Roadway Support Research Articles

Study on stress distribution law of surrounding rock of roadway under the goaf and mechanism of pressure relief and impact reduction

To safely extract residual coal from a mine affected by rock bursts, the concept of “roadways under goafs” has been proposed as an effective layout. The pressure relief and shock reduction mechanism of roadways under goafs is elucidated through theoretical analysis, numerical simulation, and engineering verification. The stress model for goafs is established based on elastoplastic mechanics, followed by the construction of a force model for coal beneath the goafs. The stress composition of roof, floor and two sides of roadway under a goaf are analyzed. Using the FLAC-PFC coupling simulation method, the excavation process from top coal mining to bottom coal mining roadways of a No. 17 coal mine in Heilongjiang Province was simulated. The simulation results validate the spatiotemporal evolution of the stress and displacement in the surrounding rock mass of the roadway situated beneath goafs and determine the precise location of the roadway and length of its bottom coal face. A large diameter borehole of the roadway and presplitting blasting of the coal face roof are used to solve the local high stress danger area. Moreover, the roadway support mode of the “steel shed + spray arch support + monomer + π steel beam” is proposed. Finally, through the data of the field micro-seismic and stress monitoring system, the effectiveness of the pressure relief and shock reduction of roadways under goafs, the high efficiency of local danger relief of the roadways and working faces, and the practicability of the “steel shed + spray arch support + monomer + π steel beam” support of the roadways broken by surrounding rock are verified. A good basis for choosing a reasonable location for roadways and surrounding rock control methods for residual bottom coal mining and rock burst mining can be found in the research results.

The evolution law of deviatoric stress and asymmetric control technology in roadways during panel mining through overlying residual coal pillars

Close-distance coal seams (CDCS) are widely distributed, and the layout of the upper and lower panels can be divided into “=” type and “+” type. The “+” superposition of upper and lower coal pillars in CDCS caused strong mine pressure, but there are few studies on the panel crossing residual coal pillars (RCP) when the upper and lower coal seams are “+” type layout. In view of the special spatial position (“+” type layout), this paper takes the typical panel 4-301 of a particular mine as the project indagation background and studies mining and crossing the overlying coal pillars by dint of field measurement, numerical simulation, indoor test, and engineering application. Compared with vertical stress or horizontal stress alone, the indexes of deviatoric stress and plastic zone can reflect the failure evolution of surrounding rock more comprehensively. Hence, this paper analyzes the expansion form of the plastic zone and the variation law of deviatoric stress before and after mining influence in the underlying mining roadway. The research results show that: (1) There is a sub-peak zone of deviatoric stress under the RCP. The deviatoric stress is bimodal in the range of 9 m below. After the peak value decays to 7.4 MPa, it changes to a single peak located in the area directly below the middle of the RCP. (2) The maximum plastic zones of the roof and two ribs of the roadway below the RCP are 3.4 m and 5 m, respectively. The crest value of deviatoric stress reaches 10 MPa. As the distance between the panel and the RCP decreases, the shape of the high deviatoric stress area presents the evolution law from the “ellipse” of the roof → the “crescent” of two ribs → the “cochlea” of the tips of the ribs. (3) When the mining of the underlying panel is 10 m, 0 m, or − 10 m away from the RCP (without passing through the RCP). The crest value of deviatoric stress within 5–10 m in advance of the roadway increases in turn. However, the peak value is significantly reduced when it is − 20 m away from the RCP (through the RCP). The crest value of deviatoric stress of two ribs decreases in turn along the panel rib → section coal pillar rib → solid coal rib. Based on this, the underlying 45 m of the RCP is divided into area I (10 m), area II (overlapping area 20 m), and area III (15 m) based on the degree of disturbance. And propose the technical scheme of asymmetric combined control in different zones by using asymmetric channel steel truss anchor cable for the top-ribs of areas I and III, and top-ribs asymmetric channel steel truss anchor cable + door-type support in area II. On-site project practice shows that the partitioned control technology successfully resisted the roadway instability and failure caused by the dynamic-static superimposed stress disturbance under the RCP and realized the primary support of the sectional coal roadway. The conclusion provides technical support and scheme design for the partitioning support of roadways under similar “+” type cross‐panels.

