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1.
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
2.
Vivek K. Himanshu M. P. Roy A. K. Mishra Ranjit Kumar Paswan Deepak Panda P. K. Singh 《Arabian Journal of Geosciences》2018,11(16):460
Excavation of coal, overburden, and mineral deposits by blasting is dominant over the globe to date, although there are certain undesirable effects of blasting which need to be controlled. Blast-induced vibration is one of the major concerns for blast designers as it may lead to structural damage. The empirical method for prediction of blast-induced vibration has been adopted by many researchers in the form of predictor equations. Predictor equations are site specific and indirectly related to physicomechanical and geological properties of rock mass as blast-induced ground vibration is a function of various controllable and uncontrollable parameters. Rock parameters for blasting face and propagation media for blast vibration waves are uncontrollable parameters, whereas blast design parameters like hole diameter, hole depth, column length of explosive charge, total number of blast holes, burden, spacing, explosive charge per delay, total explosive charge in a blasting round, and initiation system are controllable parameters. Optimization of blast design parameters is based on site condition and availability of equipment. Most of the smaller mines have predesigned blasting parameters except explosive charge per delay, total explosive charge, and distance of blast face from surface structures. However, larger opencast mines have variations in blast design parameters for different benches based on strata condition: Multivariate predictor equation is necessary in such case. This paper deals with a case study to establish multivariate predictor equation for Moher and Moher Amlohri Extension opencast mine of India. The multivariate statistical regression approach to establish linear and logarithmic scale relation between variables to predict peak particle velocity (PPV) has been used for this purpose. Blast design has been proposed based on established multivariate regression equation to optimize blast design parameters keeping PPV within legislative limits. 相似文献
3.
A detailed examination of the frequency content of ground vibration is presented in terms of the so-called instantaneous frequency and time-frequency analysis. These techniques, and others, are applied to the surface vibration from a mass blast that triggered a large seismic event and to an earthquake vibration measured in the walls of a massive dam. As an associated issue it is shown that the relationship between peak levels of acceleration and velocity also reveals information on the frequency content of ground vibration. It is demonstrated quite clearly that the popular zero-crossing method cannot be used to obtain the frequency associated with the peak vibration level. In fact it is a false notion that one particular frequency can be associated with the peak level except for the ideal (and impractical) case of a single sinusoid. Realistically, there is a distribution of frequencies associated with the peak level, and a technique of sliding filters is suggested in order to examine the dependence of the peak level upon this frequency content. In light of the sliding filter approach, a new frequency dependent criterion for allowable levels of vibration is presented. This criterion is a completely continuous and well-defined function of frequency and so is more realistic than the current criteria which are only piecewise continuous and based upon an ill-defined frequency. The new criterion is applied to vibration data obtained from quarries and underground operations and is also applied to a model of resonant vibrations in urban dwellings. 相似文献
4.
Pure white marble has been considered a valuable ornamental and architectural material since ancient times. Many scientific techniques have been used to create an extensive data base of “finger-prints” characterizing white marbles from the major classical quarries. However, determining the provenance of white marbles is a difficult task due to their similarity in physical and chemical parameters. Three techniques (petrography, cathodoluminescence and stable C and O isotopes) have been used to characterize white marbles from the ancient quarries of the Iberian Peninsula. Maximum grain size, texture and isotopic composition can be used to identify the different quarries. Each area is generally represented by several cathodomicrofacies, but quantitative CL analysis is also helpful in distinguishing those quarries for which the data provided by other techniques are not sufficiently diagnostic. The database and the discriminating criteria presented in this study have been tentatively applied to some ancient sculptures from the National Museum of Roman Art in Merida (Spain). 相似文献
5.
Drilling and Blasting are still considered to be the most economical method for rock excavation either on surface or underground. The explosive energy, which breaks the rockmass, is not fully utilized for this purpose. Only 20–30% of explosive energy is utilized for fragmenting the rockmass and the rest wasted away in the form of ground vibration, air blast, noise, fly rock, back breaks, etc. Among them, ground vibration is considered to have the most damaging effect. A number of predictor equations have been proposed by various researchers to predict ground vibration prior to blasting. Still, it is difficult to recommend any one predictor for a particular ground condition because ground vibration is influenced by a number of parameters. These parameters are either controllable or non-controllable like blast geometry, explosive types, rock strength properties, joints patterns, etc. In the present paper, an attempt has been made to predict the ground vibration using an Artificial Neural Network incorporating large number of parameters, which affect the ground vibration. Results are also compared with the values obtained from regression analysis and observed field data sets. Finally, it is found that the neural network approach is more accurate and able to predict the value of blast vibration without increasing error with increasing number of inputs and non-linearity among these. 相似文献
6.
