Characteristics of mining tremors within the near-wave field zone     

Józef Dubiński  Grzegorz Mutke 《Pure and Applied Geophysics》1996,147(2):249-261

Mining in the Upper Silesian Coal Basin, Poland, induces tremors with magnitudes ranging up to 4.3. The recordings of mining tremors from the near-wave fiel and the far-wave field show different characteristics of ground motion.Knowledge of these characrteristics, has an enormous practical importance when solving the problems of resistance of underground workings against seismic impacts. The near-wave field is characterized by a domination of the high frequency components of motion, and the seismograms often are a single pulse Geomechanical interpretation of them leads to the conclusion that this pulse corresponds to a single exciting force. This fact is also reflected in the rockbursts: the potentially damaging ground motion which is restricted to the seismic source region.The seismometric data have shown that the peak particle velocities from a hypocentral distance of 200–300 m, resulted in more than 3 cm/s. The peak ground velocities appear to be dependent on stress drop , and peak particle velocities reaching 5 m/s may occur. The computational example proves that in a thick coal seam the pulse with the stress =1.8 MPa from the tremor at the short source distance can generate the rockburst.  相似文献   

爆破对岩爆产生作用的初步探讨   总被引：2，自引：0，他引：2  

谢勇谋  李天斌 《中国地质灾害与防治学报》2004,15(1):61-64

几个典型工程实例表明，岩爆发生的控制性因素主要是应力与岩性的关系，开挖爆破对岩爆的发生起着某种重要的作用，但这种作用一直未得到充分地认识。文章分析了开挖爆破产生的应力波在围岩中的传播及对围岩的影响：爆破产生的P波和Rayleigh波将分别在围岩中形成垂直和平行于围岩表面的拉张破裂面，这些破裂面可能是微观的，也可能是宏观的，它们为岩爆的发生提供了物质基础。文章最后通过岩爆实例及深井稳定性问题指出：开挖爆破不仅是岩爆的诱发性因素，在某条件下而且是一种控制性因素。  相似文献   

地下水封石洞油库地质灾害危险性评估——以山东某地下水封石洞油库工程为例     

陈奇  武强  李俊彦 《中国地质灾害与防治学报》2006,17(4):138-141,148

根据地下水封石洞油库的工程特点,分析了此类工程建设场地地质灾害类型。列举了工程场地可能存在的现状地质灾害、施工期地质灾害和运营期地质灾害。认为该类工程的地质灾害危险性评估应更关注地下地质灾害,尤其是岩爆灾害。以某地下水封石洞油库实际工程为例,说明岩爆灾害宏观预测评估应针对岩性和地应力两个主要因素。探讨了地质灾害预测评估的可靠性问题,指出预测评估的可靠性基于分析思路的正确和预测指标的合理选取。  相似文献   

Design criteria for roadway supports to resist dynamic loads     

Antoni Kidybiński 《Geotechnical and Geological Engineering》1986,4(2):91-109

Summary Conditions under which dynamic loads occur in mines are briefly described and the special vulnerability of roadways in coal mines to fail under dynamic load is considered. A method for assessment of shock load energy anticipated is proposed, based on the volume of rock and the velocity of rock particles induced by rapid rock failure and/or seismic tremors. Case examples from Upper Silesian coal mines are given and the safety factor of steel supports against the shock energy from rockbursts is discussed. The shock energy damping ability of various parts of steel supports and support systems is calculated as a basis for rational support design. Results of six mine experiments where various types of roadway support were installed and then loaded dynamically by blasting within surrounding rocks are discussed.  相似文献   

地下洞室岩爆预测计算方法综述   总被引：4，自引：0，他引：4  

董志高  吴继敏  刘成君 《地质灾害与环境保护》2002,13(2):6-9,16

地下洞室岩爆的发生直接影响地下工程的施工和威胁施工人员的安全，因此，进行合理的岩爆预测就显得尤为重要。本文概括介绍了当前地下洞室岩爆预测的计算方法，并详细分析了计算方法的适用性和发展性，简要提出了在岩爆预测中要注意的几点建议。  相似文献   

深埋特长雪峰山公路隧道工程地质勘察技术研究     

王跃飞  李军  黄辉  胡惠华  丁国华  吴建宁 《中国地质灾害与防治学报》2008,19(4):96-100

雪峰山隧道为深埋特长隧道。在该隧道的勘察过程中运用了大量高新技术,并开展了科研工作,对隧道围岩特性、地质构造、地应力场及岩爆、涌水量、围岩稳定性等与隧道设计、施工密切相关的问题均作出了准确的判断和预测。本文论述了一些新的勘察技术及科研成果,这些勘探与评价技术对其它深埋特长隧道有较好的借鉴作用。  相似文献   

