Risk evaluation of rock burst through theory of static and dynamic stresses superposition

Rock burst is one of the most catastrophic dynamic hazards in coal mining. A static and dynamic stresses superposition-based(SDSS-based) risk evaluation method of rock burst was proposed to pre-evaluate rock burst risk. Theoretical basis of this method is the stress criterion incurring rock burst and rock burst risk is evaluated according to the closeness degree of the total stress(due to the superposition of static stress in the coal and dynamic stress induced by tremors) with the critical stress. In addition, risk evaluation criterion of rock burst was established by defining the "Satisfaction Degree" of static stress. Furthermore,the method was used to pre-evaluate rock burst risk degree and prejudge endangered area of an insular longwall face in Nanshan Coal Mine in China. Results show that rock burst risk is moderate at advance extent of 97 m, strong at advance extent of 97-131 m,and extremely strong(i.e. inevitable to occur) when advance extent exceeds 131 m(mining is prohibited in this case). The section of two gateways whose floor abuts 15-3 coal seam is a susceptible area prone to rock burst. Evaluation results were further compared with rock bursts and tremors detected by microseismic monitoring. Comparison results indicate that evaluation results are consistent with microseismic monitoring, which proves the method’s feasibility.     

坚硬顶板孤岛煤柱工作面冲击特征及机制分析

利用微震监测及现场冲击记录,对冲击震源、能量、显现区、显现范围及显现形式等进行定位与统计分析,总结冲击特征。通过理论建模与计算,从围岩体结构和应力状态2方面分析孤岛煤柱冲击机制。研究表明:60 m厚基本顶不破断及临空区覆岩"二次"运动使冲击震源均分布在临空区及其边沿;随孤岛面推进,煤体静载应力峰值逐渐增高并接近冲击临界应力,高静载应力与动载应力叠加达到并超过冲击临界应力使冲击频发;两巷靠近设计停采线部分为静载应力峰值区,该段巷道底板距15-3煤0~1 m,使该段巷道成为重复冲击显现区;机道应力高于风道,使机道显现次数多于风道,分别为6次和3次;巷道底板无支护,接近15-3煤,使显现形式主要为底鼓。该分析方法与思路为类似条件下的冲击治理提供借鉴。     

机器人仿真及其自动化研究进展

本文首先对机器人机器应用领域进行全面的介绍,并且通过分析国内外机器人目前的发展以及分析了国内外机器人仿真的发展及其特点,并展望了国内外机器人仿真技术的发展趋势.同时介绍了机器人自动化控制系统的特点,最后提出了机器人自动化未来的发展研究工作.     

岩石类材料松弛特性研究现状分析

深井软岩巷道支护是国内外研究的重点和难点,深井软岩巷道围岩变形的重要特点是流变性,松弛特性是岩石流变性的重要方面,但是少有研究。基于软岩巷道比例大,支护难等实际问题,加强对岩石松弛特性的研究,可以为深井软岩巷道支护研究提供理论依据。这将直接关系到井巷工程的经济性、可靠性和安全性。本研究对岩石松弛特性国内外研究现状进行了分析与评价,同时提出岩石松弛特性试验研究方法。     

薄煤层动静组合诱发冲击地压的机制

理论分析了动静组合诱发冲击地压的应力条件和能量转化过程,揭示了动静组合诱发冲击地压机制,数值计算分析了工作面应力分布特征与煤厚之间的关系,采用微震监测数据分析了卸压爆破产生的应力波传播规律,并分析研究了薄煤层动静载特征及诱发冲击地压过程。结果表明:薄煤层工作面应力集中程度较厚煤层高,峰值应力区距离煤壁较近,应力梯度较大;采动动载直接与高应力叠加,且开采导致的应力降以及单位体积煤体释放的弹性变形能远高于厚煤层,在动静组合作用下,薄煤层工作面易于达到动静组合诱发冲击地压的应力和能量条件,显著符合动静组合诱冲机制。最后基于动静载组合诱发薄煤层冲击地压的机制,探讨了薄煤层冲击地压防治原则和技术方法。     

急倾斜煤层的开采分析

介绍了急倾斜煤层开采的现状,通过分析急倾斜煤层中可能出现的瓦斯问题、急倾斜煤层开采后岩层的移动以及急倾斜煤层开采分析等问题,论证了煤层的开采是一个综合性较强、影响和制约因素很多的复杂系统。开采急倾斜特厚煤层时利用高效安全的机械化采煤方法,在煤层厚度较大的情况下,可以实现开采方法工效高、工艺简单、掘进巷道少、吨煤费用低等优点。     

人居环境与通风

1人居环境 人居环境应包括自然环境（包括生态环境、气候环境、物理环境等）和人文环境（包括艺术环境、社会环境和文化环境等）两个方面。在进行规划与设计中,要求把这两方面的环境和谐的协调好,以达到居民所要的生活舒适、工作便利、邻里和睦、身心健康、环境美化的目的。     

矿山压力及岩层控制原理

由于矿山开采活动的影响,在硐室周围岩体中形成的和作用在巷硐支护物上的力定义为矿山压力.在矿山压力的作用下,会引起各种力学现象,如岩体变形、破坏、塌落、支护物的变形破坏折损等,以及在岩体中产生的动力现象这些矿山压力显现都将严重影响矿山企业的采掘活动和经济效益.     

不同应变率下岩石破裂与声发射响应特征研究

为揭示冲击倾向性砂岩在不同应变率条件下的损伤演化规律,基于MTS岩石力学试验系统与PAC声发射信号采集系统,试验研究了不同单轴应变率作用下岩石损伤演化与声发射参量响应特征。研究表明,随着加载应变率增加,岩样极限强度明显提升,峰值强度对应应变值整体降低,达到峰值强度所需时间随应变率呈幂函数减少。应变率与AE累计撞击数、事件数、振铃数之间具有显著的负幂函数关系;相反,应变率越高,微裂隙在发育、扩展过程中所释放的AE平均能量越高。     

Mechanical genesis of Henan（China） Yima thrust nappe structure

Considering the serious coal and rock dynamic disasters around the main slip plane called F16 in the coal mining area） of Henan Yima（China） thrust nappe structure,the mechanical genesis of the Yima thrust nappe structure was studied comprehensively using geomechanics,fault mechanics,elastic mechanics,and Coulomb＇s law of friction.First,using the centrifugal inertia force of Earth＇s rotation as a source,a mechanical model of N-S compression superimposed with W-E reverse torsion was established to explain the formation of the early Yima coal basin and Jurassic Yima Group coal measures.Second,an equation for the ultimate stress in the forming stage of F16 was derived using the plastic slip-line field theory and the parabolic Mohr failure criterion.Moreover,the distribution of ultimate stress and the geometric characteristics of the fault profile were obtained using the field model parameters.Finally,the stress field of F16 and the mechanical genesis of the large-scale reverse thrust sheet were discussed based on elastic mechanics theory and Coulomb＇s law of friction.The results show that the tectonic framework of the early Yima coal basin and the formation pattern of Jurassic Yima Group coal measures given by the model are consistent with the in-situ explorations.The geometric characteristics of the fault profile obtained by numerical calculation can better reflect the shape of F16 in its forming stage,and the mechanical genesis of the large-scale reverse thrust sheet also concurred with the field situations.Thus,this work can provide a foundation for further studies on the genesis of the thrust nappe structure,the mechanism of rock bursts induced by F16,and the characteristics of the residual stress field in the Yima mining area.