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Sub-Homogeneous Peridynamic Model for Fracture and Failure Analysis of Roadway Surrounding Rock
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作者 Shijun Zhao Qing Zhang +3 位作者 Yusong Miao Weizhao Zhang Xinbo Zhao Wei Xu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期3167-3187,共21页
The surrounding rock of roadways exhibits intricate characteristics of discontinuity and heterogeneity.To address these complexities,this study employs non-local Peridynamics(PD)theory and reconstructs the kernel func... The surrounding rock of roadways exhibits intricate characteristics of discontinuity and heterogeneity.To address these complexities,this study employs non-local Peridynamics(PD)theory and reconstructs the kernel function to represent accurately the spatial decline of long-range force.Additionally,modifications to the traditional bondbased PD model are made.By considering the micro-structure of coal-rock materials within a uniform discrete model,heterogeneity characterized by bond random pre-breaking is introduced.This approach facilitates the proposal of a novel model capable of handling the random distribution characteristics of material heterogeneity,rendering the PD model suitable for analyzing the deformation and failure of heterogeneous layered coal-rock mass structures.The established numerical model and simulation method,termed the sub-homogeneous PD model,not only incorporates the support effect but also captures accurately the random heterogeneous micro-structure of roadway surrounding rock.The simulation results obtained using this model show good agreement with field measurements from the Fucun coal mine,effectively validating the model’s capability in accurately reproducing the deformation and failure mode of surrounding rock under bolt-supported(anchor cable).The proposed subhomogeneous PD model presents a valuable and effective simulation tool for studying the deformation and failure of roadway surrounding rock in coal mines,offering new insights and potential advancements. 展开更多
关键词 roadway surrounding rock PERIDYNAMICS heterogeneous material fracture analysis numerical simulation
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Instability mechanism of mining roadway passing through fault at different angles in kilometre-deep mine and control measures of roof cutting and NPR cables
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作者 SUN Xiaoming WANG Jian +6 位作者 ZHAO Wenchao MING Jiang ZHANG Yong LI Zhihu MIAO Chengyu GUO Zhibiao HE Manchao 《Journal of Mountain Science》 SCIE CSCD 2024年第1期236-251,共16页
The angle α between the fault strike and the axial direction of the roadway produces different damage characteristics. In this paper, the research methodology includes theoretical analyses, numerical simulations and ... The angle α between the fault strike and the axial direction of the roadway produces different damage characteristics. In this paper, the research methodology includes theoretical analyses, numerical simulations and field experiments in the context of the Daqiang coal mine located in Shenyang, China. The stability control countermeasure of "pre-splitting cutting roof + NPR anchor cable"(PSCR-NPR) is simultaneously proposed. According to the different deformation characteristics of the roadway, the faults are innovatively classified into three types, with α of type I being 0°-30°, α of type II being 30°-60°, and α of type III being 60°-90°. The full-cycle stress evolution paths during mining roadway traverses across different types of faults are investigated by numerical simulation. Different pinch angles α lead to high stress concentration areas at different locations in the surrounding rock. The non-uniform stress field formed in the shallow surrounding rock is an important reason for the instability of the roadway. The pre-cracked cut top shifted the high stress region to the deep rock mass and formed a low stress region in the shallow rock mass. The high prestressing NPR anchor cable transforms the non-uniform stress field of the shallow surrounding rock into a uniform stress field. PSCR-NPR is applied in the fault-through roadway of Daqiang mine. The low stress area of the surrounding rock was enlarged by 3-7 times, and the cumulative convergence was reduced by 45%-50%. It provides a reference for the stability control of the deep fault-through mining roadway. 展开更多
关键词 Kilometre-deep mine Fault Mining roadway Failure mechanism Pre-splitting cutting roof High pre-stress NPR anchor cable
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The Impact of Sea Level Rise on Roadway Design and Evacuation Routes in Delaware
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作者 Jack Palevich Ardeshir Faghri Ahmet Karakurt 《American Journal of Climate Change》 2024年第1期69-82,共14页
