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1.
Stochastic seismic wave interaction with a slippery rock fault is studied, based on the principle of conservation of momentum
at the wave fronts along the fault. By using the displacement discontinuity method, the wave propagation equations are derived
for incident longitudinal-(P-) and shear-(S-) waves, respectively. This is an extension of the study by Li and Ma (2010) for
blast-induced wave propagation across a linear rock joint. Stochastic seismic waves are generated from a frequency spectrum
and used to analyze the seismic wave interaction with a rock fault having a Coulomb-slip behavior. Parametric studies are
carried out to investigate the effect of the intensity and impinging angle of the incident seismic waves on wave propagation
across a slippery rock fault. Results show that the transmission of the incident P-wave is almost not affected by the fault,
on the contrary, this is not the case for an incident S-wave, due to the occurrence of a relative slip which is related to
the impinging angle of the incident S-wave. A quantitative study is presented which is of help in understanding the propagation
and attenuation laws of seismic waves in discontinuous rock masses. 相似文献
2.
Analytical study of ground motion caused by seismic wave propagation across faulted rock masses 
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下载免费PDF全文 Studying seismic wave propagation across rock masses and the induced ground motion is an important topic, which receives considerable attention in design and construction of underground cavern/tunnel constructions and mining activities. The current study investigates wave propagation across a rock mass with one fault and the induced ground motion using a recursive approach. The rocks beside the fault are assumed as viscoelastic media with seismic quality factors, Qp and Qs. Two kinds of interactions between stress waves and a discontinuity and between stress waves and a free surface are analyzed, respectively. As the result of the wave superposition, the mathematical expressions for induced ground vibration are deduced. The proposed approach is then compared with the existing analysis for special cases. Finally, parametric studies are carried out, which includes the influences of fault stiffness, incident angle, and frequency of incident waves on the peak particle velocities of the ground motions. 相似文献
3.
In rock engineering, the damage criteria of the rock mass under dynamic loads are generally governed by the threshold values of wave amplitudes, such as the peak particle velocity and the peak particle acceleration. Therefore, the prediction of wave attenuation across fractured rock mass is important on assessing the stability and damage of rock mass under dynamic loads. This paper aims to investigate the applications of the discontinuous deformation analysis (DDA) for modeling wave propagation problems in rock mass. Parametric studies are carried out to obtain an insight into the influencing factors on the accuracy of wave propagations, in terms of the block size, the boundary condition and the incident wave frequency. The reflected and transmitted waves from the interface between two materials are also numerically simulated. To study the tensile failure induced by the reflected wave, the spalling phenomena are modeled under various loading frequencies. The numerical results show that the DDA is capable of modeling the wave propagation in jointed rock mass with a good accuracy. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
4.
Drilling and blasting is a major technology in mining since it is necessary for the initial breakage of rock masses in mining. Only a fraction of the explosive energy is efficiently consumed in the actual breakage and displacement of the rock mass, and the rest of the energy is spent in undesirable effects, such as ground vibrations. The prediction of induced ground vibrations across a fractured rock mass is of great concern to rock engineers in assessing the stability of rock slopes in open pit mines. The waveform superposition method was used in the Gol-E-Gohar iron mine to simulate the production blast seismograms based upon the single-hole shot vibration measurements carried out at a distance of 39 m from the blast. The simulated production blast seismograms were then used as input to predict particle velocity time histories of blast vibrations in the mine wall using the universal distinct element code (UDEC). Simulated time histories of particle velocity showed a good agreement with the measured production blast time histories. Displacements and peak particle velocities were determined at various points of the engineered slope. The maximum displacement at the crest of the nearest bench in the X and Y directions was 26 mm, which is acceptable in regard to open pit slope stability. 相似文献
5.
岩体工程计算分析中结构面刚度系数是至关重要的力学参数,计算分析的精度和可靠程度与这个参数密不可分,结构面刚度系数取值仍然是一个难点。岩体中应力波传播至结构面处将会发生反射和透射现象,利用应力波透射系数可反演结构面动态刚度系数。本文从细观力学角度运用颗粒离散元方法,开发分段线性接触模型及应力波吸收边界模型,开展宏观岩体中应力波传播的模拟,结合准静态压缩试验模拟,研究了较为平直的岩体结构面分别在不同正应力条件下的动、静态刚度系数的变化特征。模拟结果表明:(1)利用C++语言开发的分段线性接触模型很好地实现了结构面非线性变形特征的模拟;(2)基于颗粒离散元方法能够准确地反映岩体中应力波传播规律,应力波通过不同刚度结构面的透射系数与理论解一致;(3)在离散颗粒模型中加入黏滞吸收边界条件很好地实现了在有限尺寸模型中远场应力波传播模拟;(4)在岩体模型中结构面接触部位运用分段线性接触模型,通过模拟应力波传播与单轴压缩试验分别获得了一致性较好的结构面动、静态刚度系数,结构面动/静态刚度系数之比值约为1.0。本文对岩体中结构面刚度的测试和取值具有重要的指导意义。 相似文献
6.
