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Experimental study on the influence of roadway shape on the evolution of outburst fluid static pressure

International Journal of Coal Science & Technology 2024年第4期11卷 274-289页

作者： Jiang Xu Xiaomei Wang Liang Cheng Shoujian Peng Hailin Yang Bin Zhou Feng Jiao State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400030China College of Safety Science and Engineering Xian University of Science and TechnologyXian 710054ShaanxiChina

To explore the static pressure dynamic disaster mechanism of coal-and-gas outburst(CGO)fluid,the self-developed multifield coupling large-scale physical simulation test system of coal mine dynamic disaster was used to carry out gas outburst and CGO physical simulation tests in straight,L-shaped and T-shaped *** influence of roadway shape on the evolution of static pressure was explored,and the role of pulverized coal in the process of static pressure dynamic disaster was *** results indicated that the static pressure showed a fluctuating downward trend during the outburst *** gas outburst,the middle and front parts of the roadway in the straight section roadway were the most serious areas of static pressure disasters in the three shapes of *** duration and range of high static pressure disaster in L-shaped roadway were larger than those in T-shaped and straight roadways in *** CGO,the most serious area of static pressure disaster in L-shaped and T-shaped roadways moved backward to the middle of the straight section roadway,and there was a rebound phenomenon in the process of static pressure fluctuation decline,which showed the pulse characteristics of *** the outburst,the static pressure dynamic disaster hazard of L-shaped roadway was higher than that of T-shaped roadway,and the static pressure at the bifurcation structure decayed faster than that at the turning structure,which indicated that T-shaped roadway was more conducive to the release of static pressure in roadway,thus reduced the risk of static pressure *** gas outburst,the static pressure attenuation of the fuid in the roadway before and after the turning and bifurcation structure was greater than that of *** peak static pressure and impulse of the fluid during gas outburst were 2 times and 4-5 times that of CGO *** presence of pulverized coal reduced the attenuation of static pressure and the hazard of dynamic disaster,prolonged

关键词： Gas outburst Coal-and-gas outburst.Static pressure Roadway shape Dynamic disaster.Outburst fluid

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Stability analysis of karst anti dip rock slope induced by underground coal mining——A case study of Jiguanling landslide, China

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Journal of Mountain Science 2025年第4期22卷 1226-1244页

作者： ZHONG Zuliang LIANG Erwei WANG Nanyun XU Yawei School of Civil Engineering Chongqing UniversityChongqing 400045China State key laboratory of coal mine disaster dynamics and control Chongqing 400044China Key Laboratory of New Technology for Construction of Cities in Mountain Area of Ministry of Education Chongqing 400045China

In recent years,the southwestern region of China has experienced a surge in significant mountain collapses,predominantly linked to underground mining *** investigation targets the Jiguanling area in Wulong,Chongqing,employing the UDEC numerical simulation technique to meticulously examine the deformation and failure characteristics,rock mass movement patterns,fracture evolution processes,and stress transmission mechanisms of anti-dip rock slopes composed of stratified *** slopes are inherently susceptible to bending and tilting due to their own *** findings elucidate that the predominant failure mode of anti-dip rock karst slopes is the inclined sliding(shear)type,which mirrors the fracture evolution mechanism as they extend in a quadrilateral pattern from the top and bottom plates of the mining area to the critical blocks at the rear and front edges of the *** disaster mechanism can be encapsulated as the"initial roof movement phase,direct roof collapse and crack propagation phase,critical block locking and sliding resistance phase,and deterioration phase".The four distinct stages of development and transformation encompass critical block slip(shear)and slope instability *** increase in coal seam thickness enlarges the deformation space in the lower part,while the dip angle of the coal seam influences the length and displacement range of rock fracture *** mining sequence alters the stress failure mode of the underlying critical blocks,and the vertical height of the mining step distance modifies the potential sliding surface and failure mode of the underlying critical ***,the distance between the goaf and the surface,along with the height of the mining impact,impacts the stability of the reverse *** results demonstrate that mining activities are the primary factor inducing the collapse of anti-dip rock slopes,with natural factors playing a secondary role.

