To investigate the mechanical stability and energy evolution of roof-cemented backfilling-floor composite structures (RCFs), this study employs AE monitoring and FDEM numerical simulation to analyze the damage and energy characteristics of RCFs under varying the dip angle of rock-backfill interfaces (DA), roof-to-floor height ratio (RFR), and equivalent height of backfilling (EHB). Key results show that dissipated energy density sharply increases at 0.7–0.9 times peak stress, a critical threshold for RCFs transitioning from elastic energy storage to plastic dissipation. After entering the elastic strain stage, the damage variable grows exponentially with strain: increasing DA and EHB retards damage and enhances plasticity, while RFR induces a typical “M”-shaped variation. FDEM simulations reveal nearly all input energy (Et) converts to strain energy (Es) pre-peak, with kinetic energy (Ek) increasing progressively post-peak. Experimental strain energy (U) at peak stress is consistently lower than simulated Es, as the model fails to fully account for inherent micro-defects and interface meso-heterogeneity. Microcracks are concentrated at 50°130°, predominantly oblique shear, tensile-shear, and tensile cracks, with the cemented backfilling as the core crack initiation and propagation zone. This study provides theoretical and technical support for roadway layout optimization and stability evaluation of backfilled areas in related mining practices.

The mid-Neoproterozoic tectonic evolution of the western Jiangnan Orogen in the context of the Rodinia supercontinent remains unresolved due to debates regarding the interpretation of the petrogenesis of igneous rocks. In this study, we present an integrated dataset of petrology, whole-rock geochemistry, zircon U-Pb ages, and Hf isotopes for granitic samples from the Fanjingshan area in the western Jiangnan Orogen. LA-ICP-MS zircon U-Pb dating indicates that they crystallised ca. 810 Ma. Whole-rock geochemical data demonstrate that they exhibit typical features of S-type granites and were derived from dehydration melting of a metasedimentary protolith. Zircon epsilon Hf(t) values range from -7.9 to 1.6, with a main peak value of -3.5. Two-stage Hf model ages of 1.5-1.9 Ga suggest that these granites were derived from ancient crustal materials. Extensive fractional crystallisation and magmatic-hydrothermal interactions are inferred from low rare earth element (REE) contents, low Nb/Ta and Zr/Hf ratios, and a distinct REE tetrad effect. Combined with coeval arc-related magmatism and rift basins, the Fanjingshan granites were most likely emplaced in a back-arc setting. Available data indicate that rift basins occurred extensively at the periphery of the Yangtze Block ca. 810 Ga, implying their involvement in the breakup of the Rodinia supercontinent.

Mining-induced catastrophic landslides in Southwest China pose severe threats to the ecological environment and human life. Taking the Nayong Landslide in Guizhou Province as a representative case study, this study systematically investigates the deformation and failure characteristics of the slope induced by mining. The evolutionary process of mining-induced landslide was examined, and a mechanical model of the overlying strata structure was established. Based on this model, mechanical criteria governing key block sliding instability and rotational deformation instability were derived. The results indicate the formation of collapse zones and ground fissures along the slope surface and trailing edge during the coal seam mining beneath the slope. Dense tensile cracks appeared at the trailing edge of the slope, while deeply developed shear cracks formed at the slope’s front edge. Consequently, dangerous rock masses collapsed, initiating a landslide. The mining-induced landslide evolved through four stages: fracture and subsidence of the overlying strata in the goaf, slope deformation and damage, overall slope instability, and sliding of the collapse-slide mass. The deformation and instability mechanism was characterised as a ‘shear instability–fragmented sliding collapse’ process. The study findings provide a theoretical foundation for the prevention of catastrophic landslide disasters induced by coal mining.

