共查询到20条相似文献，搜索用时 421 毫秒
1.
Underground mining of coal seams in the Upper Silesian Coal Basin in Poland is accompanied by seismic activity of varying magnitude. The investigations which have been performed for several years distinguished high energy mine tremors connected directly with mining or coupled with geological structures, such as large faults. In mined seams, local fault zones occur. Faults in these zones are usually small, with throws comparable with coal seams thicknesses. Local fault zone may be responsible for the occurrence of high energy tremors as well as large faults, as presented in this article. An analysis of source mechanism of high energy tremors generated during longwall mining of the coal seam No. 510, with presence of a local fault zone, in one of the Polish hard coal mines in the Upper Silesian Coal Basin was performed. For this purpose, the seismic moment tensor inversion method was used. In most of foci, the process of shear predominated. Determined nodal plane parameters were correlated with parameters of faults forming the local fault zone. High energy tremors were generated mostly by dislocations on faults of the local fault zone. Weakening of roof rocks in the neighborhood of local fault zone takes an important role too, and was responsible for share of implosion in the focal mechanism. 相似文献
2.
矿山冲击的地震学研究与开发 总被引：15，自引：1，他引：15
国家地震局地球物理研究所与中国统煤总公司北京矿务局合作,将地震学的成熟方法引入对矿山冲击的研究。在监测系统改造、分析软件包编制、震源机理研究、矿山冲击分类和冲击预测专家系统研制等方面,都取得一定进展,并展示出极广阔的应用开发前景。本文则是这些工作的综合性总结。 相似文献
3.
Zhang Shaoquan Guan JieInsntute of Geophysics SSB Beijing China Beijing Mining Bureau Beijing China 《中国地震研究》1995,(1)
A sophisticated seismological method has been introduced to the study of mining tremors by the Institute of Geophysics,SSB in cooperation with the Beijing Mining Bureau of NCC.Achievements have been obtained in the following areas:modification of the seismic monitoring system,compilation of a software package for analysis of mining tremors,research on the mechanical model for mining tremors,classification of mining tremors and development of an expert system of tremor prediction. 相似文献
4.
Underground coal and copper ore exploitation in two Polish mining regions causes mining tremors and a series of other negative phenomena in the environment. Although these tremors are strictly connected with human activity, they differ considerably from other paraseismic vibrations. The moment of their occurrence is not to be foreseen likewise for earthquakes. The main problem discussed in the paper was formulated as the neural network evaluation of a relation between mining tremor energies, epicentral distances and acceleration response spectra. Back-propagation neural networks with Resilient back-propagation learning method were used. Each input vector included information about the mining tremor energy and the epicentral distance. Values of acceleration response spectrum were expected as the outputs of neural networks. Neurally evaluated spectra were compared with spectra computed on the basis of experimental data. After the network is trained and tested, it can be used for mapping of new data of mining tremor energies and epicentral distances into the spectra. Then, what is the substantial advantage of neural approach, the prediction of acceleration response spectra can be performed without recording of surface vibrations. In the light of the results, it is visible that the presented way of computation of acceleration response spectra can be peculiarly applied to prognosis of mining tremors influences on structures. 相似文献
5.
Induced seismicity in mines in Canada—An overview 总被引：1，自引：0，他引：1
Henry S. Hasegawa Robert J. Wetmiller Don J. Gendzwill 《Pure and Applied Geophysics》1989,129(3-4):423-453
Monitoring of mine-induced seismicity in Canada has improved with the expansion of regional seismograph networks into areas of active mining. However, the severity, and in some cases the frequency, of mine-induced tremors has increased as mining extends to greater depths and at accelerated rates of extraction. Because of the complex design and large areal extent of many mines (potash, coal and metalliferous), the most feasible and practical way to monitor these tremors at the present time is to deploy a network of seismometers in and on the surface above mines experiencing microearthquake activity. A few of these mines already have a network of seismometers deployed around them and plans are under way to deploy seismograph networks around other mines that have experienced some rather severe tremors in recent times. Six possible mechanisms for mine-induced tremors are described and the associatedP- andS-wave radiation patterns presented. A comparison of actual seismic radiation patterns with theoretical predictions is a quick way to diagnose the potential source mechanisms. In addition, recognizing the pattern of microearthquake activity preceding larger tremors can be used to mitigate the potential effects of severe tremors. 相似文献
6.