关键词： Anti-dip rock slope Mining action Slope deformation mechanism Slope instability mechanism Evolution law of cracks

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Microstructural evolution and hydraulic response of shale self-propped fracture using X-ray computed tomography and digital volume correlation

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International Journal of Mining Science and Technology 2025年第3期35卷 345-362页

作者： Ting Huang Cheng Zhai Ting Liu Yong Sun Hexiang Xu Yu Wang Jing Huang State Key Laboratory of Coal Mine Disaster Prevention and Control Ministry of EducationChina University of Mining and TechnologyXuzhou 221116China Key Laboratory of Theory and Technology on Coal and Rock Dynamic Disaster Prevention and Control National Mine Safety AdministrationChina University of Mining and TechnologyXuzhou 221116China School of Safety Engineering China University of Mining and TechnologyXuzhou 221116China School of Low-Carbon Energy and Power Engineering China University of Mining and TechnologyXuzhou 221116China

Methane in-situ explosive fracturing technology produces shale debris particles within fracture channels,enabling a self-propping effect that enhances the fracture network conductivity and long-term *** study employs X-ray computed tomography(CT)and digital volume correlation(DVC)to investigate the microstructural evolution and hydromechanical responses of shale self-propped fracture under varying confining pressures,highlighting the critical role of shale particles in maintaining fracture *** indicate that the fracture aperture in the self-propped sample is significantly larger than in the unpropped sample throughout the loading process,with shale particles tending to crush rather than embedded into the matrix,thus maintaining flow *** confining pressure increases,contact areas between fracture surfaces and particles expand,enhancing the system's stability and compressive *** analyses show flow paths becoming increasingly concentrated and branched under high *** resulted in a significant reduction in connectivity,restricting fracture permeability and amplifying the nonlinear gas flow *** study introduces a permeability-strain recovery zone and a novel sensitivity parameter m,delineating stress sensitivity boundaries for permeability and normal strain,with m-value increasing with stress,revealing four characteristic *** findings offer theoretical support for optimizing fracturing techniques to enhance resource extraction efficiency.

关键词： Digital volume correlation X-ray CT scanning Fracture aperture Deformation characteristics Stress sensitivity Permeability

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A novel frequency-division deep-learning approach for magnetotelluric data quality enhancement

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Geophysics 2025年第3期90卷 WA169-WA187页

作者： Yu, Nian Ji, Mingjie Zhang, Chao Ye, Yi Zhou, Wei Chongqing University School of Electrical Engineering Chongqing China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing China Chongqing University School of Resources and Safety Engineering Chongqing China

High signal-To-noise ratio magnetotelluric (MT) data are crucial for accurately interpreting subsurface structures. Recently, deep learning has become popular for MT denoising due to its ability to avoid parameter tuning and enable real-Time processing. These methods typically fit or predict signals in noisy segments after identifying and segmenting signal and noise in the time domain. However, these methods struggle to preserve low-And high-frequency signals effectively due to high noise levels in these segments. To address this issue, we develop a novel deep-learning denoising method that separately recovers low-And high-frequency signals using distinct strategies. Low-frequency signals are fitted using an inverse autoencoder with a channel attention mechanism, effectively removing high-frequency components. High-frequency signals are then predicted using a bidirectional long short-Term memory network combined with a squeeze-And-excitation mechanism, enhancing prediction by considering global and local signal characteristics. In addition, we introduce the multivariate state estimation technique (MSET) for real-Time signal-noise identification. MSET analyzes residuals after separating low-frequency signals to identify noise. Denoising is performed only on segments with significant noise, preserving more effective signals. Finally, the fitted low-frequency dominant and predicted high-frequency components are combined to form the denoised MT signals. This combined approach significantly improves the restoration quality of effective signals compared with existing methods. Experimental results demonstrate that our method exhibits superior denoising capabilities in quantitative and qualitative evaluations, including apparent resistivity-phase curves and polarization direction analysis, offering enhanced performance over current deep-learning methods. © 2025 Society of Exploration Geophysicists. All rights reserved.

