检索结果-南通市图书馆

International Journal of Mining Science and Technology 2017年第5期27卷 819-823页

作者： Zha Wenhua Shi Hao Liu San Kang Changhao Key Laboratory of Safe and Effective Coal Mining School of Mining and Safety EngineeringAnhui University of Science&TechnologyMinistry of EducationHuainan 232001China

Gob-side entry driving can increase coal recovery ratio, and it is implied in many coal mines. Based on geological condition of 10416 working face tailentry in Yangliu Coal Mine, the surrounding rock deformation characteristics of gob-side entry driving with narrow coal pillar is analysed, reasonable size of coal pillar and reasonable roadway excavation time after mining are achieved. surrounding rock control technology and effective roadway side sealing technology are proposed and are taken into field practice. The results showed that a safer and more efficient mining of working face can be achieved. In addition, results of this paper also have important theoretical significance and valuable reference for surrounding rock control technology of gob-side entry driving with narrow coal pillar under special geological condition.

关键词： Narrow coal pillar Gob-side entry driving surrounding rock control Roadway side sealing technology

surrounding rock deformation and stress evolution in pre-driven longwall recovery rooms at the end of mining stage

在线全文

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2019年第4期6卷 536-546页

作者： Bonan Wang Faning Dang Wei Chao Yanping Miao Jun Li Fei Chen School of Civil Engineering and Architecture Xi'an University of TechnologyXi'an 710048ShaanxiPeople's Republic of China Shennan Hongliulin Mining Co Ltd of Shaanxi Coal Group Shenmu 719300ShaanxiPeople's Republic of China Shennan Zhangjiamao Mining Co Ltd of Shaanxi Coal Group Shenmu 719300ShaanxiPeople's Republic of China Shennan Ningtiaota Mining Co Ltd of Shaanxi Coal Group Shenmu 719300ShaanxiPeople's Republic of China

Two case studies were conducted in the Shennan mining area of Shaanxi Province,China to evaluate the surrounding rock deformation and stress evolution in pre-driven longwall recovery rooms· These studies mainly monitored the surrounding rock deformation and coal pillar stress in the recovery rooms of the N1206 panel of 2-2 coal seam at Ningtiaota Coal Mine and the 15205 panel of 5-2 coal seam at Hongliulin Coal *** monitoring results showed that the surrounding rock deformation of the main recovery room and the coal pillar stress in the N1206 and 15205 panels began to increase significantly when the face was 36 m and 42 m away from the terminal line,*** the face entered the main recovery room,the maximum roof-to-floor convergence in the N1206 and 15205 panels was 348.03 mm and 771.24 mm,respectively,and the coal pillar stresses increased more than 5 MPa and 7 MPa,*** addition,analysis of the periodic weighting data showed that the main roof break position of the N1206 and 15205 panels after the longwall face entered the main recovery room was-3.8 m and-8.2 m,*** research shows that when the main roof breaks above the coal pillar,the surrounding rock deformation of the main recovery room and the coal pillar stress increase *** last weighting is the key factor affecting the stability of the main recovery room and the coal pillar;main roof breaks at disadvantageous positions are the main cause of the support crushing accidents.

关键词： Pre-driven longwall recovery room surrounding rock deformation Stress evolution Periodic weighting

Systematic principles of surrounding rock control in longwall mining within thick coal seams

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2019年第1期29卷 65-71页

作者： Jiachen Wang Zhaohui Wang Faculty of Resources and Safety Engineering China University of Mining&TechnologyBeijing

Effective surrounding rock control is a prerequisite for realizing safe mining in underground coal *** the past three decades, longwall top-coal caving mining(LTCC) and single pass large height longwall mining(SPLL) found expanded usage in extracting thick coal seams in China. The two mining methods lead to large void space left behind the working face, which increases the difficulty in ground *** face failure is a common problem in both LTCC and SPLL mining. Such failure is conventionally attributed to low strength and high fracture intensity of the coal seam. However, the stiffness of main components included in the surrounding rock system also greatly influences longwall face ***, surrounding rock system is developed for LTCC and SPLL faces in this paper. The conditions for simultaneous balance of roof structure and longwall face are put forward by taking the stiffness of coal seam, roof strata and hydraulic support into account. The safety factor of the longwall face is defined as the ratio between the ultimate bearing capacity and actual load imposed on the coal *** influences provided by coal strength, coal stiffness, roof stiffness, and hydraulic support stiffness,as well as the movement of roof structure are analyzed. Finally, the key elements dominating longwall face stability are identified for improving surrounding rock control effectiveness in LTCC and SPLL faces.