Analysis of Wave Propagation Through a Filled Rock Joint 总被引：1，自引：1，他引：0
An analytical and experimental study on a longitudinal wave (P-wave) transmission normally across a filled rock joint is presented in this paper. The dynamic property of the filling material for the artificial rock joints is derived from a series of modified split Hopkinson pressure bar (SHPB) tests. The incident and transmitted waves in granitic pressure bars are calculated by wave separations of the strain gauge readings. The incident wave is approximated by a series of half-sinusoidal waves, and an analytical model on wave propagation across a filled rock joint is then deduced. The derived wave transmission coefficients across the filled joint agree very well with those from the test results. Both the analytical and test results show that the wave transmission coefficients are influenced by the mechanical properties and the input energy of the incident waves. Analytical parametric studies with respect to pre-compaction of the filling material, the frequency and amplitude of the incident wave have also been conducted. 相似文献
7.
8.
Sheng Zeng Shaoping Wang Bing Sun Qibing Liu 《Geotechnical and Geological Engineering》2018,36(3):1559-1573
The existence of joint fissures makes explosive actions between rock masses more complex. Therefore, it is of great significance to carry out experiments studying blasting stress waves propagating in jointed rock masses. Based on the Froude Similarity principle, the geological mechanical models of intact rock masses and jointed rocks have been proposed. A blasting vibration experiment was carried out and demonstrated that the propagation of the blasting stress waves and changing structures have an important relationship. A numerical simulation of the blasting stress wave propagation law in a layered jointed rock mass was carried out. This study found that with an increase in the joint angle, the peak velocity of blasting stress wave, transmission coefficient and reflection coefficient all gradually increased, while the attenuation coefficient gradually decreased. With an increase in joint spacing, the attenuation rate of the blasting stress waves increased. 相似文献
9.
Analysis of Blast Wave Interaction with a Rock Joint 总被引：8，自引：3，他引：5
The interaction between rock joints and blast waves is crucial in rock engineering when rock mass is suffered from artificial or accidental explosions, bursts or weapon attacks. Based on the conservation of momentum at the wave fronts and the displacement discontinuity method, quantitative analysis for the interaction between obliquely incident P- or S-blast wave and a linear elastic rock joint is carried out in the present study, so as to deduce a wave propagation equation. For some special cases, such as normal or tangential incidence, rigid or weak joint, the analytical solution of the stress wave interaction with a rock joint is obtained by simplifying the wave propagation equation. By verification, it is found that the transmission and reflection coefficients from the wave propagation equation agree very well with the existing results. Parametric studies are then conducted to evaluate the effects of the joint stiffness and incident waves on wave transmission and reflection. The wave propagation equation derived in the present study can be straightforwardly extended for different incident waveforms and nonlinear rock joints to calculate the transmitted and reflected waves without mathematical methods such as the Fourier and inverse Fourier transforms. 相似文献
10.
Effects of weak layers on particle velocity measurements 总被引：1，自引：0，他引：1
W. I. Fourney R. D. Dick X. J. Wang T. A. Weaver 《Rock Mechanics and Rock Engineering》1997,30(1):1-18
Summary Results are presented from a testing program to study the effect weak layers embedded in a strong rock strata have on particle velocity when subjected to explosive loading. A similar computational study had been conducted earlier with WONDY — a finite difference Langrangian code developed at Sandia National Laboratory. The experiments were conducted using models fabricated from Hydrocal containing a single dry sand layer or clay layer through which the stress wave traveled. Particle velocity was measured in front of and past the weak layer to determine attenuation, pulse shape changes, and displacement loss. The results from the model testing indicated that particle velocity amplitude decreased significantly when the stress wave passed through the weak layer. The velocity pulse width on the other hand was found to remain relatively constant when passing through the weak layer. The computational results from WONDY predicted similar behavior and hence were in good agreement with the tests. In the experiments, the velocity loss across a sand layer was found to be much larger than the loss across a clay layer. The stress wave velocity in the sand layer was found to be significantly smaller than in the Hydrocal while the experimentally determined wave velocity in the clay was nearly equal to the wave velocity in the Hydrocal. 相似文献
11.
12.