As the global temperature continues to increase, the sea level continues to rise at a rapid rate that has never been seen before. This becomes an issue for many facets of life but one of the most impacted is the trans... As the global temperature continues to increase, the sea level continues to rise at a rapid rate that has never been seen before. This becomes an issue for many facets of life but one of the most impacted is the transportation infrastructure. Many people living in low elevation coastal areas can become trapped by flooding with no way in or out. With Delaware being a coastal state, this would affect a large portion of the population and will have detrimental effects over time if nothing is done to combat sea level rise. The issue with sea level rise in transportation is that once the roads become flooded, they become virtually unusable and detour routes would be needed. If all the roads in a coastal area were to be affected by sea level rise, the options for detours would become limited. This article looks at direct solutions to combat sea level rise and indirect solutions that would specifically help transportation infrastructure and evacuation routes in Delaware. There is not one solution that can fix every problem, so many solutions are laid out to see what is applicable to each affected area. Some solutions include defense structures that would be put close to the coast, raising the elevation of vulnerable roads throughout the state and including pumping stations to drain the water on the surface of the road. With an understanding of all these solutions around the world, the ultimate conclusion came in the form of a six-step plan that Delaware should take in order to best design against sea level rise in these coastal areas. 展开更多
关键词 Sea Level Rise roadway Design Evacuation Routes
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Theory,technology and application of grouted bolting in soft rock roadways of deep coal mines
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作者 Hongpu Kang Jianwei Yang +4 位作者 Pengfei Jiang Fuqiang Gao Wenzhou Li Jiafeng Li Huiyuan Chen 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第7期1463-1479,共17页
The grouted bolt,combining rock bolting with grouting techniques,provides an effective solution for controlling the surrounding rock in deep soft rock and fractured roadways.It has been extensively applied in numerous... The grouted bolt,combining rock bolting with grouting techniques,provides an effective solution for controlling the surrounding rock in deep soft rock and fractured roadways.It has been extensively applied in numerous deep mining areas characterized by soft rock roadways,where it has demonstrated remarkable control results.This article systematically explores the evolution of grouted bolting,covering its theoretical foundations,design methods,materials,construction processes,monitoring measures,and methods for assessing its effectiveness.The overview encompassed several key elements,delving into anchoring theory and grouting reinforcement theory.The new principle of high pretensioned high-pressure splitting grouted bolting collaborative active control is introduced.A fresh method for dynamic information design is also highlighted.The discussion touches on both conventional grouting rock bolts and cable bolts,as well as innovative grouted rock bolts and cables characterized by their high pretension,strength,and sealing hole pressure.An examination of the merits and demerits of standard inorganic and organic grouting materials versus the new inorganic–organic composite materials,including their specific application conditions,was conducted.Additionally,the article presents various methods and instruments to assess the support effect of grouting rock bolts,cable bolts,and grouting reinforcement.Furthermore,it provides a foundation for understanding the factors influencing decisions on grouted bolting timing,the sequence of grouting,the pressure applied,the volume of grout used,and the strategic arrangement of grouted rock bolts and cable bolts.The application of the high pretensioned high-pressure splitting grouted bolting collaborative control technology in a typical kilometer-deep soft rock mine in China—the soft coal seam and soft rock roadway in the Kouzidong coal mine,Huainan coal mining area,was introduced.Finally,the existing problems in grouted bolting control technology for deep soft rock roadways are analyzed,and the future development trend of grouted bolting control technology is anticipated. 展开更多
关键词 deep coal mine soft rock roadway grouted bolting rock bolt and cable grouting material high-pressure splitting grouting collaborative control technology
