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1.
A database of ground vibration due to blasting at 27 limestone quarries, located in various parts of India, has been created. The database contains peak particle velocity (PPV), frequency, other vibration related and blast design parameters. Regression analysis of the data is carried out to derive site constants of the USBM predictor equation for individual quarries. It is found that these site constants are correlated with each other. By combining all the data, a generalised predictor equation is developed to assess and control ground vibration. In addition, mean zone of attenuation has been delineated using the predictor equations of the individual quarries. The dominant frequency of ground vibration with respect to distance and the possibility of modifying it by changing delay intervals in production blasts are also examined.  相似文献   

2.
Flyrock is an adverse effect produced by blasting in open-pit mines and tunneling projects. So, it seems that the precise estimations and risk level assessment of flyrock are essential in minimizing environmental effects induced by blasting. The first aim of this research is to model the risk level associated with flyrock through rock engineering systems (RES) methodology. In this regard, 62 blasting were investigated in Ulu Tiram quarry, Malaysia, and the most effective parameters of flyrock were measured. Using the most influential parameters on flyrock, the overall risk of flyrock was obtained as 32.95 which is considered as low to medium degree of vulnerability. Moreover, the second aim of this research is to estimate flyrock based on RES and multiple linear regression (MLR). To evaluate performance prediction of the models, some statistical criteria such as coefficient of determination (R2) were computed. Comparing the values predicted by the models demonstrated that the RES has more suitable performance than MLR for predicting the flyrock and it could be introduced as a powerful technique in this field.  相似文献   

3.
The quantitative analysis of fracturation heterogeneity from Geographic Information System (GIS) has become very important for the modelling of underground quarries stability, the reservoir properties deduced from fracturing and their consequences on the groundwater run-off. This paper aims to give a method of quantitative analysis of fracturing in three underground limestone quarries of Gironde. More than 1000 fractures were measured, mapped and numbered. The heterogeneity analysis and the fracturing connectivity are based on the spatial distribution of geometrical parameters of each fracture, such as: openness, length, direction, orientation, spatial distribution of different fracture classes and connexity. To cite this article: A. Cerepi, C. R. Geoscience 334 (2002) 163–170.  相似文献   

4.
The environmental effects of blasting must be controlled in order to comply with regulatory limits. Because of safety concerns and risk of damage to infrastructures, equipment, and property, and also having a good fragmentation, flyrock control is crucial in blasting operations. If measures to decrease flyrock are taken, then the flyrock distance would be limited, and, in return, the risk of damage can be reduced or eliminated. This paper deals with modeling the level of risk associated with flyrock and, also, flyrock distance prediction based on the rock engineering systems (RES) methodology. In the proposed models, 13 effective parameters on flyrock due to blasting are considered as inputs, and the flyrock distance and associated level of risks as outputs. In selecting input data, the simplicity of measuring input data was taken into account as well. The data for 47 blasts, carried out at the Sungun copper mine, western Iran, were used to predict the level of risk and flyrock distance corresponding to each blast. The obtained results showed that, for the 47 blasts carried out at the Sungun copper mine, the level of estimated risks are mostly in accordance with the measured flyrock distances. Furthermore, a comparison was made between the results of the flyrock distance predictive RES-based model, the multivariate regression analysis model (MVRM), and, also, the dimensional analysis model. For the RES-based model, R 2 and root mean square error (RMSE) are equal to 0.86 and 10.01, respectively, whereas for the MVRM and dimensional analysis, R 2 and RMSE are equal to (0.84 and 12.20) and (0.76 and 13.75), respectively. These achievements confirm the better performance of the RES-based model over the other proposed models.  相似文献   

5.
Flyrock is one of the most hazardous events in blasting operation of surface mines. There are several empirical methods to predict flyrock. Low performance of such models is due to complexity of flyrock analysis. Existence of various effective parameters and their unknown relationships are the main reasons for inaccuracy of the empirical models. Presently, application of new approaches such as artificial intelligence is highly recommended. In this paper, an attempt has been made to predict and control flyrock in blasting operation of Sangan iron mine, Iran incorporating rock properties and blast design parameters using artificial neural network (ANN) method. A three-layer feedforward back-propagation neural network having 13 hidden neurons with nine input parameters and one output parameter were trained using 192 experimental blast datasets. It was also observed that in ascending order, blastability index, charge per delay, hole diameter, stemming length, powder factor are the most effective parameters on the flyrock. Reducing charge per delay caused significant reduction in the flyrock from 165 to 25 m in the Sangan iron mine.  相似文献   