Nan Jiang Chuanbo Zhou Shiwei Lu Zhen Zhang 《Geotechnical and Geological Engineering》2018,36(3):1475-1489
Investigating the propagation and attenuation of blast vibration in rock slopes is the key point to assess the influence of underground mine blasting on overlaying open pit slopes stability and determining the potential risk. In this paper, Daye Iron Mine in China has been chosen as the case to study the effect of blast vibrations on overlaying open pit slopes due to underground mine blast. Firstly, the characteristics of blast loadings are analyzed by the dynamic finite element method. Then, a three dimensional (3D) numerical model of the open pit and the underground mine is made, which is verified by the field monitoring data to prove its reliability. The effect of blast vibration on overlaying open pit slope due to underground mine blasting are discussed based on the peak particle velocity (PPV) and the peak effective tensile stress (PETS) distribution characteristics which are calculated and analyzed by inputting the obtained blast vibration data into the numerical model. The results show that the effect of present mining blasting on the stability of pit slopes are limited because the simulated maximum PPV and PETS of monitoring point on slopes are all < 0.747 cm/s and 0.738 MPa. At last, according to numerical simulations of the underground mine blasting, the PPV predicting formulas for the slopes in Daye Open Pit Iron Mine is proposed based on the classic Sadaovsk formula. 相似文献
13.
Luigi Sambuelli 《Rock Mechanics and Rock Engineering》2009,42(3):547-556
I would like to suggest a theoretical justification for the mathematical structure of some laws for predicting the maximum
particle velocity vibration from blasting operations in the light of some basic notions of elastic and anelastic wave theory.
Within this point of view, in dimensionally correct expressions, the terms pertaining to the rock, to the blast and to the
seismic wave become evident and recognisable. A law is presented that can be used to forecast the maximum particle velocity
on the basis of some blast design and rock parameters. Four tests of the proposed law performed with real data sets seem to
confirm fairly well its reliability. 相似文献
14.
扭转导波在锚固锚杆中传播的数值模拟 总被引：1，自引：0，他引：1
采用有限元数值模拟的方法研究了扭转导波在锚固锚杆中的传播性质。建立了自由锚杆和锚固锚杆的有限元模型,在锚杆顶端激发20～60 kHz扭转导波信号,计算得到导波在自由锚杆和锚杆锚固段的传播速度值与理论值吻合很好,证明了扭转导波数值模拟方法的有效性。数值模拟结果表明：随着激发波频率的增大,扭转导波在自由锚杆和锚杆锚固段中的衰减值均呈线性递增趋势,导波在锚杆锚固段上界面的反射回波逐渐减弱;扭转导波在锚杆锚固段的衰减值较大,无法在锚杆顶端采集到锚杆底端反射回波信号,所以扭转导波不适用于锚杆长度的检测;随着锚固介质弹性模量的增大,同一频率扭转导波在锚杆锚固段上界面的反射波逐渐增强。通过检测扭转导波在锚杆锚固段上界面的反射回波,可以确定锚固介质弹性模量的大小。 相似文献
15.
A numerical study on 2-D compressive wave propagation in rock masses with a set of joints along the radial direction normal to the joints 总被引：1，自引：0，他引：1
An explosion in a borehole or an accidental explosion in a tunnel will generate a two-dimensional (2-D) compressive wave that travels through the surrounding rock mass. For the problem of 2-D compressive wave propagation in a rock mass with parallel joints in the radial direction normal to the joints, parametric studies on the transmission ratio and the maximum rebound ratio are performed in universal distinct element code. The variation of the transmission ratio with the ratio of joint spacing to wavelength is generalized into a characteristic curve, which can be used as a prediction model for estimating the transmission ratio. The relationship between the maximum rebound ratio and the influence factors is obtained in charts. The charts can be used as a prediction model for estimating the maximum rebound ratio. The proposed prediction models for estimating the transmission ratio and the maximum rebound ratio are applied to a field explosion test, Mandai test in Singapore. The minimum possible values of peak particle velocity (PPV) at the monitoring points are estimated by using the proposed prediction model for estimating the transmission ratio along the radial direction normal to the joints. On the other hand, the maximum possible values of PPV are estimated by using the proposed prediction model for estimating the maximum rebound ratio along the same radial direction. The comparison shows a good agreement between the field-recorded PPVs and the estimated range of PPVs given by the minimum possible PPVs and the maximum possible PPVs at the monitoring points in Mandai test. The good agreement between the estimated and field-recorded values validates the proposed prediction models for estimating peak particle velocity in a rock mass with a set of joints due to application of a compressive wave at the boundary of a tunnel or a borehole. 相似文献
16.
采矿爆破振动波在岩溶区的传播影响因素分析 总被引：1，自引：1，他引：0
为研究不同情况下爆破振动强度衰变规律和振动对岩溶塌陷的影响,为当地矿山合理开采及减少地面塌陷灾害的发生提供可靠依据,对湖南水口山铅锌矿区进行现场爆破振动测试,并利用古丹铅锌矿实测数据作对比分析;试验矿区共布设4条测线,接收8组爆破振动数据。采用萨道夫斯基修正公式对采集的数据进行计算,以爆破产生的振动波频率及振动速度作为测试指标,对实测数据进行提取、处理,确定爆破振动波的频率及其在介质中的传播速度及地震波引发的质点振动峰值振速。试验结果表明:采矿活动是岩溶地面塌陷的主要影响因素;爆破振动波的频率衰减强度与其在岩土体中的传播距离和断层有关,振动波的传播速度受到岩土体性质、岩层结构特征、岩层走向等因素的影响。 相似文献
17.