关键词： Signal to noise ratio

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Theoretical and Experimental Study on Tension–Torsion Coupling Vibration for Time-Varying Elevator Traction System

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Acta Mechanica Solida Sinica 2023年第6期36卷 899-913页

作者： Peng Xu Qifeng Peng Fusong Jin Jianghong Xue Hong Yuan MOE Key Laboratory of Disaster Forecast and Control in Engineering School of Mechanics and Construction EngineeringJinan UniversityGuangzhou 51063China University of Health and Rehabilitation Sciences Qingdao 266071China School of Architectural Engineering Guangzhou Institute of Science and TechnologyGuangzhou 510540China Qingdao Xinghua Intelligent Equipment Co. Ltd.Qingdao 266114China

Elevators used in ultra-high buildings are prone to vibrating due to their ultra-long traction ropes,which significantly affects the comfort and safety of high-speed ***,vibration of the elevator has always been a topic of research *** paper presents a theoretical model for analyzing the tension–torsion coupling vibration of the time-varying elevator traction *** constitutive relations with the tension–torsion coupling effect of the wire rope are reduced by analyzing the deformation mechanism of the spiral winding wire *** on Hamilton’s principle,the equations of motion and corresponding boundary conditions for the tension–torsion coupling vibration of the elevator traction system are *** Galerkin method is employed to account for the influence of nonlinear boundary conditions and to transform the equations of motion into discrete ones with variable coefficients of time,which are solved using the Newmark-β*** accuracy of the proposed model is justified by the good agreement between theoretical predictions and experimental results,following which,the influence of the operation status and structural parameters of the elevator traction system on its vibration performance is discussed in detail.

关键词： Elevator traction system Wire rope Tension–torsion vibration Time-varying

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Energy dissipation mechanism and ballistic characteristic optimization in foam sandwich panels against spherical projectile impact

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Defence Technology（防务技术） 2024年第5期35卷 108-122页

作者： Jianqiang Deng Tao Liu Liming Chen Xin Pan Jingzhe Wang Shaowei Zhu Weiguo Li College of Aerospace Engineering Chongqing UniversityChongqing 400030China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400030China Chongqing Key Laboratory of Heterogeneous Material Mechanics Chongqing UniversityChongqing 400030China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

This study systematically examines the energy dissipation mechanisms and ballistic characteristics of foam sandwich panels(FSP)under high-velocity impact using the explicit non-linear finite element *** on the geometric topology of the FSP system,three FSP configurations with the same areal density are derived,namely multi-layer,gradient core and asymmetric face sheet,and three key structural parameters are identified:core thickness(t_(c)),face sheet thickness(t_(f))and overlap face/core number(n_(o)).The ballistic performance of the FSP system is comprehensively evaluated in terms of the ballistic limit velocity(BLV),deformation modes,energy dissipation mechanism,and specific penetration energy(SPE).The results show that the FSP system exhibits a significant configuration dependence,whose ballistic performance ranking is:asymmetric face sheet>gradient core>*** mass distribution of the top and bottom face sheets plays a critical role in the ballistic resistance of the FSP *** BLV and SPE increase with tf,while the raising tcor noleads to an increase in BLV but a decrease in ***,a face-core synchronous enhancement mechanism is discovered by the energy dissipation analysis,based on which the ballistic optimization procedure is also conducted and a design chart is *** study shed light on the anti-penetration mechanism of the FSP system and might provide a theoretical basis for its engineering application.

