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Aiming at the engineering background of shallow coal seam burial depth, thick soil layer, thin bedrock and strong disturbance of fully mechanized caving mining in the loess gully area of northern Shanxi Province, two methods of comprehensive numerical calculation and field measurement are used to explore the failure characteristics of overlying rock during mining. The simulation results show that: under the condition of strong mining disturbance, the destructive influence of mining will be transmitted from depth to shallow. With the increase of the mining distance of the working face, the displacement and deformation of the mining stratum has a cumulative effect, and the destructive effect of mining has a development process of vertical rapid development, vertical stagnation and horizontal expansion, vertical rapid breakthrough, and the ratio of the water-conducting fracture zone to the mining thickness is about 19.7; the field measurement shows that the destructive impact of mining on the 10108 working face has broken through the critical plane between the bedrock and the soil layer, the mining cracks are connected up and down, and the overlying rock layer in the goaf no longer has the ability to block water. The failure characteristics of mining overburden are mainly high-angle longitudinal fractures. The damage height of mining overburden will not be less than 198.2 m, and the ratio of the water-conducting fracture zone to the mining thickness will not be less than 22. The comprehensive research results show that: fully mechanized caving mining of thick coal seam results in more severe damage of overlying strata, and high angle of mining-induced overlying strata can lead to the development of water fractures. Although the viscous laterite with strong plastic has a restraining effect on the longitudinal development of mining-induced fractures, it cannot naturally bridge and lose the barrier of shallow unconsolidated strata and surface water in a certain period after mining at the working face. The ratio of the water-conducting fracture zone to the mining thickness is 10.5% and 9.5% different from the numerical simulation results and the empirical formula respectively. Therefore, reasonable water prevention and control measures should be formulated in time.

In order to solve the problem of converting a large amount of original GNSS receiver observation data into RINEX format files independent of the receiver during satellite positioning measurement in railway line engineering plane control networks, this paper used the C # language for secondary development of the program. The GNSS receiver observation data of Trimble Company was taken as the research object, and the syntax rules of the batch processing file of the GNSS receiver original observation data which provided by the company decoding program Convert To RINEX were analyzed. Then, the batch processing file calling method of the program was used to develop the Trimble GNSS observation data batch processor. After engineering verification, this batch of processor software could conveniently and quickly convert the massive raw data of Trimble GNSS receivers into RINEX format files independent of the receivers, and can be applied to various large-scale satellite measurement projects such as railway line engineering plane control network satellite positioning measurement. [ABSTRACT FROM AUTHOR]

Taking the 2S103 intelligent fully mechanized mining face of Wangjiata Coal Mine as an example, the specific implementation plan and application effect of intelligent fully mechanized mining face are analyzed, and the existing technical problems are summarized. According to actual situation of 2S103 working face, the intelligent frequency conversion speed regulation scheme of scraper conveyor and transfer machine is studied. By adding speed comparison and judgment module of the transfer machine and the scraper conveyor, the problem of overload and shutdown of the transfer machine due to the lag in speed control is solved, at the same time, it also guarantees the linked speed regulation operation of the transfer machine; Taking engineering quality and manual input as measuring index, the optimal coal mining plan is determined which combines memory cutting, automatic machine following and support moving, and manual adjustment; The shearer,hydraulic support and integrated liquid supply system are modified to improve safety, practicability and maintenance efficiency of related equipment, and eliminate a large number of potential safety hazards. By comparing and analyzing from aspecets of electricity consumption per ton of coal, coal cutting efficiency, reverse osmosis water consumption, personnel input, and small and medium repair costs, it is concluded that the intelligent fully mechanized mining face has achieved certain effects in energy saving, staff reduction, and material reduction. Technical problems existing in the practical application of intelligent fully mechanized mining face are summarized, in case of special structure,coal mining technology needs to be improved, the analytic function of video monitoring system needs to be perfected, etc. It is pointed out that to realize the smart mine, the research on safety monitoring system and smart brain should be actively promoted, and put forward some construction ideas and directions.

Taking the 6-2116 fully mechanized coal mining face of No.2 shaft of Nalinmiao Coal Mine as the engineering background, in view of problems of large coal consumption and difficult coal transport in abandoned roadway backfilling on coal pillar recovery working faces, a hydraulic coal unloading device of belt conveyor in underground coal mine was designed. The device is composed of support device, redirection device and hydraulic system. It is installed at intersection of main transportation roadway and auxiliary retracement channel. Using hydraulic pump station as power, the coal is unloaded from the belt conveyor by the support device and the redirection device cooperatively,and then the coal is transported to the abandoned roadway. Through the coal unloading device, the raw coal does not need to be lifted into ground and then transported to underground by trackless rubber truck, which improves economic benefit and filling efficiency, and reduces safety risk. Field industrial test results show that when the shearing speed of shearer is 0.8 m/min, the speed of scraper conveyor is 0.4 m/s, the speed level of transfer machine is low, the speed of belt conveyor is 1.0 m/s, and the extension length of support cylinder and redirecting cylinder is 0.7 m, the coal unloading device can realize continuous coal unloading, which meets needs of coal backfilling for the test working face and ensures normal advancement of the coal pillar recovery working face.