Support technology faces challenges in view of the large deformation of surrounding rock in three-soft coal roadways under high horizontal stress in Zijin Coal Mine, China. Geostress near the tested working face of the mine was measured and its distribution law was analyzed through theoretical analysis, numerical simulation analysis, and field measurement. The original supporting scheme of the three-soft coal roadway on the tested working face was analyzed to discover the deformation and failure mechanism of the surrounding rock of the original supporting roadway and the control measures. An optimized support scheme of H-G (hollow grouting) anchor cables, high strength bolts, W-shaped steel belts, metal meshes, and sprayed concretes was proposed for field applications. Based on the roadway in the tested 3201 working face at Zijin Coal Mine, the technical parameters for optimizing the combined support of the roadway were determined. The following results were be obtained through field measurement. The roadway was kept intact after excavation and the optimized support scheme was adopted in the three-soft coal roadway. No obvious deformation in appearance existed in the roof, floor, and roadway coal sides. Compared with the original support scheme, the stability of the roadways was improved visibly. The displacement of the roadway roof decreased from 100 to 30 mm, and that of the roadway coal walls decreased from more than 100 mm to less than 50 mm. This work verifies the effectiveness of a combined support scheme of H-G anchor cables, high strength bolts, W-shaped steel belts, metal meshes, and sprayed concretes to control deformations of surrounding rock in three-soft coal roadways. The new support scheme has good social and economic benefits and can be used as a reference for other roadway supports under similar conditions.

The concept of output orientation（OBE） is the educational output, that is, students’ ability to achieve as the goal oriented, student-centered, using reverse thinking way to systematically construct the curriculum system of education concept. Taking the course of Coal Mine Geology as an example, this paper, based on the concept of output orientation（OBE）, optimizes the course assessment and determines the scoring standards of different assessment links, centering on the problems of single traditional course assessment method, solidified form and content of examination paper, mismatch between assessment links and teaching methods, insufficient basis for continuous improvement and so on. To achieve accurate evaluation of the degree of achievement of curriculum teaching objectives.

Stress in rock masses is an important parameter in the design and construction of underground engineering, such as the design and maintenance of mine roadways and the design of mining working faces. It is also a fundamental force causing the deformation and failure of geotechnical engineering excavation. At present, the abutment-pressure monitoring technology of the surrounding rocks of the coal mine roadway in China is not intelligent and systematic and lacks some high-precision sensing instruments and multi-functional monitoring systems. The mechanical model of the rocks surrounding the borehole was constructed by theoretical analysis of problems in the stress monitoring technology for underground rock masses in coal mines. Additionally, the interaction between the surrounding rocks and the borehole stress meter was analyzed. The borehole stress meters for tubular-structure fiber Bragg grating (TS-FBG) and cystic-structure fiber Bragg grating (CS-FBG) were designed by combining the sensing principle and sensing characteristics of fiber Bragg grating, and the performance of the two kinds of fiber Bragg grating borehole stress meters was compared by laboratory test. The track roadway of the 14,301 tested working faces in the Shaqu Coal Mine was taken as an example, and the stress of the rocks surrounding the 14,301-track roadway was monitored in real time by CS-FBG borehole stress meter during the mining of the working face. The following conclusions are drawn from the field application. The rig-site utilization results revealed obvious stress growth and stress peak zones in the mining-stress change curves of each measuring point on the two sides of the 14,301-track roadway in the process of mining the tested working face. Additionally, there were four stages: rapid rise, uniform growth, rapid rise to the peak, and rapid decline. Maximum stress monitored by the second station was 18.5 MPa, and the influence range of stress was over 140 m. Maximum stress monitored by the first measuring station was 19 MPa, the influence range of stress was about 80 m, and the peak stress position was about 20 m in front of the coal wall. Rig-site utilization proved the design of the CS-FBG borehole stress meter to be reasonable. Performance was stable and reliable, and the successful operation of field monitoring achieved the expected effect.

随着信息技术的不断发展,矿业开始进入了转型阶段,重视使用智能化技术,落实绿色安全生产理念,在这一背景下,矿业对于优质人才的需求量有所增加,相关高校重视对教学模式进行改革,加快专业学科建设,提升学生的创新创业能力,满足社会发展以及行业转型对于优质人才的需求.采矿工程专业教学改革难度较大,传统教学方法过于单一,偏向于理论化,而虚拟仿真实验教学体系的建设可以为学生提供形象化的教学环境,以具象的方式展示理论知识,有利于推进教学改革.基于此,对虚拟仿真实验教学体系的建设意义和策略进行了分析,以期为教学改革提供参考意见.