Research on the Failure Mechanism of Surrounding Rock in a Dynamic Pressure Roadway and Active and Passive Coordinated Support Technology

To study the phenomenon of large deformation and the failure of roadways under dynamic pressure, this paper takes the 10607 gas drainage roadway as the research object and presents the results of a theoretical derivation of equations for the boundary of the plastic zone of a dynamic pressure roadway with and without supporting force. The impacts of the mining influence coefficient and supporting force on the plastic zone boundary were explored for various lateral pressure coefficients. As the supporting force was increased, it was observed that there was a slight reduction in the radius of the plastic zone of the dynamic pressure roadway, while its scope and shape barely changed. Based on the failure mechanism of the dynamic pressure roadway, active and passive support technology was proposed, and the support effect was analyzed using FLAC3D 5.0 numerical simulation software for the case of the 10607 gas drainage roadway.

Research and development of fully enclosed wire-shell support structure technology for deep soft rock roadway based on TRIZ theory

The TRIZ theory was used to accurately discover the problems to be solved in the design of roadway surrounding rock control technology. This paper tried to solve the complex issue of surrounding rock control in deep roadways from a new perspective. Based on the functional component analysis and causal axis analysis of the problem’s primary reason, simultaneously, the surrounding rock control technology was optimized through technical contradiction analysis, physical contradiction analysis, and substance and field model analysis. As a result, a fully enclosed wire-shell support technology was proposed. Finally, taking the typical soft rock roadway engineering of Pansan Coal Mine in Huainan Mining Area, Anhui Province, China, as the engineering background, the engineering application and effect evaluation were completed. This paper provides a reference for controlling the instability of deep soft rock roadways in coal mines. A new idea of optimizing roadway support engineering based on TRIZ theory was proposed.

Large Section of Soft Rock Gob-Side Entry Retaining Surrounding Rock Control

When cutting roof and pressure relief, the impact of blasting is especially obvious on the integrity of the roof of a large-section soft-rock roadway. The reasonable parameters of blasting roof cutting were studied through using Xiaohezui coal mine -12110 roadway as the engineering background. The LS-Dyna simulation results show that: Interval blasting is beneficial to the expansion of interhole cracks and the damage to the perimeter of the hole is smaller than that of adjacent blasting, the lower the charge uncoupling factor, the larger the perimeter of the hole fragmentation zone. The mechanical model of the large-section soft-rock roadway after retrieval was established, the support resistance equation of the roadway side support and the gangue in the extraction area was derived, and the minimum support force required for the roadway side support was solved. According to the site situation, the roadway support scheme for different areas was proposed, and after continuous delamination monitoring of the roof plate, it was found that the amount of roof-plate delamination was finally stabilized within 180 mm after the working face was advanced, and the effect of leaving the roadway was good.

Instability mechanism and control technology of soft rock roadways affected by mining in karst mountain area

The deformation and damage of soft rock roadways in karst mountainous area is serious, which greatly restricts the safe and efficient mining of coal resources. To explore the instability mechanism of soft rock roadway under the influence of mining, the 226 rail cross-cut of Shanjiaoshu Coal Mine in China was taken as an engineering background. The methods of field monitoring and drilling imaging were adopted to analyze the roadway failure characteristics. In addition, the distributions of the plastic zone, surface displacement, and fracture fractal evolution characteristics of the surrounding rock for different stress wave peak and stress wave frequency are compared and analyzed using UDEC software. Then, the combined support scheme of “secondary strong bolting and grouting” is proposed to control the severe deformation of the roadway. The primary support mainly adopts short hollow grouting anchor cable to strengthen the shallow broken surrounding rock within 0–3 m. The secondary reinforced support adopts long hollow grouting anchor cable or constant resistance large deformation anchor cable to fully mobilize the bearing capacity of deep surrounding rock and to ensure the long-term stability of the roadway. On-site monitoring showed that the scheme could effectively control the severe deformation of the roadway, which also provided a reference for other similar roadway support.

Mine wind speed sensor location selection based on decision tree theory

Abstract In order to realize the scientific layout of underground roadway sensors, based on the information entropy theory, the decision tree algorithm is applied to the location selection of the underground wind speed sensor. Taking the air volume traversing the entire network branch as the goal, the node air volume balance and the characteristic relationship between air volume and wind pressure as the constraints, the conventional layout data of the mine wind speed sensor is selected as the training sample, and the reasonable decision node is selected by measuring the uncertainty of the characteristic attribute. The research shows that the smaller the information entropy of the layout elements, the greater the weight in determining the sensor location. The classification conditions obtained by the wind speed sensor are, in descending, order: airflow disturbance, roadway support, distance from the inlet (return) and outlet, and roadway type. Algorithms are applied to effectively combine downhole sensor siting with historical data containing unambiguous results.