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Surrounding Rock Control Technology of Strong Dynamic Pressure Roadway in Hudi Coal Industry
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作者 Yixue Jia 《World Journal of Engineering and Technology》 2024年第2期362-372,共11页
Aiming at the problems of large deformation and difficult maintenance of deep soft rock roadway under the influence of high ground stress and strong dynamic pressure, taking the surrounding rock control of 1105 lane i... Aiming at the problems of large deformation and difficult maintenance of deep soft rock roadway under the influence of high ground stress and strong dynamic pressure, taking the surrounding rock control of 1105 lane in Hudi Coal Industry as an example, the deformation characteristics and surrounding rock control measures of deep soft rock roadway are analyzed and discussed by means of geological data analysis, roadway deformation monitoring, rock crack drilling and field test. The results show that the main causes of roadway deformation are high ground stress, synclinal tectonic stress, advance mining stress, roadway penetration and surrounding rock fissure development. Based on the deformation characteristics and mechanism of lane 1105, the supporting countermeasures of “roof synergic support, layered grouting, anchor cable beam support, closed hardening of roadway surface” are proposed, which can provide reference for the control of deep roadway surrounding rock under similar conditions. 展开更多
关键词 Deep roadway Combined Support Surrounding Rock Control Soft Rock roadway
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Research on the "three shells" cooperative support technology of large-section chambers in deep mines 被引量:1
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作者 Cheng Zhu Yong Yuan +3 位作者 Wenmiao Wang Zhongshun Chen Shengzhi Wang Huiwei Zhong 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2021年第4期665-680,共16页
The"three shells"cooperative support technology was proposed herein according to both the large deformation of the rock surrounding large-section chambers in deep mines and the precarious stability of the su... The"three shells"cooperative support technology was proposed herein according to both the large deformation of the rock surrounding large-section chambers in deep mines and the precarious stability of the support structures therein.The development range of the plastic zone in the surrounding rock was controlled by a stress shell to reduce the difficulty of controlling the surrounding rock.Additionally,the residual strength of the rock mass in the plastic zone and the self-bearing capacity of the surrounding rock were improved by a reinforced load-bearing shell.Furthermore,a passive load-bearing shell could restore the triaxial stress state of the surrounding rock on the free surface,reduce the influence of the external environment on the surrounding rock,and reinforce the surrounding rock with the strength of the shell.Reasonable layouts of large-section chambers were determined by analyzing the control effect of the stress shell on the surrounding rock under three kinds of in situ stress fields.The orthogonal test method was applied to reveal the influences of different support parameters in the reinforced loadbearing shell and passive load-bearing shell on the surrounding rock stability.The surrounding rock control effect of the"three shells"collaborative support technology was analyzed through numerical simulation and field monitoring.The results show that the maximum displacement between the roof and floor of the coal preparation chamber in the Xinjulong coal mine was approximately 48 mm,and the maximum displacement between its two sides was approximately 65 mm,indicating that the technology proposed herein could meet the long-term control requirements of the surrounding rock stability for large-section chambers in deep mines. 展开更多
关键词 Deep mining large-section chamber "Three shells"cooperative support Reasonable layout Surrounding rock control
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Stability control measures for roof cutting and NPR supporting of mining roadways in fault areas of kilometre-deep coal mine 被引量:1
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作者 SUN Xiao-ming WANG Jian +5 位作者 ZHANG Yong ZHAO Wen-chao GUO Zhi-biao HE Man-chao CHEN Feng MIAO Cheng-yu 《Journal of Mountain Science》 SCIE CSCD 2023年第10期3051-3065,共15页