关键词： Longwall top coal caving mining Single pass large height longwall mining surrounding rock system Longwall face stability

Stress distribution and surrounding rock control of mining near to the overlying coal pillar in the working face

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2019年第6期29卷 881-887页

作者： Rui Gao Bin Yu Xiangbin Meng Key Laboratory of Deep Coal Resource Mining School of MinesMinistry of Education of ChinaChina University of Mining&TechnologyXuzhou 221116China Datong Coal Mine Group Co.Ltd. Datong 037000China

The occurrence of overlying coal pillar(OCP)exerts a strong effect on the stress and strain distribution of the surrounding rock in the *** this paper,the stress distribution characteristics are analyzed via the numerical calculation with the account of OCP presence or *** addition,this study revealed the joint effect of side pressure relief area of the goaf and stress concentration in OCP on the final stress ***,the rules of abutment stress distribution affected by three influencing factors,namely horizontal-vertical distances between OCP and working face and buried depth of OCP,are *** functional model linking the peak stress of surrounding rock with the above influencing factors is *** field application of the above results proved that the rib spalling and deformation of a 2.95 m-high and 5.66 m-wide roadway could be efficiently controlled by rationally adjusting working states of the support,and adopting the hydraulic prop coordinated with the p type metal beam and anchor cable to strengthen the surrounding rock of working face and roadway,*** proposed measures are considered appropriate to satisfy the safe operation requirements.

关键词： Overlying coal pillar(OCP) Stress distribution Influencing factors surrounding rock control

Rock burst risk evaluation based on equivalent surrounding rock strength

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2019年第4期29卷 571-576页

作者： Jinglin Wen Husheng Li Fuxing Jiang Zhengxing Yu Haitao Ma Xiaolin Yang China Academy of Safety Science and Technology Beijing 100012China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China

On-site investigations consistently show that the rock burst inherent to coal seams varies greatly with coal seam *** this study,impact factors related to coal seam thickness and surrounding rock strength were analyzed and a corresponding rock burst risk assessment method was *** model reflects the influence of coal seam thickness on the stress distribution of surrounding rock at the *** on the roadway excavation range,a stress distribution model of surrounding roadway rock is established and the influence of coal seam thickness on rock burst risk is analyzed *** proposed rock burst risk assessment method is based on the equivalent surrounding rock strength and coal seam bursting *** proposed method was tested in a 3500 mining area to find that it yields rock burst risk assessment results as per coal seam thickness that are in accordance with real-world *** results presented here suggest that coal seam thickness is a crucial factor in effective rock burst risk assessment.

关键词： Mining engineering Coal seam thickness Rock burst risk Equivalent surrounding rock strength Bursting liability

Forced Vibration of the Non-Homogeneously Pre-Stressed System Consisting of the Hollow Cylinder and surrounding Medium

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2019年第10期121卷 315-348页

作者： Surkay D.Akbarov Emin T.Bagirov Department of Mechanical Engineering Yildiz Technical UniversityYildiz Campus34349BesiktasIstanbulTurkey Institute of Mathematics and Mechanics of the National Academy of Sciences of Azerbaijan 37041BakuAzerbaijan.

The paper deals with the study of the influence of the non-homogeneous prestresses in the system consisting of the hollow cylinder and surrounding elastic medium on the frequency response of this system caused by the time-harmonic ring load acting in the interior of the *** axisymmetric problem is considered and it is assumed that in the initial state,the system is compressed in the radial direction with homogeneously distributed static forces as a result of which,non-homogeneous pre-stresses(or initial stresses)appear in *** is also assumed that after these pre-stresses appear in the interior of the cylinder,the point-located(with respect to the axial coordinate directed along the cylinder’s central axis)additional time-harmonic ring load ***,it is required to determine how the pre-stresses influence the frequency response of the system to the noted additional time-harmonic *** influence,which is the non-linear effect,is studied within the scope of the so-called three-dimensional linearized equations and relations of the theory of elastic waves in pre-stressed *** solution to the corresponding boundary value problems is found by employing the discrete analytical solution method and numerical results on the influence of the pre-stresses on the frequency response of the interface stresses which appear as a result of the action of the additional time-harmonic forces,are presented and *** particular,it is established that the pre-stresses mentioned above cause to decrease the magnitude of the interface dynamic stresses appearing as a result of the additional time-harmonic loading.

关键词： Non-linear effect inhomogeneous initial stresses frequency response timeharmonic ring load hollow cylinder surrounding medium

Macro/meso failure behavior of surrounding rock in deep roadway and its control technology

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2019年第3期6卷 301-319页

作者： Jianping Zuo Jintao Wang Yunqian Jiang School of Mechanics and Civil Engineering China University of Mining and Technology Beijing 100083 China State Key Laboratory of Coal Resources and Safe Mining China University of Mining and Technology Beijing 100083 China

Engineering disasters occur frequently and violently with the increase in mining depth, which is mostly due to insufficient study on the failure mechanism of the deep rock mass. In this paper, theoretical and experimental researches on the failure behaviors and deformation control of deep surrounding rock in recent years were reviewed. Macro/meso failure mechanism of deep rock or coal-rock combined body under different loading conditions have been systematically investigated. Stress gradient failure theory of surrounding rock, uniform strength support in the deep roadway, and the analogous hyperbola movement model of overlying strata were preliminary established and a combined grouting control technology for surface and underground was proposed. Abovementioned achievements are expected to offer theoretical bases and technical supports for the exploitation of China's deep mineral resources in the future.