Study on failure mechanism and control of surrounding rock of inclined strata crossing roadway in deep coal mine

China’s coal mines are mainly underground mines, and a large number of roadways have to be excavated underground. It is of great significance for coal mine production to adopt safe and reasonable roadway support methods. In the process of roadway excavation, the rock stratum is inclined and the roadway pass through the layer. Since the surrounding rock conditions of the roadway passing through the layer are more complicated, it is easy to cause deformation of surrounding rock, failure and floor heave, which makes the support work difficult. In order to solve this problem, the mechanical properties of roadway surrounding rock were tested and the failure of roadway surrounding rock was analyzed using the +260 horizontal centralized transportation roadway in Changcheng No.2 mine. The surrounding rock of the roadway was divided into 8 regions, and the stress analysis of the surrounding rock in different regions was carried out. It is found that the left shoulder pit, the right side and the floor of the roadway are prone to damage. The influence of the lateral pressure coefficient, the rock dip angle and the lithology on the failure of the roadway surrounding rock was analyzed by Mohr-Coulomb failure criterion, and the specific failure range of the roadway surrounding rock was obtained. The support optimization design of the roadway was carried out, and the weak area of the surrounding rock was reinforced. The deformation monitoring of roadway surrounding rock after support optimization was carried out. The field monitoring results show that after the optimized support, the displacement of the roof and floor of the roadway section and the two sides are reduced by 43.6% and 40.8% respectively compared with the original scheme, and the deformation of the surrounding rock also shows a trend of gradual stability, and the surrounding rock of the roadway is effectively controlled. The research can provide a new way for the stress and failure analysis of the surrounding rock of the inclined rock roadway.

Application research on composite support technology of concrete-filled steel tube support in high stress and large deformation soft rock roadway: A case study

Aiming at the surrounding rock control problem of high stress and large deformation soft rock roadway. This article takes the 141712 coal haulage uphill as the engineering background in Guizhou Panjiang Mining Area. Through field investigation, theoretical calculation, numerical simulation, and industrial tests, the deformation characteristics of surrounding rock and the mechanism of roadway instability and failure were revealed. And a composite support scheme of "bolt (cable) + grouting + concrete-filled steel tube support" was designed. A strengthening support mechanical model of “Three-arch” based on the concrete-filled steel tube support technology was established. The ultimate bearing capacity of the design scheme above is calculated, which meets the support load and can maintain the stability of the soft rock roadway. Through numerical simulation analysis, the distribution characteristics of the plastic zone, stress field and displacement field of the design scheme are obtained, and the rationality of the scheme is verified. The industrial tests were successfully applied and the field monitoring results show that the deformation is within the controllable range, effectively controls the deformation of the 141712 roadway. The research results can provide a reference case for the control of soft rock roadway with high stress and large deformation under similar complex conditions.

Failure mechanism and strengthening countermeasures of end-anchored cable free section under combined tension and shear

As an effective and economical reinforcement method, end anchorage cables are widely used for roadway support in coal mines. The failure of the free section of the end-anchored cable (FSEC) under the combined action of tension and shear is a key factor inducing roof collapse accidents in coal mine roadways. Based on cable bolt tensile and shear test results, this paper aims to reveal the failure mechanism of the FSEC under tension and shear by establishing a mechanical model of the interaction between the cable bolt and jointed rock mass. The results show that the axial and shear force coupling in the FSEC increases because of the joint plane shear action. The FSEC is subject to tensile–shear failure when the axial and shear forces meet the tensile–shear composite yield condition at the inflection point of the sheared cable bolt. The steel strands of the cable bolt experience and transmit shear force through the contact point, resulting in an uneven distribution of shear stress in the cable bolt cross-section, directly causing the FSEC’s local failure. Strengthening countermeasures are proposed using a high-strength slotted steel pipe to protect the cable bolt under shear, and a strengthening device has also been designed. Experimental results obtained in the laboratory have revealed that the strengthening device does not only effectively enhance the cable bolt’s shear capacity by increasing its shear strength and changing the shear transfer mode, but also significantly improves the cable bolt’s comprehensive performance. This study elucidated the failure mechanism of the FSEC and provides a practical and convenient method for increasing the shear strength of an end-anchorage cable system and enhancing roadway stability.