6.
The first discoveries of pterosaur fossils were made at the end of the 18th century and during the first decades of the 19th century in Bavaria, southern Germany. They originate from limestone quarries in the vicinity of the village of Solnhofen and adjacent hamlets as well as from limestone pits close to the town of Eichst?tt.  相似文献   

7.
At least 1.5 × 106 m3 of oolitic limestone from the Corinthia was quarried during antiquity, mainly for construction. Previously, it has only been possible to speculate about the sources of oolite in ancient constructions because of its uniformity on the macroscopic scale. However, thin section petrography demonstrates a considerable degree of petrographic variation within the oolite of one group of quarries at Examilia, 4.5 km ENE of Ancient Corinth. Variation in the characteristics of the ooids and the amount and types of noncarbonate grains in the oolite from different quarries permit the identification of five petrographically distinct zones in the Examilia quarries. This offers great potential as a high resolution provenancing tool, and the data have numerous other archaeological applications. Following these results, the work has been extended to become a comprehensive study of all Corinthian oolite quarries. © 1996 John Wiley & Sons, Inc.  相似文献   

8.
Paleocene limestone and dolomitized limestone of Álava, Spain, were used as building materials from the Neolithic age until the Neoclassical, predominantly in the production of headstones, sculpture, and stonework during the Roman era (1st to 4th centuries) and Romanic and Gothic periods (10th to 15th centuries). The quarrying methods employed are related to topographic relief. Five types of ancient quarry have been identified: escarpment, dip‐slope (ascending and descending), edge, and trench. The oldest quarries (1st to 4th centuries) are the trench‐cut stone pits of “Raso de Cezama.” Later, from the Romanic period (10th to 15th centuries), descending dip‐slope, escarpment, and edge‐based quarries were worked, such as those at Achuri, Ajarte, and Santa Elena. Finally, an ascending dip‐slope quarry was developed at Marquínez during the Neoclassical period (18th century). © 2009 Wiley Periodicals, Inc.  相似文献   

9.
Flyrock is a rock thrown to greater distance than desired and is a dangerous and unwanted phenomenon in surface mines, particularly, when blasting is proceeding close to human occupation and dwellings. The prediction of flyrock distance is critical in defining the statutory danger zone of blasting and has evaded blasters for quite some time. Control of flyrock with its distance prediction involves identification of key variables and understanding their influence. Theoretical models though provide a good understanding of the phenomenon, the confidence that can be assigned to such models is still very less. This study presents novel method to identify, merge and consolidate independent variables into a simplified equation for flyrock distance prediction without compromising on the actual field applications. Field investigations were carried out in several mines and relevant data were generated relating to flyrock. The key parameters, namely, explosive, blast design and rock mass nature were characterized and analysed. An empirical model involving the key contributors for flyrock generation and distance prediction were assimilated and a new equation was developed based on actual data collected by employing surface response analysis. The developed model was found to be statistically significant and validated. Sensitivity analysis was conducted to ascertain the role of independent factors on flyrock distance.  相似文献   

10.
Blasting operation should be performed satisfying some criteria, such as fragmentation, flyrock, and cost. To reach the most appropriate alternative among previous performed blast designs, all the criteria should be simultaneously considered in the analysis. To do so, rather new emerging approaches such as Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), a branch of multi-criteria decision-making techniques could be applied. Using TOPSIS method, the present study tries to investigate the blasting operation in the Tajareh limestone mine and select the most appropriate blasting pattern. According to the obtained results, alternative ten with hole diameter of 64 mm and staggered pattern designed by Ash formula, was selected to be the best decision. Application of this alternative comparatively satisfies both fragmentation and flyrock.  相似文献   