新工科建设为采矿工程等传统工科的升级改造指明了发展方向,提供了充足的专业建设平台与空间.随着智能装备在矿业领域的快速研发、生产和应用,智能采矿建设产生了"循演论"与"跃进说"的分歧,并由此产生了智能采矿专业与采矿装备两者之间的"本末之争".当前部分高校在智能采矿专业的国际化方面存在"过激"行为,就太空采矿对智能采矿提出的新要求认识不足.高校的智能采矿新工科专业建设要以采矿为本,循序渐进,积极应对国际化与太空采矿所带来的机遇与挑战.

作为一种先进的教育理念,产出导向(OBE)已被世界认可,进行了数十年的研究和实践.但如何在课程教学设计中落实OBE理念,仍是工程教育改革的重点.本文研究了OBE理念下课程教学设计的三个关键环节,即明确设计原则、分析框架与要点、重构教学大纲,探讨了各环节的操作要点,提出了教学目标、毕业要求指标点、教学内容及方法、课程考核评价等要素的内在逻辑关系,并以采矿工程专业《煤矿地质学》课程为例加以阐释,希望与同仁探讨,并提供有益参考.

Four representative TS-RCR (three-soft rock-coal-rock) structural bodies were selected according to the lithofacies analysis of coal measures in the Xiangshui Coal Mine, Guizhou, China, to analyze the mechanical properties, internal structure damage characteristics, and crack evolution law of the TS-RCR structural body composed of a soft roof, a soft floor, and soft coal seams. The mechanical model of the TS-RCR structural body was proposed. (1) The stress-strain curves of TS-RCR structures with different lithologies under cyclic loading and unloading show a change rule of sparsity, density, and sparsity with the increased cycles. The deformation of TS-RCR structures under cyclic loading and unloading can be divided into four stages. When the height ratio of the TS-RCR structural body was the same, the higher the strength of the upper and lower rocks, the more cycles the TS-RCR structural body had, and the denser the cyclic loading and unloading curve. On the contrary, the fewer cycles the TS-RCR structural body had, the sparser the cyclic loading and unloading curve. (2) The T 2 (transverse relaxation time) spectrum curves of the structural bodies were monitored at about 1 and 10 ms, and two obvious peaks were detected, indicating micropores and mesopores with a large volume in the structural body. Signal intensity increased at the relaxation time of 1 ms, decreased at 10–100 ms, and increased slightly at 100–1000 ms. The pore structure of the structural body with different lithologies changed significantly with the increased cycle number. (3) The damage and failure process of the structural body was roughly divided into three periods according to the time-history analysis of acoustic-emission AF (the ratio of acoustic-emission ringing count to duration) of the structural body: the active period with a relatively low AF value (AF < 60 kHz) in the 1 st -2 nd cycles; the rising period with a relatively stable increase of the AF value in the 3 rd -4 th cycles; and the explosive period with a relatively high AF value (AF ≥ 60 kHz) in the 5 th cycles. According to the relationship between the RA (the ratio of the rise time to the amplitude of the acoustic-emission-detection wave) value and time, the evolution law of the RA value and AF value of structures with different lithologies is similar in different periods under cyclic loading and unloading.

运筹学课程为采矿工程专业的一门必修课,旨在培养学生的分析思维能力和运算能力,提升学生的优化意识.文章以运筹学课程的期末试卷成绩和目标达成度为基础,分析考试成绩和达成度的整体情况,并在试卷、教学和科研等方面提出建议.