Research on Damage Evolution Law of Glazed Hollow Beads-Cement/Sodium Silicate Grouting Materials under Different Cycles of Loading and Unloading.

With the depletion of shallow resources, deep resource mining has become a trend. However, the high temperature and complex stress environment in deep mines make resource extraction extremely challenging. This paper developed a thermal insulation grouting material made of glazed hollow beads, sodium silicate, and cement and tested the compressive strength, gelation time, and stone rate under various curing days in light of the issue of high temperature heat damage in high ground temperature mines and the impact of mining on roadway grouting bolt support. Fatigue strength, fatigue deformation, load-residual strain, energy evolution and microscopic features were studied and analyzed in relation to the damage law of graded cyclic loading and unloading under the number of varying cycles. The findings demonstrate that cyclic loading and unloading strength is lower than uniaxial compressive strength. The fatigue strength is significantly decreased when the number of cycles reaches its limit. Residual strain is less sensitive to changes in stress than load strain. The fitting correlation coefficients of total output energy and elastic energy are higher than 0.71.

Deformation processes in roadway support systems at deep shaft in Skalisty Mine

Deformation processes in roadway support systems at deep shaft in Skalisty Mine

Environmentally friendly concrete material with early strength and fast hardening using coal as an aggregate: a case for supporting empty roadways

In order to facilitate ventilation or transportation, many coal mines usually excavate an empty roadway in the middle of the mining working face. Under the influence of mining pressure, empty roadways are easily damaged, seriously threatening coal mines’ safety. Because the traditional support method of the empty roadway has the problems of low efficiency, high cost, and low strength, this paper researches the coal-based concrete support material with better effect. The grading test of coal aggregate was carried out, and it was found that the percentage of small-size aggregate greatly influenced the reduction of aggregate porosity in the stacked state. To solve the problems of the high cost of strengthening support methods such as high water material support in empty roadways, which could be more conducive to recovery and reduce coal quality. The research on empty roadways supports concrete material with coal as aggregate, making the working face recover coal resources safely and efficiently. The optimum gradation test of the total is to enhance the strength of support and solve the problem of low power and difficult cementation of coal. Based on the hydration analysis of cementitious material, the coal-based concrete, mainly composed of low-cost slag, is determined. The cementitious material with simple composition, rapid setting, and fast hardening was found. It is proved that the mechanical properties and molding effect of coal-based concrete support composed of gypsum, GGBFS, and clinkercement are better than those of commercial cement. The structural model of “surrounding rock-empty roadways-coal pillar-support” is established. The calculation method and check basis of empty roadways support resistance N1 are obtained. The results of industrial application verified that coal-based concrete could effectively protect empty roadways without affecting the productivity of coal mines.

Monitoring Technology of Surrounding Rock Deformation Based on IWFBG Sensing Principle and Its Application

Abstract To address the challenge of achieving precise real-time monitoring of significant deformation in deep roadway surrounding rock, a quasi-distributed strain-sensing cable (SSC), which has a spatial resolution of 1 m, was developed based on the principle of Identical Weak Fiber Bragg Gratings. The performance of SSC has been evaluated through a series of calibration tests, revealing a range of 0%–3%, an accuracy level of 0.5%, a strain sensitivity measuring at 1.23 pm/με, and a temperature sensitivity recorded as 10.78 pm/℃. Furthermore, a real-time deformation monitoring system has been established to monitor rock deformation, consisting of SSC, supporting installation equipment, demodulation equipment, and monitoring software. Moreover, the proposed methodology was applied in the deep roadway of Guqiao coal mine. The results showed that the maximum surface displacement of the roadway is 103.47 mm, while the lateral contrast error stands at 5%. The maximum strain value of the surrounding rock measures 27,095 με. The depth of rock rupture zone is about 3 m, while the boundary of rock damage zone extends up to 6 m. This information serves as the foundation for determining the parameters of the roadway reinforcement support design.