应力波作用下巷道层裂破坏的数值模拟研究   总被引：7，自引：1，他引：6  

雷光宇  卢爱红  茅献彪 《岩土力学》2005,26(9):1477-1480

采用LS-DYNA软件,对扰动应力波作用下巷帮围岩层裂破坏结构的形成过程、扰动应力波强度pmax对层裂结构形成的影响进行了有效的数值模拟,得到了一定巷道围岩应力状态下巷帮围岩层裂结构的形状、厚度等特征。结果表明：扰动应力波是形成巷帮层裂结构,继而诱发冲击矿压的重要因素;扰动应力波的强度决定了是否形成巷帮层裂结构及其层裂结构的范围大小。研究结果对揭示煤矿冲击矿压的诱发机理,及采取有效地防治技术具有重要意义  相似文献   

Strength of ensemble learning in multiclass classification of rockburst intensity     

Junfei Zhang  Yuhang Wang  Yuantian Sun  Guichen Li 《国际地质力学数值与分析法杂志》2020,44(13):1833-1853

Rockbust is a violent expulsion of rock due to the extreme release of strain energy stored in surrounding rock mass, leading to considerable damages to underground strucures and equipment, and threatening workers' safety. As the operational depth of engineering projects increases, a larger number of factors influence the mechanism of rockburst. Therefore, accurate classification of rockburst intensity cannot be achieved based on conventional criteria. It is urgent to develop new models with high accuracy and ease to implement in practice. This study proposed an ensemble machine learning method by aggregating seven individual classifiers including back propagation neural network, support vector machine, decision tree, k-nearest neighbours, logistic regression, multiple linear regression and Naïve Bayes. In addition, we proposed nine data imputation methods to replace the missing values in the compiled database including 188 rockburst instances. Five-fold cross validation and the beetle antennae search algorithm are used to tune hyperparameters and voting weights of the individual classifiers. The results show that the rockburst classification accuracy obtained by the classifier ensemble has increased by 15.4% compared with the best individual classifier on the test set. The predictor importance obtained by the classifier ensemble shows that the elastic energy index is the most sensitive input variable for rockburst intensity classification. This robust ensemble method can be extended to solve other classification problems in underground engineering projects.  相似文献   

吉林省道清矿北斜井南平峒煤层冲击地压危险性数值模拟     

于丽艳  潘一山  李忠华  李国臻  阎海鹏  王世娟 《中国地质灾害与防治学报》2011,22(1):94-98

通化矿业(集团)公司道清煤矿地质构造复杂,且已经进入深部开采阶段,煤体采动所形成的矿压对安全生产造成较大威胁。为预测该矿北斜井南平峒煤层冲击地压危险性的程度,对其煤层进行冲击地压危险性数值模拟,分析了煤层在自重应力场和构造应力场下水平应力、垂直应力、XY剪切应力大小及分布规律,得出应力集中区出现在F3号逆掩断层与煤层交汇处,即此处冲击地压危险性程度相对较大,开采时应注意防范,确保矿井安全开采。  相似文献   

圆形巷道围岩层裂或板裂化的等效连续介质模型及侧压系数的影响     

王学滨  伍小林  潘一山 《岩土力学》2012,33(8):2395-2402

为了避免均质和非均质模型不能较好地模拟围岩的层裂或板裂化现象,将岩石视为等效连续介质,即颗粒体材料。颗粒被视为弹性材料,而颗粒之间的界面破坏后被视为摩尔-库仑材料。颗粒和界面均被离散为正方形单元。采用FLAC研究了不同侧压系数时圆形巷道围岩中的剪切应变增量、最小、最大主应力等的分布规律。研究发现,颗粒体材料模型在压应力作用下诱发出的拉应力值接近于在模型边界上所施加的最大压应力,而最大压应力是所施加的最大压应力的数倍。这些结果意味着均质和非均质模型的计算结果是偏于不安全的。另外,最小主应力和剪切应变增量的等值线图均显示,这些量的高值区的距离大致相等,这与V形岩爆坑内的板裂化现象类似。围岩层裂现象的原因是环向的高压应力和径向的高拉应力的共同作用的结果。  相似文献