Mohamed Sobaih 《Geotechnical and Geological Engineering》2011,29(3):249-258
Population increase and development plans in Egypt require the establishment of many new cities near Cairo. One of these cities
is the 15th of May City located about 30 km south of Cairo. The site of this city is very near from two quarries belonging
to two cement companies. The inhabitants used to complain from the blastings in these quarries. At a certain stage some buildings
have suffered different levels of damage. Upon the request of official authorities a study program has been performed to identify
the causes and the safety of five chosen buildings. The program included experimental testing to measure the vibration of
the chosen buildings during blasting operations. Three-dimensional structural analysis has been also performed. Results have
showed that the damage was due to Dahshour Earthquake of Oct. 12th, 1992 and not due to quarry blastings. Many other useful
conclusions have been obtained. 相似文献
7.
为评价地铁环境振动对某中心城区拟建住宅办公楼的影响,本文使用高灵敏度测试仪TROMINO对该建筑场地进行了24 h环境振动测试,得到了场地3个方向加速度和速度的实测数据。采用1/3倍频程分析法对实测数据进行处理,分析了不同时段场地振动变化规律,并将分析结果与国际标准ISO 2631关于此类建筑场地的振动限值进行对比。结果表明:有地铁运行时的环境振动峰值远大于无地铁运行时;无地铁运行时,地面振动加速度幅值介于10-5~10-1 gal之间,且无明显振动主频;有地铁运行时,振动幅值介于10-4~100 gal之间,并在晚高峰时段达到最大值0.8 gal;地铁运行引起的地面振动主频介于40~50 Hz之间。低频段内（2~8 Hz）场地振动加速度最大值约为0.030 gal,中高频段内（8~250 Hz）场地振动速度最大值为26.715 μm ·s-1,均满足标准要求。 相似文献
8.
Prediction of blast-induced air overpressure (AOP) is very complicated and intricate due to the number of influencing parameters affecting air wave propagation. In this paper, an attempt has been made to predict the blast-induced AOP by support vector machine (SVM) using maximum charge per delay and distance from blast-face to monitoring station of AOP. To investigate the suitability of this approach, SVM predictions are compared with a generalized predictor equation. Seventy-five air blasts were monitored at different locations around three mines. AOP data sets of two limestone mines are taken for the training and testing of the SVM network as well as to determine site constants for generalized equation. The remaining mine data sets are used for the validation and comparison of AOP. 相似文献
9.
Yagoub M. M. Alsereidi Aishah A. Mohamed Elfadil A. Periyasamy Punitha Alameri Reem Aldarmaki Salama Alhashmi Yaqein 《Natural Hazards》2020,100(1):111-132
Prediction and control of blast-induced ground vibration is a matter of concern in mining industry since long. Several approaches ranging from scaled distance regression, different numerical methods to wave superimposition theories have been tried by many researchers for better prediction and control of blast-induced ground vibration. Signature hole analysis is one of the popular simulation methods to predict the ground vibration generated due to production blast. It superimposes the recorded signature hole waveform using a computer program to predict the production blast-induced vibration. The technique inputs the designated time of detonation of each hole and superimposes the waves generated by each hole to predict the nearest value of peak particle velocity and frequency of blast-induced ground vibration. Although a very useful approach, it requires a computer program to simulate the linear superimposition of waveforms. The simulation is not possible for every blast as it takes time and also is difficult for field engineers to simulate every time, whereas it is always easy for blasting engineers to adapt and use an empirical equation/approach for prediction and control of blast-induced ground vibration than simulation. In this paper, an attempt has been made to develop an innovative and simplified analytical approach of signature hole analysis. The simplified sinusoidal wave equation is obtained from recorded signature hole ground vibration waveform properties and is superimposed mathematically according to the multi-hole blast design to predict the production blast-induced ground vibrations. The validation of the developed approach was done in three different sites, and up to 15% more accuracy in prediction of the blast, vibrations are achieved in comparison with signature hole analysis prediction.