11.
为了消除露天采石场残山存在的崩塌、滑坡等地质灾害隐患,减轻废弃土石对大气的污染,恢复原有的生态环境,本文以东平县石灰石露天采场综合治理为例,探讨了硬岩场地矿山地质环境恢复治理的综合方法,包括针对边坡进行放坡、对采坑进行推高垫低的工程施工方法,生态恢复物种的选取和培育方法等,为其它类似采石场地质环境的综合治理提供借鉴.  相似文献   

12.
This paper is an application of artificial neural networks (ANNs) in the prediction of the geometry of surface blast patterns in limestone quarries. The built model uses 11 input parameters which affect the design of the pattern. These parameters are: formation dip, blasthole diameter, blasthole inclination, bench height, initiation system, specific gravity of the rock, compressive and tensile strength, Young's modulus, specific energy of the explosive and the average resulting fragmentation size. Detailed data from a previous investigation were used to train and verify the network and predict burden and spacing of a blast. The built model was used to conduct parametric studies to show the effect of blasthole diameter and bench height on pattern geometry.  相似文献   

13.
Blasting is sometimes inevitable in civil engineering work, to fragment the massive rock to enable excavation and leveling. In Minyak Beku, Batu Pahat also, blasting is implemented to fragment the rock mass, to reduce the in situ rock level to the required platform for a building construction. However, during blasting work, some rocks get an excessive amount of explosive energy and this energy may generate flyrock. An accident occurred on 15 July 2015 due to this phenomenon, in which one of the workers was killed and two other workers were seriously injured after being hit by the flyrock. The purpose of this study is to investigate the causes of the flyrock accidents through evaluation of rock mass geological structures. The discontinuities present on the rock face were analyzed, to study how they affected the projection and direction of the flyrock. Rock faces with lower mean joint spacing and larger apertures caused excessive flyrock. Based on the steoreonet analysis, it was found that slope failures also produced a significant effect on the direction, if the rock face failure lay in the critical zone area. Empirical models are often used to predict flyrock projection. In this study five empirical models are used to compare the incidents. It was found that none of the existing formulas could accurately predict flyrock distance. Analysis shows that the gap between predicted and actual flyrock can be reduced by including blast deign and geological conditions in forecasts. Analysis revealed only 69% of accuracy could be achieved if blast design is the only parameter to be considered in flyrock projection and the rest is influenced by the geological condition. Other causes of flyrock are discussed. Comparison of flyrock prediction with face bursting, cratering and rifling is carried out with recent prediction models.  相似文献   

14.
A hybrid dimensional analysis fuzzy inference system approach was introduced to predict blast-induced flyrock in surface mining, by integrating a dimensional analysis procedure and Mamdani’s fuzzy inference system. In the dimensional analysis, the blast-induced flyrock was considered as a function of the most effective parameters. Hence, a number of dimensionless products resulted and were used as input and output parameters of Mamdani’s fuzzy inference system. The capability of the hybrid approach was determined by comparing its results with the real measurement of flyrock in the case of a copper mine, based on a number of 320 in situ blasting datasets. Predictions by the system were close to the real measurements. Sensitivity analysis of the hybrid dimensional analysis fuzzy inference system showed that the most effective dimensionless products on flyrock distance were spacing, the multiplication of rock mass rating and hole length, and the subtraction of burden and hole length multiplication and stemming length.  相似文献   

15.
The Isle of Portland is one of the jewels in the crown of the ‘Jurassic Coast’ of Dorset, southern England. Thomas Hardy aptly described this limestone peninsula as the ‘Gibraltar of Wessex’, and used its stone quarries as the backdrop for one of his novels (The Well‐Beloved). Quarries then, as now, work the world‐famous Portland Stone—a Jurassic oolitic limestone—from which St Paul's Cathedral and many other well‐known buildings are constructed. Rocks exposed in the numerous disused quarries scattered across the isle, together with exposures in spectacular sea‐cliffs, paint a vivid picture of life and environments, ～150 million years ago. In addition to Jurassic patch‐reefs, coastal sabhkas, fossil forests and dinosaur footprints found in the bedrock, more recent geological phenomena include two Quaternary raised beaches, solution caves filled with vertebrates, and massive coastal landslips. The aim of this article is to provide a field guide for those wishing to explore the geology of this little‐known region for themselves.  相似文献   