关键词： Sandwich panel Numerical simulation Ballistic resistance Specific penetration energy Energy analysis

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Effects of aggregate size distribution and carbon nanotubes on the mechanical properties of cemented gangue backfill samples under true triaxial compression

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 311-324页

作者： Qian Yin Fan Wen Zhigang Tao Hai Pu Tianci Deng Yaoyao Meng Qingbin Meng Hongwen Jing Bo Meng Jiangyu Wu State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines Anhui University of Science and TechnologyHuainan 232001China State Key Laboratory for Geomechanics&Deep Underground Engineering China University of Mining and Technology(Beijing)Beijing 100083China Key Laboratory of Xinjiang Coal Resources Green Mining Ministry of EducationXinjiang Institute of EngineeringUrumqi 830023China

The mechanical behavior of cemented gangue backfill materials(CGBMs)is closely related to particle size distribution(PSD)of aggregates and properties of cementitious ***,the true triaxial compression tests,CT scanning,SEM,and EDS tests were conducted on cemented gangue backfill samples(CGBSs)with various carbon nanotube concentrations(P_(CNT))that satisfied fractal theory for the PSD of *** mechanical properties,energy dissipations,and failure mechanisms of the CGBSs under true triaxial compression were systematically *** results indicate that appropriate carbon nanotubes(CNTs)effectively enhance the mechanical properties and energy dissipations of CGBSs through micropore filling and microcrack bridging,and the optimal effect appears at P_(CNT)of 0.08wt%.Taking PSD fractal dimension(D)of 2.500 as an example,compared to that of CGBS without CNT,the peak strength(σ_(p)),axial peak strain(ε_(1,p)),elastic strain energy(Ue),and dissipated energy(U_(d))increased by 12.76%,29.60%,19.05%,and90.39%,***,excessive CNTs can reduce the mechanical properties of CGBSs due to CNT agglomeration,manifesting a decrease inρ_(p),ε_(1,p),and the volumetric strain increment(Δε_(v))when P_(CNT)increases from 0.08wt%to 0.12wt%.Moreover,the addition of CNTs improved the integrity of CGBS after macroscopic failure,and crack extension in CGBSs appeared in two modes:detour and pass through the ***σ_(p)and U_(d)firstly increase and then decrease with increasing D,and porosity shows the opposite ***ε_(1,p)andΔε_(v)are negatively correlated with D,and CGBS with D=2.150 has the maximum deformation parameters(ε_(1,p)=0.05079,Δε_(v)=0.01990)due to the frictional slip effect caused by coarse *** increasing D,the failure modes of CGBSs are sequentially manifested as oblique shear failure,"Y-shaped"shear failure,and conjugate shear failure.

关键词： cemented gangue backfill materials particle size distribution true triaxial compression test carbon nanotubes mechanical properties failure modes

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A new type of shale gas reservoir—carbonate-rich shale: From laboratory mechanical characterization to field stimulation strategy

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Petroleum Science 2024年第5期21卷 3047-3061页

作者： Zhen-Hui Bi Lei Wang Chun-He Yang Yin-Tong Guo Wu-Hao Guo Han-Zhi Yang Key Laboratory of Geomechanics and Geotechnical Engineering Safety Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071HubeiChina University of Chinese Academy of Sciences Beijing100049China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing400044China

Recently, a new promising type of marine shale gas reservoir, carbonate-rich shale, has been *** the mechanical properties of this type of shale were still unrevealed and the corresponding reservoir stimulation design was lack of guidance. Using the deep downhole cores of an exploratory carbonate-rich shale gas well, the physical and mechanical parameters and failure mechanism of the whole reservoir section were acquired and evaluated systematically, by performing XRD, tri-axial compression, Brazilian splitting, and fracture toughness tests. A new model was established to evaluate the reservoir brittleness based on fracture morphology and stress-strain curve. Recommended strategy for reservoir stimulation was discussed. Results showed that(1) Carbonate-rich shale possessed high compressive strength and high Young's modulus, which were improved by 10.74% and 3.37% compared to that of siliceous shale. It featured high tensile strength and fracture toughness, with insignificant anisotropy.(2) With the content of carbonate minerals increasing, the shear failure morphology transformed from sparse and wide brittle fractures to diffusely distributed and subtle plastic cracks.(3) The brittleness index order was: siliceous shale, clay-rich shale, carbonate-rich shale, and limestone.(4) The special properties of carbonate-rich shale were rooted in the inherent feature of carbonate minerals(high strength, high elastic modulus,and cleavage structure), resulting in greater challenge in reservoirs stimulation. The above findings would promote the understanding of carbonate-rich shale reservoirs and provide reference for the optimum design of reservoir stimulation.