The study focuses on the stability control measures for mining roadways in fault zones of deep mines,using Daqiang Coal Mine as a case study.The control system under consideration,referred to as"pre-splitting cut... The study focuses on the stability control measures for mining roadways in fault zones of deep mines,using Daqiang Coal Mine as a case study.The control system under consideration,referred to as"pre-splitting cutting roof+NPR anchor cable"(PSCR-NPR),is subjected to scrutiny through theoretical analysis,numerical modelling,and field trials.Furthermore,a comprehensive analysis is undertaken to evaluate the stability control mechanism of this particular technology.The study provides evidence that the utilization of deep-hole directional energy-concentrated blasting facilitates the attainment of directional roof cutting in roadways.The aforementioned procedure leads to the formation of a uniform structural surface on the roof of the roadway and causes modifications in the surrounding geological formation.The examination of the lateral abutment pressure and shear stress distribution,both prior to and subsequent to roof cutting,indicates that the implementation of pre-splitting techniques leads to a noteworthy reduction in pressure.The proposition of incorporating the safety factor Q for roof cutting height is suggested as a method to augment comprehension of the pressure relief phenomenon in the field of engineering.The analysis of numerical simulation has indicated that the optimal pressure relief effect of a mining roadway in a fault area is attained when the value of Q is 1.8.The NPR anchor cable exhibits noteworthy characteristics,including a high level of prestress,continuous resistance,and substantial deformation.After the excavation of the roadway,a notable reduction in radial stress occurs,leading to the reinstatement of the three-phase stress state in the surrounding rock.This restoration is attributed to the substantial prestress exerted on the radial stress.The termination point of the NPR anchor cable is strategically positioned within a stable rock formation,allowing for the utilization of the mechanical characteristics of the deep stable rock mass.This positioning serves to improve the load-bearing capacity of the surrounding rock.The mining roadway within the fault region of Daqiang Coal Mine is outfitted with the PSCR-NPR technology.The drop in shear stress experienced by the rock surrounding the roadway is estimated to be around 30%,whilst the low-stress region of the mining roadway extends by a factor of approximately 5.5.The magnitude of surface displacement convergence experiences a decrease of approximately 45%-50%.The study’s findings provide useful insights regarding the stable of mining roadway in characterized by fault zones. 展开更多
关键词 Kilometre-deep mine FAULT Mining roadway Pre-splitting cutting roof High pre-stress NPR anchor cable
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Grouting theories and technologies for the reinforcement of fractured rocks surrounding deep roadways 被引量:1
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作者 Hongpu Kang Wenzhou Li +1 位作者 Fuqiang Gao Jianwei Yang 《Deep Underground Science and Engineering》 2023年第1期2-19,共18页
Grouting is an effective method to improve the integrity and stability of fractured rocks that surround deep roadways.After years of research and practice,various theories and a complete set of grouting technologies f... Grouting is an effective method to improve the integrity and stability of fractured rocks that surround deep roadways.After years of research and practice,various theories and a complete set of grouting technologies for deep roadways with fractured rocks have been developed and are widely applied in Chinese coal mining production.This paper systematically summarizes and analyzes the research results concerning the theory,design,materials,processes,and equipment for the grouting and reinforcement of fractured rocks surrounding deep roadways.Specifically,in terms of grouting methods,pregrouting,groutingwhile-excavation,and postgrouting methods are explored;in terms of grouting theory,backfill grouting,compaction grouting,infiltration grouting,and fracture grouting theories are studied.In addition,this paper also studies grouting borehole arrangement,water-cement ratio,grouting pressure,grouting volume,grout diffusion radius,and other grouting parameters and their determination methods.On this basis,this paper explores the physical and mechanical properties of organic and organic-inorganic composite grouting materials,and assess grouting reinforcement quality testing methods and instruments.Taken as the field cases,the application of pregrouting in front of heading faces,groutingwhile-excavation,and postgrouting in the Kouzidong coal mine are then introduced,and the effects of the grouting reinforcements are evaluated.This paper proposes a development direction for grouting technology based on problems existing in the grouting reinforcement of fractured rocks surrounding deep roadways. 展开更多
关键词 deep roadways development direction field study fractured rocks grouting materials grouting methods high-pressure grouting