海原断裂带断层通道波观测与破碎带宽度 总被引：5，自引：0，他引：5
断层通道波是低速断层破碎带与高速围岩之间的边界相干多重反射形成的,其振幅和频率强烈依赖于断层的几何形态和物理性质,故能用于探测断裂带的内部结构.在宁夏海原西安州附近海原断裂带上,横跨1920年海原8.6级地震地表破裂带布设2条测线,接收测线之间人工爆破激发的断层通道波.每条测线由1台3分量数字地震仪组成,靠近破裂带台间距30～40 m,远离破裂带台间距增大至230～250 m.对测线1的台站接收到的一炮垂直道地震波数据进行了0.1～4.0 Hz频段的滤波,结果表明在S波到时之后存在多组强振幅、低频率、长波链的断层通道波.由断层通道波揭示的海原断裂带在西安州附近的断裂破碎带宽度约为250 m. 相似文献
18.
针对断层对周围岩石地层影响的问题,本文提出了一种有限元算法计算模拟该断层对周围地层产生的应力场和位移场。首先,根据最大主应力、中间主应力和最小主应力来研究正断层、逆断层以及走滑断层的应力状态;其次,基于弹性力学相关理论研究应力—应变关系,采用线性四面体单元有限元分析方法进行算法实现;最后,在考虑到断层两侧岩体的物理性质(弹性模量和泊松比)、断层几何形态以及边界条件等情况下,应用有限元法模拟正断层、逆断层以及走滑断层在层状岩体中产生的应力场和位移场。以红透山铜矿区F8断层为例,通过地质勘探获得的资料判别该断层性质及其周围地层属性,使用本文构建的有限元算法模拟了该断层对周围地层产生的应力场和位移场。 相似文献
19.
This paper presents a numerical model for predicting the dynamic response of rock mass subjected to large‐scale underground explosion. The model is calibrated against data obtained from large‐scale field tests. The Hugoniot equation of state for rock mass is adopted to calculate the pressure as a function of mass density. A piecewise linear Drucker–Prager strength criterion including the strain rate effect is employed to model the rock mass behaviour subjected to blast loading. A double scalar damage model accounting for both the compression and tension damage is introduced to simulate the damage zone around the charge chamber caused by blast loading. The model is incorporated into Autodyn3D through its user subroutines. The numerical model is then used to predict the dynamic response of rock mass, in terms of the peak particle velocity (PPV) and peak particle acceleration (PPA) attenuation laws, the damage zone, the particle velocity time histories and their frequency contents for large‐scale underground explosion tests. The computed results are found in good agreement with the field measured data; hence, the proposed model is proven to be adequate for simulating the dynamic response of rock mass subjected to large‐scale underground explosion. Extended numerical analyses indicate that, apart from the charge loading density, the stress wave intensity is also affected, but to a lesser extent, by the charge weight and the charge chamber geometry for large‐scale underground explosions. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
20.
Monia Aloui Yannick Bleuzen Elhoucine Essefi Chedly Abbes 《Arabian Journal of Geosciences》2018,11(21):686
Blasting constitutes a beneficial industrial technology, used in quarries and mining production processes, which ensures the achievement of the expected results in a short period of time with relatively low cost. Nevertheless, a significant part of the used blasting energy is wasted in the form of ground vibration and air blast. Hence, blasting-induced ground vibrations are one of the fundamental problems in the mining industry which may cause severe damage to structures and plants nearby. Therefore, a vibration control study plays an important part in the minimization of the environmental effects of blasting in mines. This study represents an investigation reporting ground motion (measured in terms of peak particle velocity (mm/s)) and air blast overpressure measurements around the open-pit phosphate mine near Metlaoui area (southwestern Tunisia). It aimed to calculate the site’s constants: K (ground transmission coefficient) and n (site attenuation curve slope). The obtained site parameters allowed determining the propagation equation of the blast-induced seismic waves in the study area. The scope of this study was to predict the peak particle velocity when the amount of explosive charge and/or the distance were altered with minimum spoil to the environment. Also, a frequency overview of the study area revealed the dominance of low frequencies (>?40 Hz). Such values can cause damage to the nearby structures when a specific peak particle velocity value is reached by blasting. Moreover, this study demonstrated that all overpressure magnitudes were less than 134 dB, which is the safe limit of air blast level. 相似文献