相似文献10.
城市轨道交通造成环境的振动“污染”不容忽视。通过现场测试和理论分析,得到南京地面轨道交通运行引起的大地竖向振动加速度幅值、频率随距离轨道中心线不同位置的衰减规律,即随着与轨道水平距离的增加,大地竖向振动加速度幅值总的趋势表现为逐渐减弱,但在距离轨道中心线20～30 m之间振动幅值有所反弹;振动加速度的频率集中在0～ 100 Hz,最大值出现在30～80 Hz左右,随着与轨道水平距离的增加,各频率的振动信号分量总的趋势是减弱,且频率愈高衰减愈快。基于“北京交通大学”预测公式,建立包含受振点距离、地基土性质、列车速度3个参数的南京地面轨道交通运行引起大地振动的预测模型,与实测数据相比,吻合较好。 相似文献
11.
浅埋大跨隧道施工爆破监测与减震技术 总被引：4，自引：1，他引：3
以沪-蓉线庙垭分岔隧道工程为背景,研究了其浅埋大跨段掘进爆破的地表震动效应及大断面开挖减震控制技术,并结合爆破监测数据的回归分析,确立了地震波垂向衰减规律的数学模型。综合分析地表及洞内地震波的震动特性发现,地表质点振动主振频率主要集中在低频段;由于表土的滤波作用,主振频率随距离的增加而减小的趋势并不明显;洞内混凝土衬砌减弱了爆破对围岩的冲击,高频地震波衰减极快;开挖区上部的地表振速通常大于未开挖区的振速,浅埋大跨隧道爆破安全控制应以已开挖区顶部的地表振速为准。 相似文献
12.
A new site-specific vibration prediction equation was developed based on site measurement performed in a sandstone quarry. Also, several vibration prediction equations were compiled from the blasting literature and used to predict ground vibration for the studied quarry. By this way, site-specific equation created by regression analysis and the equations obtained from the blasting literature were compared in terms of prediction accuracy. Some of the equations obtained from the literature made better predictions than the site-specific equation created for the studied quarry. The prediction equations were grouped, and the effects of the rock formation and mine type on the prediction accuracy were investigated. Suitable error measures for evaluation of ground vibration prediction were examined in detail. A new general prediction equation was created using site factors (K, β) of the examined studies. The general equation was created using 17 prediction equations reported by blast researchers. Prediction capability of the general equation was found to be strong. Diversity of the blast data is one of the strongest features of the general equation. 相似文献
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基于高速列车运行引起的轨道-桥梁-桥墩-季节性冻土区场地的地面振动和沉降问题, 选取哈大高速铁路铁岭至四平段某桥墩及周围基础场地为测试段, 对实测数据从时域和频域两方面进行分析, 研究了桥墩及周围不同场地的振动特性, 结果表明:桥墩和基础场地的振动特性存在很大的差异, 基础场地对振动有放大效应, 且不同基础场地对振动的放大效果也明显不同。结合实测概况建立了桥墩-基础场地有限元数值模型, 分析桥墩及基础场地在不同季节的振动传播特性, 以及基础场地土体内部的应力分布情况, 并利用累积塑性应变模型对重复列车荷载作用下季节性冻土区基础场地的沉降变形进行分析, 发现场地振动加速度峰值随与桥墩距离R的增大而衰减, 且在冻结季的振动衰减速度明显小于非冻结季的; 基础场地地表的累积沉降在距桥墩R=0.5 m处最大, 且随着列车荷载作用次数的增加而增加, 最后逐步趋于稳定。 相似文献
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针对地基隔振控制,提出了一类新型的空沟?波阻板联合隔振屏障,并对其隔振性能进行了数值分析。首先,利用复伸展坐标变换,在频域内建立了完全匹配层（perfect matched layer, PML）吸收边界的控制方程;其次,利用Galerkin近似技术,给出了以位移为基本未知量的二阶非分裂格式PML的频域有限元计算列式;最后,通过数值算例分析了空沟?波阻板联合隔振屏障的物性参数（地基与波阻板的模量比）、几何参数（空沟深度、波阻板深度）以及载荷参数（振动波频率）等对其隔振性能的影响规律。结果表明,空沟?波阻板联合隔振屏障结合了空沟和波阻板各自的优势,可以有效地控制不同频率振源引起的地基振动。 相似文献
18.
