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Strength and deformation behaviors of bedded rock mass under bolt reinforcement

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International Journal of Mining Science and Technology 2018年第4期28卷 591-597页

作者： Wenxin Zhu Hongwen Jing Lijun Yang Bing Pan haijian su State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and Technology School of Traffic and Civil Engineering Shandong Jiaotong University

The mechanism of bolt support is an important topic in mining engineering and slope treatment. The artificial material and loading system were self-developed to study the influence of bedding cohesion and bolt number on the anchoring behavior of bedded rock mass. The results show that, both peak strength and elasticity modulus increase gradually with the increase of bedding cohesion and bolt number. The axial stress–strain curve of bedded rock mass under the reinforcement of bolts presents the features of strain-softening and secondary strengthening. Finally, anchoring behavior of bedded rock mass with different bolt numbers was simulated by using FLAC3 D numerical program and the results were compared with the experimental results. This study can provide certain bases to the stability control and support design of bedded rock mass in roadway.

关键词： Bedded rock mass Anchoring behavior Peak strength Bedding cohesion Secondary strengthening

Fracture evolution characteristics of sandstone containing double fissures and a single circular hole under uniaxial compression

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International Journal of Mining Science and Technology 2017年第3期27卷 499-505页

作者： Chen Minliang Jing Hongwen Ma Xiujun su haijian Du Mingrui Zhu Tantan State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining & Technology Xuzhou 221116 China Tianjin Traffic Science Research Institute Tianjin 300074 China JSTI GROUP Nanfing 210000 China

The uniaxial compression experiments on the sandstone samples containing double fissures and a single circular hole were carried out by using electro-hydraulic servo universal testing machine to investigate the effect of rock bridge angle β and fissure angle α on mechanical properties and evolution characteristics of *** results show that the peak strength,peak strain and elastic modulus of defected specimens decrease comparing with those for intact sample,and show a decreased trend firstly and then increase with β changing from 0° to 90°.The peak strength and elastic modulus achieve the minimum value as the rock bridge angle is 60°,while the peak strain reaches the minimum value with the rock bridge angle of 45°.The crack initiation of tested rock samples occurs firstly in stress concentration areas at tips of prefabricated fissures under uniaxial compression,and then propagates constantly and coalescences with the prefabricated *** secondary cracks initiate and propagate as well until buckling failure *** rock bridge angle has a great influence on crack initiation,coalescence,final failure mode,crack initiation stress and transfixion *** peak strength varies significantly,while the elastic modulus and peak strain change slightly,and the failure modes are also different due to the influence of fissure angle.

关键词： Double fissures A single circular hole Strength characteristics Crack propagation Failure mode

Failure mechanism and stability control of a large section of very soft roadway surrounding rock shear slip

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International Journal of Mining Science and Technology 2013年第1期23卷 127-134页

作者： Meng Bo Jing Hongwen Chen Kunfu su haijian State Key Laboratory of Geomechanics and Deep Underground Engineering China University of Mining & Technology School of Mechanics and Civil Engineering China University of Mining & Technology

The measured data and simulation test phenomenon of surrounding rock deformation and failure at the project site indicate that shear failure which firstly occurs in surrounding rock, block slip and second shear failure are the root cause of deformation and damage of supporting structure of the surrounding rock at a large scale. We derived limit load of surrounding rock shear slip failure and reasonable support resistance of given load by means of shear slip line field theory, discussed the main factors which influence the limit load of surrounding rock. Shear slip line field and limit load of circular tunnel surrounding rock were obtained by means of physical simulation test, which agreed well with the theoretical analysis results. Based on the theoretical analysis and physical simulation test, the cause deformation and failure at large scale of Xinshanghai No. 1 coal mine big section ingate was analyzed, and the shear failure resistance and block slip in surrounding rock were proposed as the core technical supporting ideas. Proper range of supporting resistance which came from calculation was suggested. The support scheme which is mainly composed of large grouting anchor, sprayed anchor net support technique and full-face grille concrete finally ended the dilemma of repeated failure and mending of ingate and created critical conditions for smooth production in the coal mine.