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Evaluation of roof cutting by directionally single cracking technique in automatic roadway formation for thick coal seam mining
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作者 Yubing Gao Qiukai Gai +2 位作者 Xingxing Zhang Xun Xi Manchao He 《International Journal of Coal Science & Technology》 EI CAS CSCD 2023年第5期137-157,共21页
Automatic roadway formation by roof cutting is a sustainable nonpillar mining method that has the potential to increase coal recovery,reduce roadway excavation and improve mining safety.In this method,roof cutting is ... Automatic roadway formation by roof cutting is a sustainable nonpillar mining method that has the potential to increase coal recovery,reduce roadway excavation and improve mining safety.In this method,roof cutting is the key process for stress relief,which significantly affects the stability of the formed roadway.This paper presents a directionally single cracking(DSC)technique for roof cutting with considerations of rock properties.The mechanism of the DSC technique was investi-gated by explicit finite element analyses.The DSC technique and roof cutting parameters were evaluated by discrete element simulation and field experiment.On this basis,the optimized DSC technique was tested in the field.The results indicate that the DSC technique could effectively control the blast-induced stress distribution and crack propagation in the roof rock,thus,achieve directionally single cracking on the roadway roof.The DsC technique for roof cutting with optimized parameters could effectively reduce the deformation and improve the stability of the formed roadway.Field engineering application verified the feasibility and effectiveness of the evaluated DSC technique for roof cutting. 展开更多
关键词 No pillar mining Automatic roadway formation Directionally single cracking Roof cutting roadway stability-Thick coal seam mining
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Dynamic behavior of outburst two-phase flow in a coal mine T-shaped roadway:The formation of impact airflow and its disaster-causing effect
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作者 Liang Cheng Jiang Xu +4 位作者 Shoujian Peng Hailin Yang Feng Jiao Bin Zhou Fazhi Yan 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第8期1001-1017,共17页
The study of the dynamic disaster mechanism of coal and gas outburst two-phase flow is crucial for improving disaster reduction and rescue ability of coal mine outburst accidents.An outburst test in a T-shaped roadway... The study of the dynamic disaster mechanism of coal and gas outburst two-phase flow is crucial for improving disaster reduction and rescue ability of coal mine outburst accidents.An outburst test in a T-shaped roadway was conducted using a self-developed large-scale outburst dynamic disaster test system.We investigated the release characteristics of main energy sources in coal seam,and obtained the dynamic characteristics of outburst two-phase flow in a roadway.Additionally,we established a formation model for outburst impact flow and a model for its flow in a bifurcated structure.The results indicate that the outburst process exhibits pulse characteristics,and the rapid destruction process of coal seam and the blocking state of gas flow are the main causes of the pulse phenomenon.The outburst energy is released in stages,and the elastic potential energy is released in the vertical direction before the horizontal direction.In a straight roadway,the impact force oscillates along the roadway.With an increase in the solid–gas ratio,the two-phase flow impact force gradually increases,and the disaster range extends from the middle of the roadway to the coal seam.In the area near the coal seam,the disaster caused by the two-phase flow impact is characterized by intermittent recovery.In a bifurcated roadway,the effect of impact airflow on impact dynamic disaster is much higher than that of two-phase flow,and the impact force tends to weaken with increasing solid-gas ratio.The impact force is asymmetrically distributed;it is higher on the left of the bifurcated roadway.With an increase in the solid-gas ratio,the static pressure rapidly decreases,and the bifurcated structure accelerates the attenuation of static pressure.Moreover,secondary acceleration is observed when the shock wave moves along the T-shaped roadway,indicating that the bifurcated structure increases the shock wave velocity. 展开更多
关键词 Multiphase flow Coal and gas outburst Dynamic disaster Impact airflow T-shaped bifurcated roadway Coal seam
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Research on Bolt Support Technology in Soft Coal Seam Roadway
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作者 Xinyuan Ma Wenzhong Zhou +2 位作者 Shuai Zhao Mingxuan Jiang Zihao Yu 《World Journal of Engineering and Technology》 2023年第2期370-380,共11页