Analysis of spatial distribution of mining tremors occurring in Rudna copper mine (Poland) 总被引：1，自引：0，他引：1
Maria Kozłowska 《Acta Geophysica》2013,61(5):1156-1169
The distribution of mining tremors is strictly related to the exploitation progress of mining works and, consequently, to the local stress field. In case the distribution is known, it is possible to determine future area of intensive seismicity in exploited mining panel. In the paper, an analysis of working face-to-tremor distance for Rudna copper mine in Poland is presented. In order to develop a spatial model of tremors’ occurrence in the exploited mine, the seismicity of four mining sections in the five-month period was investigated and the tremors’ distribution was obtained. It was compared with the spatial distribution of tremors in coal mines found in the literature. The results show that the places where tremors mostly occur — the vicinity of the face, in front of it — coincide with the high-stress area predicted by literature models. The obtained results help to predict the future seismic zone connected with planned mining section, which can be used in seismic hazard analysis. 相似文献
7.
8.
从导出的地震定标律和地震破裂过程的断裂力学模式出发,得到了震源平均位移、速度和加速度谱的表达式,进而又推导出震源的峰值位移d_m,速度v_m和加速度a_m的表达式:d_m=k_dM_0~2/~3τ_0~(2/3),v=k_vM_0~(1/3)τ_0~(4/3),a_m=k_aτ_0~2式中M_0是地震矩,τ_0是环境剪应力值,k_d,k_v,k_a为适当的常数.我们选用了66个地震的观测资料,这些地震的矩震级范围包括了从1级左右的极微震,3-5级的小震,直到6-7级的大震;地震矩从10~9-10~(20)Nm,跨越了10个数量级,并用这些地震检验了上述公式. 令所有地震的平均应力为5MPa,定出常数k_d,k_v,k_a,进而由速度和加速度观测资料求得66个地震的环境剪应力τ_0值,这些数值相当稳定.多数极微震的τ_0值在2-4MPa之间;小震的τ_0值多数在4-8MPa左右;大震的τ_0值为10MPa左右。τ_0值对震源深度和断层类型有明显的依赖性.一般深度很浅的小震和极微震,τ_0值很低;正断层地震的τ_0值相对较低;逆断层地震的τ_0值较高;走滑断层地震的τ_0值则居中. 相似文献
9.
10.
Zbigniew Zembaty 《Bulletin of Earthquake Engineering》2011,9(5):1403-1416
Usually rockbursts from underground mining induce minor quakes of MM intensity up to V. Sometimes however the surface tremors
reach level of MM epicentral intensity I
0 = VI to VIII. Since a fast industrial development often takes place in the mining areas then some seismic design rules for
new buildings are needed. The main obstacle is then lack of respective design response spectrum and an unclear definition
of the level of design acceleration to apply. Particularly the latter one is difficult to overcome because the rockburst ground
motion records differ from natural earthquakes when it comes to their spectral properties as well as return periods. This
paper presents a method how to rationally define the design acceleration so that a seismic code, e,g, Eurocode 8, can be applied
in practical design procedures in the mining areas. 相似文献
11.
Reinforced concrete (RC) structures in low to moderate seismic regions and many older RC structures in high seismic regions include columns with steel reinforcement details not meeting the requirements of modern seismic design codes. These columns typically fail in shear or in a brittle manner and their behavior must be accurately captured when RC structures are modeled and analyzed. The total lateral displacement of a low ductility or shear critical RC column can be represented as the sum of three displacement components: (1) flexural displacement, (2) displacement due to slippage of the reinforcing bars at column ends, and (3) shear displacement. In this study, these three displacement components are separately modeled and then combined together following a proposed procedure based on the expected overall behavior of the column and its failure mechanism. A simplified slip model is proposed. The main objective of this research is to develop an easy-to-apply method to model and capture the cyclic behavior of RC columns considering the shear failure mechanism. The proposed model is validated using the available data from RC column and frame experiments. 相似文献
12.
