal mine, it is concluded that the rock samples reach the water saturated state after immersion for 24 hours, are prone to expansion deformation and delamination in the vertical direction, and the uniaxial compressive strength is 18.9% lower than the normal. According to the test results and the actual geological conditions on site, three targeted roadway support optimization designs are proposed: section optimization, roof support anchoring force enhancement optimization technology and roadway gradient anchoring optimization technology. The field observation results show that after the optimization of roadway support, most of the shallow and deep separation layers of the roof are distributed within 0 ~ 10mm during roadway excavation, and the increased load of the bolt (cable) of the surrounding rock of the roadway is mostly distributed within the range of 11 ~ 30KN, within the bearing capacity of the bolt and cable. The ground pressure is not obvious during roadway excavation. The safe support of roadway is realized, and the optimal support practice demonstration is carried out for the roadway support of water rich and weakly cemented roof in western coal mine.

In order to solve the problems such as the influence of secondary mining on the return air chute of 110 working face in Mataihao coal mine and the difficulty of the original support in maintaining the stability of the roadway, the methods of field investigation, engineering geological analysis and borehole peeping are adopted. It can be seen that the roof and floor of the coal seam are mostly soft rock, which is easy to soften and deform in case of water, the stress environment is complex, and the original support cannot be effectively coupled with the surrounding rock are the main reasons for the deformation of the surrounding rock of the roadway. Numerical simulation is used to study the influence of mining on roadway stability in 108 and 110 working faces, and an optimization scheme of high-strength and high prestress yielding anchor mesh support is proposed, which is verified by numerical simulation and underground industrial test. The results show that the optimized support system can effectively couple with the surrounding rock, give full play to the active support effect of high prestressed bolts, enhance the mechanical properties of the surrounding rock, greatly improve the roadway support efficiency and significantly reduce the surface displacement. The anchor mesh cable coupling support system of 110 return air chute in Mataihao coal mine is established, which provides technical support and safety guarantee for safe and efficient production of the roadway.

The deformation control of the surrounding rock in the roadway of the deep high stress soft coal seam is of great significance to the safe and efficient production of the mine. Based on the engineering problems of the No. 3 coal seam roadway in Changping Coal Mine, such as the soft coal body, the weathering and fragmentation of the roof mudstone, and the severe deformation of the roadway retention caused by the large burial depth and strong dynamic pressure. The failure characteristics of the surrounding rock in the soft and broken roadway under the influence of dynamic pressure are analyzed. It reveals the failure and instability laws of different areas in the shallow and deep parts of the roadway, the three-in-one surrounding rock coupling control technology system of "roof cutting pressure relief + soft coal body reaming anchoring + roof high-strength support" was proposed, and an industrial test was carried out in the 53082 roadway. The results show that the technology and device for increasing the anchoring force of the hole bottom reaming can increase the anchorage performance of the roadway side coal by 84.6-114.3%, and effectively improve the support effect of the roadway side anchor cable; the coupling of roof cutting pressure relief and high-strength support is suitable for the safety of soft and broken roadway and the stability of surrounding rock. The research results can effectively control the strong deformation of the roadway under the influence of dynamic pressure, and significantly reduce the repair work of the roadway.

In order to study the feasibility of drainage and decreasing water for aquifer of the upper limestone of Taiyuan Formation at the bottom of the first mining face in the deep mining area in Shunhe Coal Mine, based on the systematic analysis of the geology, hydrogeology and mining conditions of the first working face 2401, a new idea is put forward to prevent and control the limestone water in the bottom floor of the first working face by means of drainage and reduction water pressure. Therefore, the design implementation of the three drainage bore hole and two monitoring of underground drainage water test, the draw down water - time matching method and the line graphic method were used to match and calculate for drainage water phase and water level recovery phase , integrated to obtain the hydrogeological parameters of aquifer, the relative error basic meets the actual needs. Based on the results of drainage test, it is determined that the aquifer of the upper limestone of Taiyuan Formation at the bottom of the first wording face can be drained and lowered. Two kinds of drainage water schemes were designed and 8 drainage holes and 4 monitoring holes were designed. Through the verification of 7 actual drainage holes in the the transport roadway of 2401 working face, it was found that the water pressure drops obviously, and the drainage effect reaches the expected target. The results show that the aquifer of the upper limestone of Taiyuan Formation at the bottom of the working face has the ability of drainage. The research methods and ideas have a good reference value for the control of limestone water at the bottom of other working face under similar geological and mining conditions.