In order to solve the problem of surrounding rock control in soft coal seam roadway, taking the centralized return airway of No. 2 coal seam in Liangdu Coal Industry as the research background, the mechanical con... In order to solve the problem of surrounding rock control in soft coal seam roadway, taking the centralized return airway of No. 2 coal seam in Liangdu Coal Industry as the research background, the mechanical conditions of roadway surrounding rock were analyzed by means of field investigation, rock mechanics experiment and numerical simulation. The design principles of roadway support in soft coal seam were put forward: high strength anchor cable support, high preload support and high stiffness support. The bearing capacity of surrounding rock was strengthened by anchor cable support, and the deformation and failure of surrounding rock were effectively controlled. Through the numerical simulation method, the deformation and plastic failure range of roadwaysunder different support schemes are compared and analyzed. The support scheme of centralized transportation roadway is studied and determined, and the field test is carried out, which effectively controls the deformation of surrounding rock of roadway in weak coal seam. 展开更多
关键词 roadway Support High Preload High Strength Bolt Support Support Design
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Anchorage performance of large-diameter FRP bolts and their application in large deformation roadway
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作者 Jun Han Zuoqing Bi +2 位作者 Bing Liang Chen Cao Shuangwen Ma 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第8期1037-1043,共7页
In underground coal mines, fibre reinforced polymer(FRP) bolt is ideal for mined rib reinforcements as it can prevent gas explosions caused by shearer frictional spark. With increasing mining depth, small diameter FRP... In underground coal mines, fibre reinforced polymer(FRP) bolt is ideal for mined rib reinforcements as it can prevent gas explosions caused by shearer frictional spark. With increasing mining depth, small diameter FRP bolts used in shallow underground mining cannot fulfil the rib support requirements. Under the engineering background of deep underground shortwall mining in Wudong coal mine, this paper systematically studies Φ27 mm FRP bolt support for large deformation coal rib. Specimens with a fan-shaped cross-section were used to enable the tensile testing of the bolt rod, the measured average tensile strength of the studied FRP bolt was(486.1 ± 9.6) MPa with a maximum elongation of 5.7%±0.6%.The shear strength of the bolt was measured as approximately 258 MPa using a self-made double shear testing apparatus. Based on the equivalent radial stiffness principle, a laboratory short encapsulation pullout test(SEPT) method for rib bolting has been developed undertaken consideration of the mechanical properties of the coal seam. Results showed that the average peak anchorage forces of the Φ27 mm FRP bolt and Φ20 mm steel rebar bolt were 108.4 and 66.4 k N, respectively, which were agreed with the theoretical calculations and field measurements. Based on theoretical analysis of the loading states of the bolt under site conditions, bolting method of full-length resin grouting was adopted to offset the weaknesses of the FRP bolt. Numerical method was employed to compare the bolting effect using Φ27 mm FRP bolts and steel rebar bolts. Large diameter FRP bolting was determined as the optimum rib support scheme to increase the productivity of the coal mine and to enhance the ground control capability for+425 level mining roadways. This study provides the laboratory testing design and theoretical prediction of large diameter FRP bolts used for rib support in large deformation roadways. 展开更多
关键词 FRP bolt Laboratory SEPT Tensile strength Double shear testing Mined rib support Large deformation roadway
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Comparison of large deformation failure control method in a deep gob-side roadway: A theoretical analysis and field investigation
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作者 WANG Jiong LIU Peng +2 位作者 HE Man-chao LIU Yi-peng DU Chang-xin 《Journal of Mountain Science》 SCIE CSCD 2023年第10期3084-3100,共17页