2008年8.0级汶川大地震发生前约40 h起,中国地震局测震台网中的宽带地震仪、重力仪和倾斜仪都记录到了明显的低频扰动现象.然而,在此期间西太平洋上空产生了一次强台风Rammasun（威马逊）;与此类似,2001年8.1级昆仑山大地震发生前约60 h起,国家地震局测震台网中的宽带地震仪也记录到了明显的低频扰动现象,在此期间中国南海上空产生了一次强台风LingLing（玲玲）.本文针对这两大地震的“震前扰动”现象进行了研究,旨在探讨其“震前扰动”现象是否与台风引起的巨浪产生的地脉动效应有关.我们的研究结果表明：在中国内陆观测到的异常扰动与台风路径以及台风的强度密切相关.近海台风可在中国大陆内地引起明显的异常扰动;而远离大陆海岸位于深水海域上空的台风,很难在中国大陆内地引起明显的异常地脉动变化.台风LingLing的路径距离中国海岸最近处仅有约700 km,而台风Rammasun距离中国大陆海岸最近处却达1300 km.本文的对比分析研究表明：路径和强度类似于LingLing的台风在中国内陆可引起明显的异常扰动.因此,中国内陆和沿海许多地震台记录到的昆仑山大地震的“震前扰动”源于LingLing地脉动效应的可能性较大;但位于新疆的地震台记录到的扰动信号频率却明显偏低,这一现象值得注意.路径和强度类似于Rammasun的台风很难在中国内陆引起明显的异常扰动,因此汶川大地震的“震前扰动”完全源于台风Rammasun地脉动效应的可能性较小.汶川大地震的“震前扰动”产生的原因和机理值得我们去进行深入的探讨和研究. 相似文献
13.
A one-dimensional equivalent linear method (EQL) is widely used in estimating seismic ground response. For this method, the shear modulus and damping ratio of inelastic soil are supposed to be frequency independent. However, historical earthquake records and laboratory test results indicate that nonlinear soil behavior is frequency-dependent. Several frequency-dependent equivalent linear methods (FDEQL) related to the Fourier amplitude of shear strain time history have been developed to take into account the frequency-dependent soil behavior. Furthermore, the shear strain threshold plays an important role in soil behavior. For shear strains below the elastic shear strain threshold, soil behaves essentially as a linear elastic material. To consider the effect of elastic-shear-strain-threshold- and frequency-dependent soil behavior on wave propagation, the shear-strain-threshold- and frequency-dependent equivalent linear method (TFDEQL) is proposed. A series of analyses is implemented for EQL, FDEQL, and TFDEQL methods. Results show that elastic-shear-strain-threshold- and frequency-dependent soil behavior plays a great influence on the computed site response, especially for the high-frequency band. Also, the effect of elastic-strain-threshold- and frequency-dependent soil behavior on the site response is analyzed from relatively weak to strong input motion, and results show that the effect is more pronounced as input motion goes from weak to strong. 相似文献
14.
The paper deals with the mechanical origin and rules ofen echelon folds and their secondary fractures by means of elastic stability theory and nonlinear fracture criterion. Obtains the quantitative
relations amongen echelon angles ofen echelon folds, ratios of boundary stresses anden echelon pitches of shear zone under an action of general boundary forces (tension shear, pure shear or compression shear). As an
applied example, the paper researches the displacement field, stress field, distortion energy distribution, state of secondary
fractures and energy released by fracturing ofen echelon fold structure developed at the east foot of Taihang Mountain. The results of research show that maximum principal (compressive)
stresses, maximum shear stresses, high value area of distortion energy are in the nuclear parts ofen echelon folds. In these parts compressive fractures were easily developed in approximately parallel with fold axis. So it is verified
that the secondary fracture ofen echelon folds is a mechanism controlling a strong earthquake. 相似文献
15.
Human perception to tremors during earthquakes in high-rise buildings is usually associated with psychological discomfort such as fear and anxiety. This paper presents a methodology for estimating the level of perception to tremors for occupants living in high-rise buildings subjected to ground motion excitations. Unlike other approaches based on empirical or historical data, the proposed methodology performs a regression analysis using the analytical results of two generic models of 15 and 30 stories. The recorded ground motions in Singapore are collected and modified for structural response analyses. Simple predictive models are then developed to estimate the perception level to tremors based on a proposed ground motion intensity parameter—the average response spectrum intensity in the period range between 0.1 and 2.0 s. These models can be used to predict the percentage of occupants in high-rise buildings who may perceive the tremors at a given ground motion intensity. Furthermore, the models are validated with two recent tremor events reportedly felt in Singapore. It is found that the estimated results match reasonably well with the reports in the local newspapers and from the authorities. The proposed methodology is applicable to urban regions where people living in high-rise buildings might feel tremors during earthquakes. 相似文献
16.