Triaxial seepage tests were conducted on the consolidated collapse column specimens to investigate their mechanical properties under seepage-stress coupling effects using a triaxial multifield coupled mechanical test system for rocks. The effects of initial consolidation pressures and specimen components on mechanical properties and seepage characteristics of consolidated collapse column specimens were analyzed. Test results showed the following: (1) The stress–strain curves of consolidated collapse column specimens could be classified in three stages, namely, compaction stage, linear deformation stage, and creep-like deformation stage, while the permeability during loading showed an obvious four-stage evolution of gradual decrease, stable development, rapid increase, and slow decrease. (2) Under same sample components, the permeability characteristics of consolidated collapse column specimens showed an obvious initial consolidation pressure effect. The initial consolidation pressure changed the distribution of pores and fractures in the specimens, leading to a decreased peak permeability as the initial consolidation pressure increased. (3) At the initial stage of loading, the permeability of consolidated specimens was mainly affected by the initial consolidation pressure, and the corresponding permeability decreased with the increase of the consolidation pressure. When the consolidated specimens were gradually compacted, the main factor influencing the permeability changed to the specimen components. The peak permeability of consolidated specimens comprising grey mudstone and conglomerate was the largest, while the fuchsia mudstone would reduce the specimen permeability, and the peak permeability decreased with the fuchsia mudstone components.

There are more and more tunnel projects in the karst-developed areas in Southwest China. Affected by karst caves and water, karst tunnels often experience geological disasters such as local collapses and water inrush. A simplified rock stress hardening-softening model was established based on the triaxial compression test results of two kinds of carbonatite to accurately analyze the deformation and water inrush characteristics of the surrounding rocks after karst tunnel excavation. The total stress–strain curve of rocks was simplified into four linear stages: the linear elastic stage, strain hardening stage, strain-softening stage, and residual stage. The volumetric strain–axial strain curve was simplified into four corresponding linear stages: the elastic expansion stage, slow expansion stage, rapid expansion stage, and stable expansion stage. The stress hardening–softening model was used to deduce the relationship between the rocks’ mechanical parameters such as cohesion, internal friction angle, dilatancy angle, and plastic strain, as well as the relationship between seepage characteristic parameters such as permeability coefficient, porosity, and volumetric strain. A karst tunnel in Chongqing, China was taken as the engineering background. The stress hardening–softening constitutive model and seepage characteristic parameters were applied to the FLAC3D numerical simulation by the programming language FISH to analyze the stability and water inrush characteristics of karst tunnels in overlying confining caves. The results showed that rock masses between the cave and tunnel were prone to overall sliding instability. Confined water in the karst cave intruded into the tunnel through the shear-slip rupture zone on both sides instead of the shortest path. Two water inrush points existed on the tunnel surface. The variation law of the permeability coefficients of the surrounding rocks could more truly reflect whether there was a seepage channel between the tunnel and karst cave, as well as the permeable area and water inrush speed of the seepage channel. The work provides a new idea for the stability control of karst tunnels.

The repair rate of deep permanent roadways is about 90%, and most of which are projects treating floor heave. The deformation behaviors of crosscut were analyzed in the work according to a trackage crosscut at the shaft station of Panyidong Coal Mine in Huainan, China. Crosscut has complex characteristics such as globality, difference, and rheology under deep stress because that crosscut passes through multiple strata. The mechanism of crosscut floor heave was studied based on on-site in situ stress tests and surrounding rock composition tests. The floor heave of trackage crosscut is water swelling in the mudstone and sandy-mudstone areas where the mineral components are mainly kaolinite and illite mixed layers. In the areas of fine and medium-fine sandstone, trackage crosscut is in shear dislocation under high horizontal stress. The slip-line field theory was used to study the ultimate load and maximum failure depth of crosscut floor heave. According to the deformation characteristics of crosscut floor heave, a collaborative control technology enhancing the bearing structure of all-sided surrounding rocks was proposed, including filling of the U-shaped steel supports, shallow grouting in the all-sided surrounding rocks and deep grouting in the floor and inverted arches. A support scheme for repairing the floor was designed based on the specific engineering geology of trackage crosscut floor heave at the shaft station of the Panyidong Coal Mine. After repairing, the crosscut floor heave was monitored for 70 d. The results showed the following. (1) After repairing, the maximum cumulative floor heave was 45.3 mm, which was only 8.1% of that before repairing. (2) Crosscut floor heave changed greatly within one week after repair, with a maximum floor heave speed of 4.7 mm/d. The floor heave speed was maintained below 1 mm/d after 40 d, and the floor heave tended to be stable after 60 d. The collaborative control technology enhancing the bearing structure of all-sided surrounding rocks could control the crosscut floor heave in soft rocks under deep high horizontal stress.