Under the dual influence of the mining disturbance of the previous working face and the advanced mining of the working face,the roadway is prone to large deformation,failure,and rockburst.Roadway stabilization has alw... Under the dual influence of the mining disturbance of the previous working face and the advanced mining of the working face,the roadway is prone to large deformation,failure,and rockburst.Roadway stabilization has always significantly influenced deep mining safety.In this article we used the research background of the large deformation failure roadway of Fa-er Coal Mine in Guizhou Province of China to propose two control methods:bolt-cable-mesh+concrete blocks+directional energy-gathering blasting(BCM-CBDE method)and 1st Generation-Negative Poisson’s Ratio(1G NPR)cable+directional energy-gathering blasting+dynamic pressure stage support(πgirder+single hydraulic prop+retractable U steel)(NPR-DEDP method).Meantime,we compared the validity of the large deformation failure control method in a deep gob-side roadway based on theoretical analysis,numerical simulations,and field experiments.The results show that directional energy-gathering blasting can weaken the pressure acting on the concrete blocks.However,the vertical stress of the surrounding rock of the roadway is still concentrated in the entity coal side and the concrete blocks,showing a’bimodal’distribution.BCM-CBDE method cannot effectively control the stability of the roadway.NPR-DEDP method removed the concrete blocks.It shows using the 1G NPR cable with periodic slipping-sticking characteristics can adapt to repeated mining disturbances.The peak value of the vertical stress of the roadway is reduced and transferred to the deep part of the surrounding rock mass,which promotes the collapse of the gangue in the goaf and fills the goaf.The pressure of the roadway roof is reduced,and the gob-side roadway is fundamentally protected.Meantime,the dynamic pressure stage support method withπgirder+single hydraulic prop+retractable U steel as the core effectively protects the roadway from dynamic pressure impact when the main roof is periodically broken.After the on-site implementation of NPR-DEDP method,the deformation of the roadway is reduced by more than 45%,and the deformation rate is reduced by more than 50%. 展开更多
关键词 Deep gob-side roadway Deformation failure control Roof structure mechanical model Stress field distribution Mining safety .Failure mode.
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Analysis on advanced transient EM detectability of coal mine roadway
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作者 LING Hong LIU Yunhe MA Xinpeng 《Global Geology》 2023年第3期177-188,共12页
The hidden water-bearing structures near the roadway tunnelling face are very likely to cause water seepage accidents in coal mines.Currently,transient electromagnetic(EM)technology has be-come an important method to ... The hidden water-bearing structures near the roadway tunnelling face are very likely to cause water seepage accidents in coal mines.Currently,transient electromagnetic(EM)technology has be-come an important method to detect water damage in advance of roadway excavation.In this paper,the time-domain finite element algorithm based on unstructured tetrahedron grids is used to accurate-ly simulate the geological body in front of the roadway excavation face and analyze its response.The authors detect the distance between the roadway excavation face and the low-resistivity water-bearing body,the resistivity difference between the low-resistivity body and surrounding rock,and the influence of the size of the low-resistivity body on the transient EM response.Furthermore,the common types of low-resistivity bodies in the roadway drivage process are used for modeling to analyze the attenuation of the detected EM response when there are low-resistivity bodies in front of the roadway.The research in this paper can help effectively detecting the water-bearing low-resistivity body in front of the roadway drivage and lay a foundation for reducing the risk of water seepage accidents. 展开更多
关键词 coal mine roadway transient EM time-domain finite-element advanced detection
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Traffic Incident Management Performance Measures: Ranking Agencies on Roadway Clearance Time
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作者 Maroa Mumtarin Skylar Knickerbocker +1 位作者 Theresa Litteral Jonathan S. Wood 《Journal of Transportation Technologies》 2023年第3期353-368,共16页
This study develops a procedure to rank agencies based on their incident responses using roadway clearance times for crashes. This analysis is not intended to grade agencies but to assist in identifying agencies requi... This study develops a procedure to rank agencies based on their incident responses using roadway clearance times for crashes. This analysis is not intended to grade agencies but to assist in identifying agencies requiring more training or resources for incident management. Previous NCHRP reports discussed usage of different factors including incident severity, roadway characteristics, number of lanes involved and time of incident separately for estimating the performance. However, it does not tell us how to incorporate all the factors at the same time. Thus, this