16.
An ideally performed blasting operation enormously influences the mining overall cost. This aim can be achieved by proper prediction and attenuation of flyrock and backbreak. Poor performance of the empirical models has urged the application of new approaches. In this paper, an attempt has been made to develop a new neuro-genetic model for predicting flyrock and backbreak in Sungun copper mine, Iran. Recognition of the optimum model with this method as compared with the classic neural networks is faster and convenient. Genetic algorithm was utilized to optimize neural network parameters. Parameters such as number of neurons in hidden layer, learning rate, and momentum were considered in the model construction. The performance of the model was examined by statistical method in which absolutely higher efficiency of neuro-genetic modeling was proved. Sensitivity analysis showed that the most influential parameters on flyrock are stemming and powder factor, whereas for backbreak, stemming and charge per delay are the most effective parameters.  相似文献   

17.
Limestone quarrying and quarry reclamation in Britain   总被引：1，自引：1，他引：0  
Limestones have been worked for many thousands of years — initially for building stone and agricultural lime and more recently for a wide range of construction and industrial uses. In most industrialized countries limestone quarries represent the most visually obvious and, in both process and landform terms, the most dramatic anthropogenic impact on karst terrain. However, quarrying has, to date, received surprisingly little attention from karst scientists. Research in the English Peak District suggested that the postexcavation evolution of quarried limestone rock faces was in part a result of the methods used in their excavation, and this led to the development of a technique designed to reduce the visual and environmental impacts of modern quarries by Landform replication. This involves the use of controlled restoration blasting techniques on quarried rock slopes to construct a landform sequence similar to that in the surrounding natural landscape. The constructed landforms are then partially revegetated using appropriate wildflower, grass, and/or tree species.  相似文献   

18.
The type, use, and size of the structural stones employed in three ancient cities of the Aegean Thrace are considered Abdera, Maroneia, and Mesimbria. The impact of the geological environment on the choice of these materials also is examined. From the results obtained it is implied that despite the great variety of rocks exposed in the area, the rocks used in construction in these cities are mostly types of sandstone and limestone, rocks with moderate technical properties and easily obtained from the area. The quarries were within a radius of less than 10 km and the size distribution of the building stones in all towns is discussed.  相似文献   

19.
Zeev Lewy 《Geoarchaeology》2006,21(2):187-196
The Zedekiah Cave is situated within an area of ancient limestone quarries. The quarried tunnel system extends more than 200 m from the small entrance. Important reasons must have prompted the transition to technically complicated subsurface activity. Quarrying proceeded mainly along a single layer of porous bioclastic limestone. The fresh, wet rock is friable, easily cut and carved. When exposed and dried, the blocks become casehardened from the periphery inward. Such rock was needed for renovation of the Second Temple under the religious restrictions that no iron (metal) tool should be used at the holy site, and these blocks could be finally shaped with nonmetallic tools. These unique geological and religious factors resulted in the subsurface quarrying of the building stones. Hence, the Zedekiah Cave was dug some 565 years after King Zedekiah allegedly fled through the cave out of Jerusalem to Jericho where the Babylonian soldiers captured him. © 2006 Wiley Periodicals, Inc.  相似文献   

20.
The Comblanchien limestone is a well-known building stone that deserves a quantitative characterization in order to be able to certify its origin. We compare petrographical and geochemical characteristics of limestones commercialized under the name of Comblanchien to those of one of their competitors (VATC, a Portuguese coated grain-bearing limestone). From macroscopic and microscopic observations, the distinction is somehow difficult but the coated grain-bearing Comblanchien samples have δ13C values (from +1.75 to +2.25‰) different from those of the VATC sample (negative δ13C value). As an example of application of these results, three samples from a building site near Paris are also studied in order to verify their provenance. We conclude that they do not come from quarries from the Comblanchien area, but likely from Portugal. The study shows that a detailed analysis of building limestones may provide a robust tool for discriminating between currently mined stones of different provenances, and thus open the possibility to attach to a given limestone a fingerprint, an identity card, and if required a commercial label.  相似文献   

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