In order to solve the problem of low equipment withdrawal efficiency and high safety risk in the fully mechanized mining face of Wangpo coal mine, and achieve the goal of reducing personnel, in the process of equipment withdrawal in 3314 fully mechanized mining face, innovation and optimization are carried out from the aspects of improving the final mining support technology, changing the withdrawal equipment, improving the withdrawal technology and optimizing the auxiliary transportation system, new materials, new processes and new equipment such as "shotcrete anchor" support (shotcrete, grouting and anchor cable reinforcement) technology at the stoping line, full section high-strength polyester fiber mesh, support withdrawal and direction adjustment platform, continuous and uninterrupted transportation from the shaft bottom yard to the withdrawal channel are adopted in the first time. It has changed the traditional retraction mode with winch as the main retraction equipment and track transportation as the main auxiliary transportation mode, completed the equipment retraction of 3314 fully mechanized mining face safely and efficiently, achieved good application effect, and explored a new path for the equipment retraction of fully mechanized mining face in Wangpo coal mine and other similar conditions.

Rocker gear box is the core power transmission mechanism of shearer, and its reliability is of great significance to the efficient production of coal. The fault mechanism and fault diagnosis method of rocker arm gearbox of shearer are summarized in this paper. Firstly, the fault mechanism of rocker gear box bearing and gear under different fault states is summarized. Secondly, the main problems of existing fault diagnosis technology of shearer are analyzed. Finally, it is pointed out that future research should be devoted to accurate fault mechanism, composite fault analysis, weak fault identification, basic data collection, algorithm fusion innovation and multi-source information utilization, so as to provide reference for fault diagnosis of rocker arm gearbox.

Aiming at the problems of large retaining size of Huangyuchuan Coal Mine and the difficulty of sealing holes by grouting in the local soft and broken surrounding rock of some roadway, the size of section coal pillar was optimized by means of theory and numerical simulation, and a grouting sealing device suitable for the conditions of soft and broken surrounding rock was developed. The results show that the reasonable width of coal pillar in Huangyuchuan coal mine section is about 18m, which can not only ensure the effect of coal pillar protection, but also reduce the waste of resources due to coal pillar retention. The field test results show the effectiveness of the new grouting sealing device, and it has good grouting sealing effect on soft and broken surrounding rock. This paper provides a reference for section coal pillar retention and grouting hole sealing technology under similar conditions, which has certain theoretical and engineering reference value.

Aiming at the big data analysis of hydraulic support resistance monitoring of fully mechanized mining face, the prediction and early warning of incoming pressure and the influencing factors of incoming pressure, a mining pressure prediction model based on big data is proposed. According to the FLAC3D numerical simulation and the actual monitoring results of Liuzhuang Coal Mine , divide the push mining into three stages: stable push mining, shutdown maintenance, and rapid push mining. The following conclusions are drawn: the prediction accuracy of the incoming pressure value of big data is about 65.5%, and the prediction accuracy rate of the incoming pressure range is about 51.7%. ; The larger the mining distance in a single working day, the greater the subsidence of the roof, and the greater the pressure value of the support; in the stable mining stage of the working face, the number of times of pressure is less, and the step distance of the pressure is large; In the rapid mining stage, the pressure is frequent and the pressure step is small. According to the change of the pressure in the corresponding stage of mining, the predicted correction value K of Liuzhuang Mine is ±1.5.

To obtain the risk of rockburst, based on the geological conditions of Gengcun Coal Mine, the variation of stress and activation of fault were studied when mining in hanging wall or footwall of reverse fault with numerical modeling and similar simulation experiment. By establishing numerical model, the working face was arranged in hanging wall, the variations of stress and slips at different positions of the fault plane were studied during mining, and the activation degree of the fault and rockburst risk were obtained within the distance of 80~10m from fault to working face. The stress distribution and deformation evolution were studied during mining in footwall. By similar simulation experiment, the displacement of the plane and the fault activation were studied during mining in footwall of the reserve fault. Through the comparative analysis of the results of the two methods, it is shown that the risk of fault activation during mining in footwall is higher than in hanging wall. When the working face is 10m away from the fault, it is most likely to lead to fault activation and then rockburst, and the activation area is 20~ 30m above the coal. This study provides a theoretical basis for the prevention of rockburst in mining.