Geological structures of Sima coal mine in Shanxi Province were analyzed to understand the control effect of the geological structures on the occurrence of coalbed methane (CBM) in coal seam #3 of Sima coal mine. The CBM contents in the districts #2 and #3 of Sima coal mine were tested, and the effects of buried depth, fault and collapse column on the distribution of coalbed methane content are studied. The research results showed that: 1) The average content of CBM has a linear relationship with buried depth and overburden thickness, but in the smallscale range of buried depth, the dispersion between CBM and buried depth is very large. 2) Faults and collapse columns significantly affect the content of local CBM nearby, but from the largescale range such as the whole mining area, the average value of CBM content at a certain buried depth will not be affected by faults and collapse columns. 3) In the hanging wall of F29 normal fault, it is roughly estimated that the average escape rate of CBM near the fault is 13.9%, while in the footwall of F29 normal fault, this value is 0.7%–1.1%. The results show that there is a significant difference in the influence of the fault on the CBM content in the hanging wall and footwall. 4) The control effect of collapse column on CBM occurrence is related to the development height of collapse column, the cementation degree of collapse column, groundwater runoff conditions and other factors. It can be divided into three categories: aggregation action, escape action (such as collapse column X8) and no obvious effect (such as collapse column DX7).

A comprehensive understanding of the mechanical properties of coal and rock sections is necessary for interpreting the deformation and failure modes of such underground sections and for evaluating the potential dynamic hazards. However, most studies have focused on horizontal coal–rock composites and the mechanical properties of inclined coal–rock composites have not been considered. To explore the influence of different confining pressures and inclined coal seam thicknesses on the mechanical properties and failure characteristics of rock–coal–rock (RCR) composites, a numerical model based on the particle flow code was used to perform simulations on five inclined RCR composites at different confining pressures. The results show that the mechanical properties and failure characteristics of the RCR composites are affected considerably by the inclined coal seam thickness and the confining pressure. (1) When the inclined coal seam thickness is constant, the elasticity modulus of the inclined RCR composite increases nonlinearly with the confining pressure at first, and then remains constant. At the same confining pressure, the elasticity modulus of the inclined RCR composite decreases nonlinearly with the inclined coal seam thickness. (2) When the confining pressure is constant, the peak stress of the inclined RCR composite decreases with the increase of the inclined coal seam thickness. When the inclined coal seam thickness is constant, the peak stress increases with the confining pressure. (3) As the inclined coal seam thickness increases, the peak strain of the inclined RCR composite first decreases rapidly, and then remains constant when there is no confining pressure. When the confining pressure is between 5 and 20 MPa, the peak strain of the inclined RCR composite gradually increases. (4) In the absence of confining pressure, there are few microcracks in the rock at an inclined coal seam thickness of 10 mm, whereas all the other cracks are in the coal section. When the confining pressure ranges between 5 and 20 MPa, the failure modes of the RCR composite can be divided into Y- and X-types.

Industrial development and transformation need to rely on engineering education to provide talent support. In view of the inevitable trend of coal mining technology upgrading to intelligence in Guizhou Province, the mining engineering specialty of Liupanshui Normal University has established a smart mining experimental class.Taking this as an example, this paper introduces the path of building smart mining experimental class in mining engineering specialty of application-oriented local colleges from the aspects of teaching staff, curriculum system,practice base inside and outside the school, etc. In terms of the construction of teaching staff, it includes the optimization of the allocation of teachers’ resources, the dynamic optimization of teaching staff, the introduction of specialized talents and the construction of part-time teachers; In the aspect of course construction, different measures can be taken for the existing courses, new courses and original courses with new smart mining content of other majors or colleges of the university; In terms of the construction of practice base, the school mainly builds smart mining virtual simulation practice teaching resources, and outside the school, it cooperates with local enterprises to build a training base.