关键词： Rock mechanics surrounding rock Shear and slip Shear and slip resistance Limit load

Strength and deformation behaviors of veined marble specimens after vacuum heat treatment under conventional triaxial compression

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Acta Mechanica Sinica 2017年第5期33卷 886-898页

作者： haijian su Hongwen Jing Qian Yin Liyuan Yu Yingchao Wang Xingjie Wu State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and Technology

The mechanical behaviors of rocks affected by high temperature and stress are generally believed to be significant for the stability of certain projects involving rocks, such as nuclear waste storage and geothermal resource exploitation. In this paper, veined marble specimens were treated to high temperature treatment and then used in conventional triaxial compression tests to investigate the effect of temperature, confining pressure, and vein angle on strength and deformation behaviors. The results show that the strength and deformation parameters of the veined marble specimens changed with the temperature, presenting a critical temperature of 600 . The triaxial compression strength of a horizontal vein () is obviously larger than that of a vertical vein (). The triaxial compression strength, elasticity modulus, and secant modulus have an approximately linear relation to the confining pressure. Finally, Mohr-Coulomb and Hoek-Brown criteria were respectively used to analyze the effect of confining pressure on triaxial compression strength.

关键词： Veined marble Conventional triaxial compression High temperature Vein angle Hoek-Brown criterion

Effect of the mineral spatial distribution heterogeneity on the tensile strength of granite:Insights from PFC3D-GBM numerical analysis

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第5期15卷 1144-1160页

作者： Tao Zhang Liyuan Yu Yuxuan Peng Hongwen Jing haijian su Jiangbo Wei State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou221116China College of Geology and Environment Xi’an University of Science and TechnologyXi’an710054China

The mechanical characteristics of crystalline rocks are affected by the heterogeneity of the spatial distribution of *** this paper,a novel three-dimensional(3D)grain-based model(GBM)based on particle flow code(PFC),***3D-GBM,is *** model can accomplish the grouping of mineral grains at the 3D scale and then filling ***,the effect of the position distribution,geometric size,and volume composite of mineral grains on the cracking behaviour and macroscopic properties of granite are examined by conducting Brazilian splitting *** numerical results show that when an external load is applied to a sample,force chains will form around each contact,and the orientation distribution of the force chains is uniform,which is independent of the external load ***,the number of high-strength force chains is proportional to the external load level,and the main orientation distribution is consistent with the external loading *** main orientation of the cracks is vertical to that of the high-strength force *** geometric size of the mineral grains controls the mechanical *** the average grain size increases,the number of transgranular contacts with higher bonding strength in the region connecting both loading points *** number of high-strength force chains increases,leading to an increase in the stress concentration value required for the macroscopic failure of the *** to the highest bonding strength,the generation of transgranular cracks in quartz requires a higher concentrated stress *** increasing volume composition of quartz,the number of transgranular cracks in quartz distributed in the region connecting both loading points increases,which requires many high-strength force *** load level rises,leading to an increase in the tensile strength of the numerical sample.

关键词： Rock mechanics Tensile strength Spatial distribution of minerals Three-dimensional(3D)grain-based model (GBM) Transgranular contact

Physical and mechanical properties of sandstone containing a single fissure after exposure to high temperatures

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International Journal of Mining Science and Technology 2016年第2期26卷 319-325页

作者： Zhu Tantan Jing Hongwen su haijian Yin Qian Du Mingrui Han Guansheng State Key Laboratory for Geomechanics & Deep Underground Engineering China University of Mining & Technology

In order to investigate the physical and mechanical properties of sandstone containing fissures after exposure to high temperatures,fissures with different angles α were prefabricated in the plate sandstone samples,and the processed samples were then heated at 5 different *** uniaxial compression was conducted to analyze the change rules of physical properties of sandstone after exposure to high temperature,and the deformation,strength and failure characteristics of sandstone containing *** results show that,with increasing temperature,the volume of sandstone increases gradually while the quality and density decrease gradually,and the color of sandstone remains basically unchanged while the brightness increases markedly when the temperature is higher than 585 ℃;the peak strength of sandstone containing fissures first decreases then increases when the temperature is between 25℃and 400℃.The peak strain of sandstone containing fissures increases gradually while the average modulus decreases gradually with increasing temperature,and the mechanical properties of sandstone show obvious deterioration after 400 ℃.The peak strain of sandstone containing fissures increases gradually while the average modulus decreases gradually with increasing temperature;with increasing angle αof the fissure,the evolution characteristics of the macro-mechanical parameters of sandstone are closely related to the their own mechanical *** the temperature is 800 ℃,the correlation between the peak strength and average modulus of sandstone and the angle α of the fissure is obviously *** failure modes of sandstone containing fissures after high temperature exposure are of three different kinds including:tensile crack failure,tensile and shear cracks mixed failure,and shear crack *** and shear crack mixed failure occur mainly at low temperatures and small angles;tensile crack failure occurs at high temperatures and large angles.