A method for determining the optimum supporting opportunity of roadway based on energy dissipation

The time and space of the support structure applying is related to the overall stability of the roadway after excavation directly. Designed twenty-four groups of roadway support schemes with time and space dimensions, and studied the stability characteristics of roadway in different schemes by using Fast Lagrangian Analysis of Continua in Three Dimensions. The main conclusions are as follows: the influence of energy dissipation (time) and support position (space) on the stability of the roadway is not a linear relationship, and supporting at the appropriate opportunity can be beneficial. Established the "displacement-dissipation energy" curve, founding that there is an obvious "jump" phenomenon in the dissipation energy of surrounding rock during the process of gradually increasing displacement. A novel method for determining the optimum supporting opportunity of roadway based on energy dissipation was proposed, based on the above finding. This study can provide an original idea for the determination of roadway supporting opportunity.

A new grouting cable without a core tube used for reinforcement of fractured rock mass

Grouting cable is a newly developed technology for the reinforcement of fractured rock mass in coal mines of China. It integrates the procedures of cable anchoring and grouting, thus simplifying the working procedure of roadway support. However, ordinary grouting cable products with a core tube have some significant defects, such as a narrow flow channel, difficulty in slurry diffusion and significant reduction of cable strength. To overcome these shortcomings of ordinary grouting cables, this paper proposes a new kind of grouting cable without a core tube. The ordinary plastic core tube is replaced by a steel core wrapped by several steel strands. The inner gap between the steel strands and steel core is used as the slurry flow channel. The optimised measures can significantly improve slurry diffusion and strength performance of the grouting cable. As a novel idea, several samples of the new grouting cable were produced. Lab testing and field application experiment indicated that slurry diffusion and strength performance of the new grouting cable had been significantly improved compared with ordinary ones.

Study on the deformation failure mechanism and coupling support technology of soft rock roadways in strong wind oxidation zones

Due to the influence of sedimentary environment, the coal seams and overlying rocks in the wind oxidation zone exhibit developed fractures, high rock porosity, strength attenuation, and poor self-stability. It leads to the large deformation of the surrounding rock and managing the roof of roadways difficultly. This made the roadway excavation extremely difficult. And the rendering conventional “bolt-cable-mesh (belt)-shotcrete” combined support system was not applicable. In this paper, the No. 49,104 air return roadway in the strong wind oxidation zone of the Shuiquan Coal Mine was selected as the engineering background. The change trends of the coal and rock in the strong wind oxidation zone physical and mechanical properties were revealed, and the deformation and failure mechanism was analyzed. According to the deformation and failure characteristics of the roadway in the wind oxidation surrounding rock with engineering practice, a coupling support scheme “pregrouting + anchor net and sprayed concrete + inverted arch structure + U-shaped steel + high and low-pressure, deep and shallow-hole reinforcement grouting” was proposed. A roadway grouting reinforcement diffusion range model was established in COMSOL Multiphysics, and the grouting diffusion range was then imported into FLAC3D to compare and analyze the coupling support scheme reinforcement effect of roadway in the strong wind oxidation zone. And the coupling support scheme was used to reinforce the No. 49,104 air return roadway, and the reinforcement effect was monitored in situ. Results showed that the proposed coupling support and reinforcement scheme can be employed to effectively control the deformation of the surrounding rock and the expansion of plastic zone damage. And the stability and safety of the roadway were significantly improved. This coupling support scheme was reasonably designed, and it could provide an engineering reference for the support and reinforcement of roadways in weak and crushed surrounding rocks under similar geological conditions.

Study on instability mechanism of soft rock roadway and pressure-relief bolt-grouting support technology

Aiming at the engineering problem of roadway deformation and instability of swelling soft rock widely existed in Kailuan mining area, the mineral composition and microstructure of such soft rock were obtained by conducting scanning electron microscopy, X-ray diffraction experiments, uniaxial and conventional triaxial tests, and the law of softening and expanding of such soft rock and the failure mechanism of surrounding rock were identified. The combined support scheme of multi-level anchor bolt, bottom corner pressure relief and fractional grouting is proposed. The roadway supporting parameters are adjusted and optimized by FLAC3D numerical simulation, and three supporting methods of multi-layer anchor bolt, bottom corner pressure relief and fractional grouting are determined and their parameters are optimized. The study results show that: the total amount of clay minerals is 53–75%, pores, fissures, nanoscale and micron layer gaps are developed, providing a penetrating channel for water infiltration to soften the surrounding rock; the three-level anchor pressure-relief and grouting support technology can control the sinking amount of the roof within 170 mm, the bottom drum amount within 210 mm, the bolts of each level is evenly distributed in tension, and the maximum stress and bottom drum displacement in the pressure relief area are significantly reduced; the pressure-relief groove promotes the development of bottom corner cracks, accelerates the secondary distribution of peripheral stress, and weakens the effect of high stress on the shallow area. Using time or displacement as the index, optimizing the grouting time, filling the primary and excavation cracks, blocking the expansion and softening effect of water on the rock mass, realizing the dynamic unity of structural yielding pressure and surrounding rock modification, has guiding significance for the support control of soft rock roadway.