study aims to account for multiple factors to ensure fair comparisons. This study used 149,174 crashes from Iowa that occurred from 2018 to 2021. A Tobit regression model was used to find the effect of different variables on roadway clearance time. Variables that cannot be controlled directly by agencies such as crash severity, roadway type, weather conditions, lighting conditions, etc., were included in the analysis as it helps to reduce bias in the ranking procedure. Then clearance time of each crash is normalized into a base condition using the regression coefficients. The normalization makes the process more efficient as the effect of uncontrollable factors has already been mitigated. Finally, the agencies were ranked by their average normalized roadway clearance time. This ranking process allows agencies to track their performance of previous crashes, can be used in identifying low performing agencies that could use additional resources and training, and can be used to identify high performing agencies to recognize for their efforts and performance. 展开更多
关键词 Traffic Incident Management roadway Clearance Time Performance Measures and Ranking Agency Performance Evaluation Tobit Regression Model
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相邻空区影响下三软巷道变形破坏规律与煤柱留设宽度研究
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作者 解盘石 林伟典 +4 位作者 张小明 张颖异 黄宝发 杨航 曾佑富 《煤炭工程》 北大核心 2024年第3期1-9,共9页
为了探究相邻空区影响下三软煤层巷道掘进时不同煤柱宽度下巷道围岩变形破坏规律,采用理论计算、数值模拟、物理相似模拟与现场实测相结合的研究方法,分析存在临空区后不同区段煤柱宽度下巷道围岩应力演化规律、塑性破坏范围以及位移分... 为了探究相邻空区影响下三软煤层巷道掘进时不同煤柱宽度下巷道围岩变形破坏规律,采用理论计算、数值模拟、物理相似模拟与现场实测相结合的研究方法,分析存在临空区后不同区段煤柱宽度下巷道围岩应力演化规律、塑性破坏范围以及位移分布特征。结果表明:临空区是造成巷道掘进后非对称破坏的主要原因,使煤柱主应力方向与垂向夹角增大,巷道两帮应力呈煤柱侧大于实体煤侧的非对称分布特征;三软巷道破坏形式以剪切破坏为主,破坏主体为两帮,随着煤柱宽度增大,主应力方向与垂向夹角减小,巷道围岩破坏程度降低,临空区对巷道不同位置的影响程度不同,巷道中部围岩破坏程度大于端头处且煤柱侧破坏程度大于实体煤侧;煤柱宽度增大对巷道围岩应力以及煤柱破坏的改善程度有限,现场结果显示当煤柱宽度为20 m时巷道正常维护满足需求。 展开更多
关键词 三软巷道 煤柱宽度 巷道失稳 相邻空区 非对称破坏
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深部巷道围岩裂隙注浆加固浆液扩散规律研究
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作者 肖同强 余子豪 +1 位作者 李怀珍 许磊 《河南理工大学学报(自然科学版)》 CAS 北大核心 2024年第1期16-24,共9页
目的为了解决深部巷道围岩裂隙注浆加固难题,方法采用现场矿压观测、数值模拟等方法,结果研究得到深部巷道围岩破坏特征:深部巷道呈现“顶、帮、底”全断面大变形现象,围岩破坏深度显著增加;深部巷道围岩由浅至深形成裂隙发育区、裂隙... 目的为了解决深部巷道围岩裂隙注浆加固难题,方法采用现场矿压观测、数值模拟等方法,结果研究得到深部巷道围岩破坏特征:深部巷道呈现“顶、帮、底”全断面大变形现象,围岩破坏深度显著增加;深部巷道围岩由浅至深形成裂隙发育区、裂隙扩展区和原生裂隙区,其中裂隙扩展区裂隙较小,注入难度较大。采用数值模拟方法,分析裂隙特征、注浆压力、浆液水灰比等因素对浆液扩散特征的影响规律,结果表明:裂隙开度对浆液扩散半径影响显著,而裂隙粗糙度的影响较小;对于裂隙开度较大的裂隙发育区,采用常规注浆压力;对于裂隙扩展区,裂隙开度较小(小于0.10 mm),应采用高于10 MPa的注浆压力;浆液扩散半径与注浆压力、水灰比呈正比,但对于深部微围岩裂隙而言,注浆压力存在临界点,不应盲目增大注浆压力,选取水灰比时,应综合考虑浆液扩散半径和浆液析水效应。结论对于注浆工程而言,选取浆液配比及注浆压力时,应考虑巷道开挖后围岩裂隙开度的发育状态。 展开更多
关键词 深部巷道 围岩裂隙 注浆加固 浆液扩散
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基于冲能吸能平衡效应的冲击地压巷道分级支护研究 被引量:1
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作者 高明仕 俞鑫 +2 位作者 徐东 贺永亮 赵世帆 《岩土力学》 EI CAS CSCD 北大核心 2024年第1期38-48,共11页
冲击地压是煤炭开采过程中发生的一种动力灾害,主要是由积聚在煤岩中的弹性变形能突然急剧释放造成的,约90%发生在巷道中。巷道冲击破坏不仅与冲击能量直接相关,还与冲击距离远近紧密相关,提出能距比的概念,即冲击震源释放能量与其至巷... 冲击地压是煤炭开采过程中发生的一种动力灾害,主要是由积聚在煤岩中的弹性变形能突然急剧释放造成的,约90%发生在巷道中。巷道冲击破坏不仅与冲击能量直接相关,还与冲击距离远近紧密相关,提出能距比的概念,即冲击震源释放能量与其至巷道距离的比值。根据冲击地压动静载叠加机制和冲能吸能平衡理论,综合考虑冲击震源能距比量级、巷道破坏程度、支护构件吸能、弱结构吸能等特性,建立了巷道围岩冲击矿震稳定性控制模型,分析了冲能、吸能的构成和计算过程,搭建了冲击地压能级与巷道支护强度之间的对应关系,确定了“四高锚网+”为主导技术的煤矿巷道防冲抗震支护体系。根据能距比量级大小,将冲击地压巷道支护安全可靠性分为P1~P4级别,分级对应采取不同支护强度的“四高锚网+”组合支护技术。“四高”锚网支护可对应能距比为102量级的无冲击巷道,“四高锚网+1”(O型钢棚、吸能防冲单元架、围岩弱结构)对应能距比为103量级的冲击地压,“四高锚网+2”对应能距比为104量级的冲击地压,“四高锚网+3”对应能距比为105量级的冲击地压,106及以上量级的冲击危险必须停产、撤人远场处理。结合工程实例进行了巷道防冲支护方案和参数设计,初步验证了理论研究成果的可行性和实用性。研究成果可为我国煤矿冲击地压巷道支护理论研究和工程实践提供一定的参考指导。 展开更多
关键词 冲击地压 巷道围岩控制 冲能吸能平衡 能距比 分级支护
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巷道围岩应力应变仿真系统设计与教学探索
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作者 庞冬冬 李传明 +3 位作者 庞大伟 陈中琪 贺凯 罗肖龙 《实验室研究与探索》 CAS 北大核心 2024年第4期80-83,93,共5页
为了获得采动条件下巷道围岩应力应变演化特征,通过复变函数换算结合工程实践经验,运用科学计算软件编程对巷道围岩受力模型进行求解,获得巷道围岩主应力和主应力集中系数分布规律。采用MATLAB对巷道受力模型进行模拟演算,获得工程开采... 为了获得采动条件下巷道围岩应力应变演化特征,通过复变函数换算结合工程实践经验,运用科学计算软件编程对巷道围岩受力模型进行求解,获得巷道围岩主应力和主应力集中系数分布规律。采用MATLAB对巷道受力模型进行模拟演算,获得工程开采参数与巷道围岩应力应变的关系规律,由此设计了一种采动影响下巷道围岩应力应变模拟仿真系统。该系统可对多种巷道断面进行计算和模拟,进而呈现出多种信息仿真演示,解决了以往软件适用巷道类型单一、应力求解不具体且结果呈现单一化缺点,可为回采巷道支护设计提供相应的理论依据,有利于矿山工程技术人员及实验室技术人员开展模拟仿真教学。 展开更多
关键词 巷道围岩 应力应变 模拟仿真 受力模型 开发设计
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大倾角煤层抗剪锚杆设计与测试
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作者 丁小敏 董昊福 +4 位作者 张玮 付慧见 刘冬亮 徐宝龙 刘玉德 《煤矿机械》 2024年第2期8-11,共4页
为了减少大倾角煤层斜梯形巷道变形破坏,设计了新型抗剪锚杆,分析了锚杆工作原理及锚杆参数。以东峡煤矿为工程背景,采用物理模拟、数值模拟和现场监测相结合的研究方法,对大倾角斜梯形巷道抗剪锚杆支护进行了研究。结果表明,在加载中,... 为了减少大倾角煤层斜梯形巷道变形破坏,设计了新型抗剪锚杆,分析了锚杆工作原理及锚杆参数。以东峡煤矿为工程背景,采用物理模拟、数值模拟和现场监测相结合的研究方法,对大倾角斜梯形巷道抗剪锚杆支护进行了研究。结果表明,在加载中,原支护模型在4.9 MPa即发生破坏,而抗剪锚杆支护模型在7 MPa发生破坏,原支护试验顶板下沉量较大,其变形量及变形速度远大于抗剪锚杆支护试验;抗剪锚杆能有效控制巷道顶板离层,离层量为21~129 mm,抗剪锚杆能够承受的极限破断载荷为155 kN,能有效控制深部围岩的变形。 展开更多
关键词 大倾角巷道 巷道支护 物理模拟 数值模拟 现场监测
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