关键词： High temperature Sandstone containing fissure Strength characteristics Deformation characteristics Evolution law

Visualization and early warning analysis of damage degree of surrounding rock mass in underground powerhouse

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International Journal of Mining Science and Technology 2023年第6期33卷 717-731页

作者： Yuepeng sun haijian su Peiwei Xiao Peng Li Biao Li Xiang Zhou Kaiqi Bian Nuwen Xu State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China Dadu River Hydropower Development Company LTDChengdu 610016China School of Geoscience and Technology Southwest Petroleum UniversityChengdu 610500China

Based on the underground powerhouse of Shuangjiangkou hydropower station,Octree theory is adopted to define the indices of the microseismic(MS)spatial aggregation degree and the deviation values of MS count and *** relationship between the MS multiple parameters and surrounding rock mass instability is established from three aspects:time,space,and *** by the center frequency of the signal evolution characteristics,A fuzzy comprehensive evaluation model and the evolution trend of the MS event center frequency are constructed to quantitatively describe the early warning state of the surrounding rock mass *** results show that the multilevel tree structure and voxels generated based on the Octree theory fit relatively well with the set of MS points in threedimensional *** fuzzy comprehensive evaluation model based on MS spatial aggregation and MS count and energy deviation values enables three-dimensional visualization of the potential damage area and damage extent of the surrounding rock *** warning time and potential damage zone quantified are highly consistent with the characteristics of MS precursors,with wide recognition and field investigation results,which fully validate the rationality and applicability of the proposed *** findings can provide references for the early warning of surrounding rock mass instability in similar underground engineering.

关键词： Underground powerhouse MS monitoring Early warning Visualization

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论计算机软件产业行政保护的立法不足与完善

中国科技论坛 2009年第8期 54-58页

作者：苏海健山东工商学院山东烟台264005

计算机软件行政保护是一种全面保护。我国目前关于计算机软件的行政保护已有较多立法,但仍存在立法层次低、不规范,对计算机软件知识产权的行政保护方式单一、范围狭窄,扶持软件产业的行政措施不完善等诸多问题。为解决这些问题,应当建... 详细信息

计算机软件行政保护是一种全面保护。我国目前关于计算机软件的行政保护已有较多立法,但仍存在立法层次低、不规范,对计算机软件知识产权的行政保护方式单一、范围狭窄,扶持软件产业的行政措施不完善等诸多问题。为解决这些问题,应当建立完善的法律体系,制定《信息产业科技促进法》和《计算机软件保护法》,完善计算机软件著作权侵权行政处罚的法律条款,并对扶持计算机软件产业的行政措施进一步完善。

关键词：计算机软件行政保护立法不足完善

椭圆形孔洞对砂岩试样强度及变形特征影响研究

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采矿与安全工程学报 2017年第1期34卷 141-147页

作者：杜明瑞靖洪文苏海健中国矿业大学深部岩土力学与地下工程国家重点实验室江苏徐州221116

通过在板状砂岩内预制单一椭圆形孔洞,并利用DDL500型岩石力学伺服试验系统进行单轴压缩试验,考察了椭圆形孔洞长轴与轴向荷载间夹角α对砂岩试样强度及变形特征的影响规律。研究结果表明:含椭圆形孔洞砂岩试样的峰值强度随α角的增大... 详细信息

通过在板状砂岩内预制单一椭圆形孔洞,并利用DDL500型岩石力学伺服试验系统进行单轴压缩试验,考察了椭圆形孔洞长轴与轴向荷载间夹角α对砂岩试样强度及变形特征的影响规律。研究结果表明:含椭圆形孔洞砂岩试样的峰值强度随α角的增大呈现先减小后增大然后又降低的变化规律,在α为60°时降至最低;脆性岩石峰值强度随α角的整体变化规律与随单一裂隙倾角的变化规律类似,但由于2种缺陷几何形态上的差异性,其具体变化又稍有不同;随着α角从0°变化到90°,含椭圆形孔洞砂岩试样最终破坏模式可分为剪切破坏、拉剪混合破坏和张拉破坏3种。

关键词：砂岩椭圆形孔洞长轴倾角峰值强度破坏模式