In view of the phenomenon that coal mine water accidents threaten the safety production of mining enterprises in China in recent years, the data on water disaster accidents from 2008 to 2021 published by the national and local mine safety supervision bureaus and the coal mine safety net were collected and analyzed. The accident data is analyzed from the perspective of water accident grade, time, space and mine scale using mathematical statistics, and the occurrence law of water accident is discussed. The impact of raw coal production on the million-ton mortality rate is analyzed, and the million-ton mortality rate forecast for 2022 and 2023 is made and according to the characteristics of the flood accident, put forward the prevention and control suggestions. The results show that relatively large and above water disaster accidents are the focus of water disaster prevention and control in coal mines. Spatially, coal mine flood accidents occur most frequently in North China, Northeast China and Southwest China. In terms of time, the water disaster accident occurs most frequently from March to April, July to August, every day from 23:00 to 1:00, from 7:00 to 9:00, from 15:00 to 17:00, and from 17:00 to 19:00 has more flood accidents. Water disasters are more common in small mines. There is a long-term inverse relationship between raw coal production and the mortality rate of one million tons. It is expected that the mortality rate of one million tons will drop to 0.041 and 0.030 in 2022 and 2023.

Abstract: In shaft construction, the cutting-type roadheader mainly relies on the picks installed on the cutting drum to break the rock. The quality of the rock-breaking performance of the picks directly determines the performance of the roadheader. This paper uses the finite element method to simulate the rock-breaking process of a single pick, and analyzes the change law of the rock-breaking load under the key parameters of cutting thickness, cutting angle, tooth tip cone angle and cutting speed; Orthogonal test method to study the influence of these four key parameters on the specific energy of rock-breaking. Through intuitive analysis and variance analysis of the test results, the primary and secondary order of the factors affecting the specific energy of rock-breaking of the pick and the rock-breaking of the pick are obtained. Optimal configuration of parameters. The research results can be used as a reference for improving the rock breaking efficiency of picks.

Open-pit coal mine belongs to semi-open space, which will produce a lot of dust in coal mining. The transportation link is line dust source, which lasts for a long time and contributes a lot to dust production. In order to study the dust migration law of truck transportation in open-pit mine, taking Anjialing open-pit mine as the research object, this paper analyzes the variation law of dust concentration in transportation link of Anjialing open-pit mine by means of theoretical analysis, numerical simulation and field monitoring, and puts forward dust removal suggestions. The results show that the dust concentration in the transportation process does not exceed the relevant national standards in most of the time, and the dust pollution area caused by truck driving is concentrated in the contact position between tires and the ground. Dust accumulation is easy to occur at the gap between the front and rear wheels of the truck. The highest concentration in this area is 4.9mg/m3. The highest concentration of dust is 1.62mg/m3 at the height of 3m at the tail of the truck, and the maximum diffusion concentration is 1.28ug/m3 at the height of 7m, 20m away from the tail of the truck. The research results can put forward targeted dust control measures for dust accumulation locations and diffusion areas in transportation links to achieve effective dust control.

In order to explore the influence of different combinations of parameters (turning angle, blade pitch and airflow velocity) on the mist removal efficiency and pressure loss of the streamlined mist eliminators used in the mining wet dust removal fan, the three-dimensional numerical simulation of the flow of the air containing droplets in the streamlined demister was carried out by using FLUENT software. By introducing evaluation parameters to optimize structural parameters, a demister structure with high mist removal efficiency and low power consumption of dust removal fan is obtained. The results show that: with the decrease of the turning angle of the demister and the blade pitch, the mist removal efficiency and the pressure loss show an increasing trend. When the droplet size is greater than 10 μm. the mist removal efficiency increases with the increase of airflow velocity; When the droplet size is less than 10 μm, the mist removal efficiency decreases with the increase of airflow velocity. When the blade pitch is reduced from 40 mm to 20 mm, the pressure loss increases by only about 15%; However, when the speed increases from 2m/s to 6m/s, the pressure loss increases by about 5 times. Therefore, the influence of blade pitch on pressure loss is significantly lower than that of velocity. When the mist eliminator has the same mist removal efficiency, the mist eliminator with the parameters θ=90° and B=20 mm has the best performance. At this time, the evaluation parameters of the demister remain low, which can reduce the power consumption of the dust removal fan. The evaluation parameter relates the power consumption of the dust removal fan to the structural design of the mist eliminator, and provide an idea for the multi-parameter combination optimization design of the mist eliminator.