The Active Roof Supporting Technique of a Double-Layer Flexible and Thick Anchorage for Deep Withdrawal Roadway under Strong Mining Disturbance

Due to the strong disturbance of a mining face, the surrounding rock of the withdrawal roadway is susceptible to deformation and failure, which restricts the safe and efficient evacuation of mining equipment. To resolve this longstanding technical problem in mine production, an engineering investigation, numerical simulation, theoretical analysis, and other research methodologies were conducted in this study. Furthermore, the influence mechanism of mining-induced stress on the withdrawal roadway was revealed, the anti-disturbance principles of thick-layer anchorage of roadway roofs were elucidated, and a novel double-layer flexible support technique was proposed. The front abutment pressure, stress superposition, damage accumulation of the surrounding rock, and the fluctuation of mining-induced stress are the primary factors contributing to the significant deformation of the surrounding rock in a withdrawal roadway. However, the fluctuation of mining-induced stress has usually been ignored in previous studies, and it may be the most crucial cause of the significant deformation and instability of the surrounding rock. The thickness of the anchored rock beam is the most vital factor affecting the maximum subsidence and maximum tensile stress of the roof, and increasing the thickness of the anchored rock beam can significantly improve the stability and anti-disturbance performance of the roof. In the proposed double-layer flexible supporting technique, flexible steel strands serve as the carrier, which overcomes the constraint of the roadway height on the length of roof support components. The first layer of flexible support is used to construct a thick fundamental anchorage layer, while the second layer is employed to construct a thicker reinforced anchorage layer, facilitating the effective resistance of the roof against strong mining disturbances. The effectiveness of this technique was further validated through the application of an engineering practice. The research results have reference value for solving the difficult problem of mining roadway support.

Mine pressure behavior law of isolated island working face under extremely close goaf in shallow coal seam

In order to study the mining pressure characteristics of the shallow buried coal seam with the same silo working face under the very close mining void zone and the overlying coal rock body, the theoretical analysis is used to determine whether the open-cutting eye bearing layer belongs to the mining under the very close mining void zone or not, based on the numerical simulation of FLAC3D and on-site measurement of the working resistance at the end of the cycle of the working face's hydraulic bracket, It is proposed to divide the mining stress of the working face based on the advancing length of the working face, that is, the high-pressure zone, the transition zone and the low-pressure zone. The results of the study show that: FLAC3D software was used to analyze the stress intensity of the “C” island working face when it was mined back to 50 m, 100 m, 150 m, and 180 m (one time “square”), and the simulation results were imported into the Origin software, which was used to analyze the stress intensity of the working face. The simulation results were imported into Origin software, and the influence range of mining stress was divided into four areas: high-stress area, stress transition area, low-stress area, and "square" stress concentration area. According to the on-site measurement of the working resistance at the end of hydraulic support cycle, the initial pressure step of the working face under the overlying coal rock body is 48.9–55.7 m, with the peak value of 38 MPa, the cycle pressure step is 9.0–23.3 m, with the peak value of 36 MPa, and the dynamic load factor of the working face is 1.14–1.16; relative to the overlying coal rock body, the average decrease of the cycle pressure step is nearly 10% and the average increase of dynamic load factor is 1.14–1.16; compared with that under the overlying coal rock body, the average decrease of the cycle pressure step is nearly 10% and the average increase of dynamic load factor is 1.14–1.16. Compared with the overlying coal rock body, the average decrease of the cycle pressure step under the overlying mining zone is nearly 10%, the average increase of the dynamic load factor is 20%, and there is no obvious regularity and periodicity in the direction of strike, and the working face is divided into three parts along the direction of strike: high-pressure zone, transition zone, and low-pressure zone. Therefore, in the process of mining under the overlying coal rock body, we should strengthen the roadway peripheral rock support and roof and floor management, which is of guiding significance to the mining of similar working faces and mine safety production.