Assessment of predominant frequencies using ambient vibration in the Kachchh region of western India: implications for earthquake hazards 总被引：1，自引：1，他引：0
The Kachchh region is the second most seismically active region in India after the Himalaya. One of the disastrous Indian earthquakes of the millennium was the Bhuj earthquake of January 26, 2001, which caused about 14,000 casualties and huge property damage. The main reason for such devastation is due to lack of earthquake awareness and poor construction practices. Hence, an increase in the knowledge and awareness, based on improved seismic hazard assessment, is required to mitigate damage due to an earthquake. Natural predominant ground frequencies have been investigated in the Kachchh region of western India using ambient vibrations. The horizontal-to-vertical spectral ratio technique has been applied to estimate the predominant frequency at 126 sites. The ambient vibration measurements were conducted for about 1 h at each site in the continuous mode recording at 100 samples/s. We have validated the estimated predominant frequency with earthquake data recorded at six broadband stations in the region. It has been observed that geological time period has a significant effect on predominant frequency of the ground. The estimated predominant frequencies vary from 0.24 to 2.25 Hz for the Quaternary, 0.41–2.34 Hz for the Tertiary, 0.32–4.91 Hz for the Cretaceous, and 0.39–8.0 Hz for the Jurassic/Mesozoic. In the Deccan trap, it varies from 1.30 to 3.80 Hz. We found distinct variation of predominant frequencies of sites associated with hard rock and soft soil. The predominant frequencies were related to the thickness of the sediments, which are deduced by other geophysical and geological methods in the region. Our results suggest that frequencies of the region reveals the site characteristics that can be considered for studying the seismic risks to evolve a plan for disaster risk mitigation for the region. 相似文献
19.
基于Abaqus软件64CPU并行计算集群平台,建立了车辆-轨道-高架桥-基础-地基耦合的三维有限元分析模型。得到了不同工况下列车运行时引起的地表振动特征,对地表振动振级随着与桥墩距离增大而衰减的规律进行了参数化分析,结果表明,随着列车车速的增大,地表振动振级明显增大;与空载时相比,列车乘客满载时仅靠近桥墩处的地表振级略微增大,对远处几乎无影响;列车车厢数量对地表振动振级的影响不明显;列车双线运行时引起的地表振动振级比单线运行时有明显的增大。扣件刚度的增大会略微减小地表振动振级。随着桩长的增加,地表振动振级有较大幅度的减小;增加桥墩的跨度能减小地表振动振级,但增加到一定值时再增加也不会有明显的减振效果;桥墩高度对地表振动振级无明显影响。随着场地土层剪切波速的增加,地表振动振级呈逐渐减小的趋势。 相似文献
20.
This paper highlights the seismic microzonation carried out for a nuclear power plant site. Nuclear power plants are considered to be one of the most important and critical structures designed to withstand all natural disasters. Seismic microzonation is a process of demarcating a region into individual areas having different levels of various seismic hazards. This will help in identifying regions having high seismic hazard which is vital for engineering design and land-use planning. The main objective of this paper is to carry out the seismic microzonation of a nuclear power plant site situated in the east coast of South India, based on the spatial distribution of the hazard index value. The hazard index represents the consolidated effect of all major earthquake hazards and hazard influencing parameters. The present work will provide new directions for assessing the seismic hazards of new power plant sites in the country. Major seismic hazards considered for the evaluation of the hazard index are (1) intensity of ground shaking at bedrock, (2) site amplification, (3) liquefaction potential and (4) the predominant frequency of the earthquake motion at the surface. The intensity of ground shaking in terms of peak horizontal acceleration (PHA) was estimated for the study area using both deterministic and probabilistic approaches with logic tree methodology. The site characterization of the study area has been carried out using the multichannel analysis of surface waves test and available borehole data. One-dimensional ground response analysis was carried out at major locations within the study area for evaluating PHA and spectral accelerations at the ground surface. Based on the standard penetration test data, deterministic as well as probabilistic liquefaction hazard analysis has been carried out for the entire study area. Finally, all the major earthquake hazards estimated above, and other significant parameters representing local geology were integrated using the analytic hierarchy process and hazard index map for the study area was prepared. Maps showing the spatial variation of seismic hazards (intensity of ground shaking, liquefaction potential and predominant frequency) and hazard index are presented in this work. 相似文献