In view of the fact that a large number of surface cracks and fracture zones caused by coal mining subsidence in ecologically fragile areas have a significant impact on the content, distribution and movement of soil moisture in the mining area, and exacerbate the problems of soil and water loss and soil desertification, this paper takes the soil, aeolian sand, loess, clay and fly ash in the coal mining subsidence area and non subsidence area in Shendong mining area as the research object, through on-site sampling, in-situ monitoring The backfilling method of mining ground fissures in the study area is studied by combining indoor experiment and numerical simulation. After simulating the soil water movement of each reconstructed soil after backfilling the ground fissures according to the "three-step method", It is concluded that the soil water movement of the reconstructed soil with the selected backfill components uniformly mixed according to the mass ratio of 1:1:1:2 is the closest to the in-situ monitoring results of the soil in the non subsidence area, and the water retention performance of the deeper soil is slightly better than that of the undisturbed soil in the non subsidence area, which is the best backfill reconstructed soil.

High-locality landslide has the characteristics of hidden disaster process, rapid occurrence, dynamic impact and long runout distance, which seriously endangers the safety of people's lives and property. Taking the Guinsaugon landslide as an example, based on the engineering geological conditions of the study area, and landslide movement path zoning has been carried out. What’s more, the landslide movement process is inversed through the combination of the basement rheological model friction voellmy friction model. The results show that the movement duration of guinsaugon landslide is about 90s, and the maximum movement speed is about 52.95m/s at the horizontal distance x = 1896m. The average thickness of the accumulation body is about 15-20m, and the farthest movement distance is about 4100m. The calculation results are similar to the actual situation. Finally, the movement mode of debris flow in guinsaugon landslide is discussed and analyzed. The above research provides reference for similar high-locality landslide disaster research in China.

With the depletion of resources and the adjustment of energy structure, the number of coal mines closed in China is increasing day by day. In order to effectively deal with the problems of large-scale groundwater pollution caused by closed pit mines, affecting the surrounding environment and normal production and life, etc, this paper introduces the rebound process and pollution formation mechanism of mine water after the mine is closed, expounds the research status of mine water pollution mechanism from the perspective of pollution source and pollution channel, and summarizes the research status and existing problems of prevention and control technology. Finally, the types of polluted mine water in different regions of the country are summarized, and some treatment technologies and processes are given. It is proposed that the treatment of polluted mine water should be adjusted according to local conditions, and at the same time, the mine water should be classified and utilized, so that the mine water can be utilized. The results show that the pollution source of underground water in closed pit mines is mainly the result of the combined action of physics, chemistry and microorganism, and the current research is still lacking; Prevention before pit closure is the most economical and effective key stage to deal with groundwater pollution, which should be focused on. The establishment of information management system, monitoring and forecasting system and the development of new treatment materials and technologies for polluted mine water are important research directions in the future.

In view of the characteristics of Shenhua coal liquefied asphalt (CLA), such as high softening point, high aromaticity, high carbon content and easy polymerization or cross-linking, spherical activated carbon with specific surface area over 2,000 m2/g was prepared by 700℃ high temperature spray method and KOH activation method using CLA as carbon source. CLA, spherical carbon (SC) and spherical activated carbon (SAC) were characterized by scanning electron microscopy (SEM), low temperature nitrogen adsorption (BET), infrared spectroscopy (IR), X-ray diffraction (XRD) and Raman spectroscopy. It was found that the process of atomization, spheronization, non-melting oxidation and carbonization can be completed in one step by high temperature spray, avoiding the problems of low spheronization temperature, easy adhesion, deformation and crushing of microspheres when the temperature rises that occur in a conventional preparation process, thereby obtaining an activated precursor with spherical morphology and relatively uniform structure and size. Under condition that KOH is in a mass ratio of 1: 2 and activated for 90 mins at 700℃, SC can produce spherical activated carbon (SAC) with specific surface area of 2,340 m2/g. When the current density increased from 0.5A/g to 20A/g, the specific capacitance decreased from 243.36F/g to 226.08F/g in a two-electrode electrochemical performance test. The capacity remained unchanged after 10000 cycles at a current density of 5A/g.

To deal with the tearing or rupture problem occurred during the movement process of the conveyor belt in the power plant, a detection device based on machine vision and image recognition was designed according to the working environment and testing requirements. The grid line laser, used as structural light, was irradiated under the conveyor belt surface, and the real-time images of the belt were acquired through the high resolution industrial camera. The belt tearing was identified by feature of gird line in images, which cost only 40 ms, the recognition accuracy rate is as high as 96%, and the false alarm rate is only 2%. Compared to traditional detection methods, the whole time is shortened greatly, and the conveyer belt does not need stop, which ensures the safe and efficient production of the conveyor belt, reduces the accident rate effectively.