关键词： Carbonate-rich shale Brittleness evaluation Mechanical property Lithological difference Reservoir stimulation

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A novel binary effective medium model to describe the prepeak stressstrain relationship of combined bodies of rock-like material and rock

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International Journal of Mining Science and Technology 2023年第5期33卷 601-616页

作者： Tienan Wang Yue Zhai Huan Gao Yubai Li Ruifeng Zhao School of Geological Engineering and Geomatics Chang’an UniversityXi’an 710064China Key Laboratory of Mine Geological Disaster Hazard Mechanism and Control Ministry of Natural ResourcesXi’an 710064China

Combined bodies of rock-like material and rock are widely encountered in geotechnical engineering,such as tunnels and *** existing theoretical models describing the stress-strain relationship of a combined body lack a binary *** on effective medium theory,this paper presents the governing equation of the“elastic modulus”for combined and single bodies under triaxial compressive tests.A binary effective medium model is then *** on the compressive experiment of concretegranite combined bodies,the feasibility of determining the stress threshold based on crack axial strain is discussed,and the model is *** model is further extended to coal-rock combined bodies of more diverse types,and the variation laws of the compressive mechanical parameters are then *** results show that the fitting accuracy of the model with the experimental curves of the concretegranite combined bodies and various types of coal-rock combined bodies are over 95%.The crack axial strain method can replace the crack volumetric strain method,which clarifies the physical meanings of the model *** variation laws of matrix parameters and crack parameters are discussed in depth and are expected to be more widely used in geotechnical engineering.

关键词： Combined body stress-strain relationship Hooke’s law Effective medium theory Stress threshold determination

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Channel pruning method driven by similarity of feature extraction capability

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Soft Computing 2025年第2期29卷 1207-1226页

作者： Sun, Chuanmeng Chen, Jiaxin Li, Yong Wang, Yu Ma, Tiehua State Key Laboratory of Dynamic Measurement Technology North University of China Shanxi Taiyuan030051 China School of Electrical and Control Engineering North University of China Shanxi Taiyuan030051 China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing University Chongqing400044 China

Channel pruning is a method to compress convolutional neural networks, which can significantly reduce the number of model parameters and the computational amount. Current methods that focus on the internal parameters of a model and feature mapping information rely on artificially set a priori criteria or reflect filter attributes by partial feature mapping, which lack the ability to analyze and discriminate the channel feature extraction and ignore the basic reasons for the similarity of the channels. This study developed a pruning method based on similar structural features of channels, called SSF. This method focuses on analysing the ability to extract similar features between channels and exploring the characteristics of channels producing similar feature mapping. First, adaptive threshold coding was introduced to numerically transform the channel characteristics into structural features, and channels with similar coding results could generate highly similar feature mapping. Secondly, the spatial distance was calculated for the structural features matrix to obtain the similarity between channels. Moreover, in order to keep rich channel classes in the pruned network, different class cuts were made on the basis of similarity to randomly remove some of the channels. Thirdly, considering the differences in the overall similarity of different layers, this study determined the appropriate pruning ratio for different layers on the basis of the channel dispersion degree reflected by the similarity. Finally, extensive experiments were conducted on image classification tasks, and the experimental results demonstrated the superiority of the SSF method over many existing techniques. On ILSVRC-2012, the SSF method reduced the floating-point operations (FLOPs) of the ResNet-50 model by 57.70% while reducing the Top-1 accuracy only by 1.01%. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.

关键词： Convolutional neural networks

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