关键词： Failure mechanics Deep mining Control of surrounding rock Failure mechanism

Non-contact monitoring and analysis system for tunnel surrounding rock deformation of underground engineering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2005年第S1期15卷 96-99页

作者： YANG Song-lin, WANG Bin, JI Sheng-yue, LIU Wei-ning, SHI Hong-yun (Beijing Jiaotong University, Beijing 100044, China) Beijing Jiaotong Univ Beijing 100044 Peoples R China

It is very important to monitor surrounding rock deformation in tunnel construction. The principle, function, development and application of the system composed of a total station and computer for monitoring and analyzing surrounding rock deformation were discussed. The new methods of two free station of 3D measurement and its mathematic adjustment mode were presented. The development of software for total station on-board and post for computer were also described. Without centering it and measuring its height, the total station controlled by the software on-board can fulfill the whole measurements to target points. Monitoring data can be processed by the post software and results of regression analysis, forecasting information of the tunnel surrounding rock deformation can be provided in time. The practical use shows that this system is practicable, highly accurate and efficient. It satisfies the needs of safety and information construction in tunnel construction of underground engineering.

关键词： tunnel construction deformation of surrounding rock total station non-contact monitoring data processing and analysis

The diurnal and seasonal characteristics of urban heat island variation in Beijing city and surrounding areas and impact factors based on remote sensing satellite data

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2005年第z2期48卷 220-229页

作者： ZHANG Jiahua, HOU Yingyu, LI Guicai, YAN Hao YANG Limin & YAO Fengmei The Chinese Academy of Meteorological Sciences, Beijing 100081, China The National Meteorological Center, Beijing 100081, China The National Satellite Meteorological Center, Beijing 100081, China Joint Laboratory for Geoinformation Science, The Chinese University of Hong Kong, Hong Kong, China Department of Geosciences, Graduate School of Chinese Academy of Sciences, Beijing 100039, China The Chinese Academy of Meteorological Sciences Beijing 100081 China The National Meteorological Center Beijing 100081 China The National Satellite Meteorological Center Beijing 100081 China Joint Laboratory for Geoinformation Science The Chinese University of Hong Kong Hong Kong China

Based on the land surface temperature (LST), the land cover classification map,vegetation coverage, and surface evapotranspiration derived from EOS-MODIS satellite data, and by the use of GIS spatial analytic technique and multivariate statistical analysis method, the urban heat island (UHI) spatial distribution of the diurnal and seasonal variabilities and its driving forces are studied in Beijing city and surrounding areas in 2001. The relationships among UHI distribution and landcover categories, topographic factor, vegetation greenness, and surface evapotranspiration are analyzed. The results indicate that: (i) The significant UHI occur in Beijing city areas in the four seasons due to high heat capacity and multi-reflection of compression building, as well as with special topographic features of its three sides surrounded by mountains,especially in the summer. The UHI spatial distribution is corresponding with the urban geometry structure profile. The LST difference is approximately 4-6℃ between Beijing city and suburb areas, comparatively is 8- 10℃ between Beijing city area and outer suburb area in northwestern regions. (ii) The UHI distribution and intensity in daytime are different from nighttime in Beijing city area, the nighttime UHI is obvious. However, in the daytime, the significant UHI mainly appears in the summer, the autumn takes second place, and the UHI in the winter and the spring seem not obvious. The surface evapotranspiration in suburb areas is larger than that in urban areas in the summer, and high latent heat exchange is evident, which leads to LST difference between city area and suburb area. (iii) The reflection of surface landcover categories is sensitive to the UHI, the correlation between vegetation greenness and UHI shows obviously *** scatterplot shows that there is the negative correlation between NDVI and LST (R2 = 0.6481).The results demonstrate that the vegetation greenness is an important factor for reducing the UHI,and la

关键词： urban heat island, vegetation cover, LST, MODIS, Beijing city and surrounding areas.

Deformation prediction model of surrounding rock based on GA-LSSVM-markov

在线全文

学校读者我要写书评

暂无评论

Natural Science 2012年第2期4卷 85-90页

作者： Duo-Dian Wang Guo-Qing Qiu Wen-Bin Xie Yue Wang Engineering Institute of Corps of Engineers PLA University of Science &Technology Nanjing China

Command protection engineering is the important component of national protection engineering system. To raise the level of its construction, a deformation prediction model is given based on Genetic Algorithm (GA), Least Square Support Vector Machines (LSSVM) and markov theory. Genetic algorithm is used to improve the parameter of LSSVM. Markov predict method is used to improve the precision of the prediction model. Finally, be used to a certain command protection engineering, the accuracy of the algorithm is improved obviously. The model is proved to be credible and precise.

关键词： Genetic Algorithm(GA) Least Square Support Vector Machines(LSSVM) Markov Evaluation surrounding Rock Command Protection Engineering