峰后的刚度劣化现象（渐进损伤）在多种煤、岩石、混凝土、土和砂子的循环加载实验中已被观察到。本文考虑了剪切带及带外弹性体的不同的刚度劣化现象,推导了剪切带（断层）-弹性围岩系统在直剪条件下的应力-变形曲线。剪切带的刚度劣化不改变剪切带的总变形,但使剪切带的弹性变形增加、塑性变形降低。考虑弹性体的刚度劣化现象之后,系统的峰后应力-变形曲线呈现非线性特征,这不同于过去忽略刚度劣化现象的结果。在应变软化过程中,剪切带之外弹性体的刚度劣化,使系统的峰后响应由负斜率（Ⅰ类行为）变为正斜率（Ⅱ类变形行为）。较高的弹性体尺寸、较高的脆性、较小的内部长度、较低的围岩初始弹性模量、较高的抗剪强度、较低的残余剪切应力及较高的残余剪切弹性模量,使系统的峰后响应变得陡峭,甚至发生Ⅱ类行为,使系统的失稳（岩爆、冲击地压、采矿诱发地震或矿震）易于发生。 相似文献
17.
2019年5月26日（北京时间）秘鲁北部发生M7.8地震,震源深度为100km。本文利用国际地震学研究联合会数据管理中心（IRIS/DMC）提供的远场波形数据,通过波形反演方法快速反演得到此次地震的矩张量解和破裂过程。W震相快速矩张量解反演结果表明此次地震是一次中深源正断层型地震事件,可能是由于正在向下俯冲的纳斯卡板块产生规模巨大的伸展变形所致。远震体波反演有限断层模型结果显示此次地震的发震断层为高倾角的NNW向断层面,破裂从初始破裂点开始,由震中主要向NNW方向延伸破裂,最大滑移量约3m;地震破裂时间约为70s,在40~60s时释放了整个地震80%的地震矩能量,主要破裂区域在震后40s后才开始形成,在40s之前,破裂的集中程度和地震矩释放的规模均较弱,断层在破裂开始后逐渐加速破裂,约50s时地震矩释放速率达到峰值,60s后破裂迅速愈合。 相似文献
18.
H. U?ur Koyliioglu Ahmet ?. Çakmak Søren R.K. Nielsen 《Soil Dynamics and Earthquake Engineering》1997,16(2):95-112
A nonlinear hysteretic model for the response and local damage analyses of reinforced concrete shear frames subject to earthquake excitation is proposed, and, the model is applied to analyse midbroken reinforced concrete (RC) structures due to earthquake loads. Each storey of the shear frame is represented by a Clough and Johnston hysteretic oscillator with degrading elastic fraction of the restoring force. The local damage is numerically quantified in the domain [0,1] using the maximum softening damage indicators which are defined in closed form based on the variation of the eigenfrequency of the local oscillators due to the local stiffness and strength deterioration. The proposed method of response and damage analyses is illustrated using a sample 5 storey shear frame with a weak third storey in stiffness and/or strength subject to sinusoidal and simulated earthquake excitations for which the horizontal component of the ground motion is modeled as a stationary Gaussian stochastic process with Kanai-Tajimi spectrum, multiplied by an envelope function. 相似文献
19.
煤矿冲击矿压现象日益严峻,作为矿山动力灾害的主要监测手段,微震监测系统已在许多矿井广泛使用,为保证矿震定位和能量计算的准确,提高预测预报煤矿冲击矿压的可行性,应建立一套台网布设优化及评价系统.应用微震定位和D值优化设计理论,结合煤矿实际条件研究了影响矿震定位精度的主要因素和不利条件,并提出了采用综合指数法确定煤矿高微震活动区域和区域内矿震发生的概率,制定了台站候选点和监测区域确定的一般原则.通过理论分析震中和震源标准差反映台网定位能力的不足,建立基于数值仿真实验方法的震中与震源误差期望值模型,最终形成台网布设优化及评价系统.实验和现场应用结果表明,该系统能够快速确定台网最优布设方案,准确评价台网定位能力,满足煤矿微震监测的需要. 相似文献
20.
We report here the observation result of joint observation of long period tremor signals with broadband seismome-ter,tiltmeter and gravimeter at the HUST(Huazhong University of Science and Technology)station.The observed data were compared and analyzed.Since 2005,the several tens of abnormal tremor signals which are weak,com-plex and duration of 2 to 3 days have been synchronously recorded by the different instruments.The tremor signals have the periodic domain in the range of 3 to 5 minutes,20 to 30 minutes and even more than 1 hour.The observa-tion shows such tremors are a physical existence.The analysis indicates that a part of the tremors caused by the typhoon from the western Pacific Ocean.These tremors have a close relationship with wind velocity of typhoon and distance between the typhoon center and the station.Except these,the cause of others is still unclear. 相似文献