This paper takes Shanxi coking coal as the research object, based on the main coal field exploration results, relevant geological data and actual coal chemical achievements in China, and using the theories and methods of coal geology, coal petrology, coal chemistry and coal chemical engineering, expounds the coal rock and coal quality characteristics of coking coal in China at the present stage, and discusses the influence of geological factors on the coking characteristics of coking coal from the aspects of coal rock composition, coal quality change characteristics and sedimentary environment characteristics of the study area. The composition of macerals, the types and proportion of sub components and the differences of coal quality characteristics in coking coal are closely related to the coal forming environment, which is mainly affected by the changes of the nature of coal forming basin, provenance components and sedimentary environment. The nature of coal forming basin base and provenance and the change of sedimentary environment directly affect the coal quality characteristics of coking coal, and the sedimentary environment also affects the type, sub component content and composition of macerals. Finally, the same kind of coal shows different coke properties. In the process of coal formation, the content of vitrinite in coal formed during water invasion is significantly higher than that in coal formed during water regression. When the coal facies are divided, the content of coal vitrinite formed in the low-level swamp environment is always the highest, and the wetland herb swamp wet forest swamp facies is the most typical; The coal formed in the high-level protrusion swamp environment is mainly inertinite, and the dry forest swamp facies is the most typical. The metamorphic degree of coal is often an important factor affecting the characteristics of coking coal. The volatile yield of coal in low rank coal is often affected by coal rock components. The volatile yield of EXINITE is the highest, inertinite is the lowest, and vitrinite is between the two.

In order to solve the problem of low accuracy in the current fault diagnosis method of large screw drilling rig, a fault diagnosis system of large screw drilling rig based on the combination of improved PSO (Particle Swarm Optimization Algorithm) and PNN (Probabilistic Neural Network) is proposed. Firstly, by reducing the inertia factor and learning factor, the particle velocity is indirectly adjusted from large to small, and the particle swarm optimization algorithm is improved. The benchmark function test shows that the convergence speed, accuracy and global optimization ability of the improved PSO are better than GA (Genetic Algorithm), WOA (Whale Optimization Algorithm), PSO and other conventional optimization algorithms. Then, the improved PSO is used to search the global optimal smoothing factor of PNN that can meet the prediction demand of the whole sample space, and loaded into PNN. The experimental results show that in terms of diagnosis accuracy and real-time performance, it is compared with the PNN with smoothing factor selected by empirical method and the PNN optimized by GA, WOA and PSO respectively. The fault diagnosis accuracy of PNN optimized by PSO is 97.5%. At the same time, the optimized PNN runs faster, and the analysis time of single group of fault data is 0.785 seconds, The above shows that the fault diagnosis system of large screw drill based on improved PSO-PNN can meet the requirements of large screw drill for fault diagnosis accuracy and real-time.

In order to solve the problem that the existing hydraulic support with four-link stable mechanism can not adjust its attitude autonomously under the support state, a new type of hydraulic support based on five-link stable mechanism is proposed. The five-link stable mechanism has two degrees of freedom, and the stable mechanism can operate freely under the working state of the hydraulic support, which effectively solves the problem that the four-link hydraulic support can not adjust its attitude autonomously under the normal support state. According to the specific structural characteristics of the five-link hydraulic support, this paper establishes the plane bar system model of the support, and deduces the relationship of the main mechanical parameters such as the support resistance of the hydraulic support, the force of the attitude adjusting jack, the upper front link force, the lower front link force and the rear link force. Based on the above relationship, combining with Creo software, the motion simulation is carried out. According to the simulation results, the effect and influence of hydraulic support link parameters on the link force, the force of the attitude adjusting jack and the support strength are analyzed, the specific optimization results are given, and the optimization direction of this type of support parameters is pointed out. The research results are of reference significance to the structural design of this type of support.

In order to solve the problems of high work intensity, high risk factor and low work efficiency when cleaning water bunkers in coal mines manually, a water bunker cleaning robot replaces manual cleaning of water bunkers, thus reducing the work intensity and risk of bunker cleaning workers. We develop a water bin cleaning robot system, which integrates coal mud excavation, dewatering and transportation, and realizes timely and efficient cleaning of coal mud in underground coal mine water bins. Detailed introduction of the system composition, principle and function. Analyze the cleaning effect of the water bin cleaning robot through the use of case studies. The application results show that the water bin cleaning robot system is suitable for coal mine underground water bin coal sludge cleaning work, which is of great significance to realize the intelligent construction of coal mine.