Due to the low permeability of the coal seam and the low gas extraction rate in conventional boreholes in the Wulunshan Coal Mine in Guizhou, in this study, the deep-hole pre-split blasting method is applied to study the improvement of the gas extraction efficiency by increasing the permeability of the coal seam. The study comprehensively expounds the process in which the deep-hole pre-split blasting method is applied to improve the gas extraction efficiency and proposes a numerical simulation method that combines ANSYS/LS-DYNA and COMSOL Multiphysics. Using the method, the initiation of blasting fracture channels and the subsequent influence on the gas extraction range have been comprehensively and directly researched and analyzed. Finally, some theoretical research has been verified by field experiments. According to the recorded simulation of the Wulunshan Coal Mine, the exposed area of the blasting borehole was 42 times the size of the conventional drilling borehole, and the pressure relief space was 1,050 times that of the conventional drilling borehole, which can connect about 32 m 3 of coal. Compared with conventional drilling boreholes, in the process of gas extraction, the control range of the controlled pressure reduction was 4–7 times, the range of gas pressure reaching the standard was 25 times, and the peak pressure was reduced by 3–5 times. The average gas concentration was 1.85 times that of conventional boreholes, and the cumulative gas extraction volume of blasting boreholes was 4.48 times that of conventional boreholes. The research results prove that the application of blasting and permeability enhancement in the coal seam with a high gas content and low permeability can effectively improve the gas extraction efficiency in the Wulunshan Coal Mine in Guizhou.

Rocks are a typical kind of heterogeneous material composed of differences in size, shape, type, and mineral particle distribution. The strength and deformation characteristics of rocks are controlled by their internal heterogeneous structures. A numerical model was built to analyse the strength and failure characteristics of sandstone samples with randomly distributed heterogeneous. The results revealed that heterogeneous structures induce local stress concentrations and accelerate sample failure. At a loading rate of 0.01 mm/s, the mechanical properties of sandstone samples with soft heterogeneous particles are uniformly smaller than those of standard sandstone samples, while those of sandstone samples with hard heterogeneous particles follow different variation rules, depending on the specific heterogeneous particle content. With the differences between heterogeneous particles and sandstone particles in properties, an increase is observed in the mechanical properties of samples with different heterogeneous particle contents. Soft heterogeneous structures determine the crack initiation position of the main crack and the development and propagation space of cracks through their distribution pattern, while hard heterogeneous structures are load-bearing and change crack propagation paths. When there are multiple structures with different properties in rocks, micro-cracks occur first between soft heterogeneous particles, and the distribution pattern of soft heterogeneous particles determines the ultimate failure mode of samples as well as the propagation paths and development space of cracks.

The increasing use of high-voltage transmission wires requires more and more high-voltage pylons, and sometimes, constructing pylons in mining areas is very urgent. To ensure the safe operation of pylons, coal pillars with large side lengths are usually used to provide sufficient support; however, this results in a huge waste of coal. Eight high-voltage pylons are arranged on the ground surface corresponding to the location of working face 1110 of Sima Coal Mine in Shanxi Province, China, which cannot be mined by traditional methods. Taking this as the engineering background, the failure mode of high-voltage pylon is first analyzed. Using FLAC3D numerical simulations, the influence of five different mining plans on ground surface deformation in working face 1110 is evaluated, and the vertical settlement and horizontal deformation in different areas of the ground surface, as well as the variation law of horizontal strain and slope are analyzed. According to the numerical simulation results, the range of thickness-limiting mining or backfill mining in working face 1110 is shown in scheme 3, and the key regions in the mining process are determined. Secondly, the strengthening scheme of high-voltage pylons is designed, that is, the four foundations of high-voltage pylons are connected as a whole with steel supports and steel connectors so as to improve the structural strength of the high-voltage pylon. Finally, the position change in the foundation of high-voltage pylons was monitored for 22 consecutive months. The results show that the maximum settlement of the high-voltage tower foundation is 3.1 m, which is consistent with the actual mining thickness; The high-voltage pylon was stably moved, and the change in transmission line tension and total length was usually less than 1.0%. The combined mining scheme and foundation strengthening scheme can ensure the safe operation of high-voltage pylons and provide a new method for the stability control of ground buildings in coal mining subsidence area.