An intelligent approach to prediction and control ground vibration in mines

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.     

Kalman filter estimation model in flood forecasting

Elementary precipitation and runoff estimation problems associated with hydrologic data collection networks are formulated in conjunction with the Kalman Filter Estimation Model. Examples involve the estimation of runoff using data from a single precipitation station and also from a number of precipitation stations. The formulations demonstrate the role of state-space, measurement, and estimation equations of the Kalman Filter Model in flood forecasting. To facilitate the formulation, the unit hydrograph concept and antecedent precipitation index is adopted in the estimation model. The methodology is then applied to estimate various flood events in the Carnation Creek of British Columbia.     

Application of multivariate analysis to suspended matter particle size distribution in a karst aquifer

Numerous quantitative and qualitative variables control suspended sediment dynamics in karst systems. The objective of this study was to identify the hydrodynamic variables controlling the transport properties of particles in a karst aquifer (western Paris basin). The particle size distribution of suspended sediment infiltrating via a swallow hole was compared to that in discharge from a spring, allowing identification of the particle transport properties of the karst system. Hill and Smith analysis, a type of multivariate analysis that allows joint examination of quantitative and qualitative variables, was used to identify the hydrodynamic parameters controlling the transport properties of the suspended matter. The results demonstrate that the particle size distribution discharging at the karst spring is controlled by spring discharge and the hydraulic gradient of the system. The hydraulic gradient is defined by the piezometric level and the stage of the Seine River, which is in turn controlled by the tide. This study illustrates the use of Hill and Smith analysis to identify those variables which control suspended sediment transport. It also illustrates the application of this analysis to identify boundary conditions and evaluate variables which control the behaviour of the hydrologic system. Copyright © 2007 John Wiley & Sons, Ltd.     

Petrologic and Geochemical Characteristics and Origin of Gusui Cherts,Guangdong Province,China

The characteristic structures of the Precambrian cherts from the Gusui section, Guangdong ,Chi-na, include bedded structure ,laminated structure ,massive structure and pseudobrecciated structure.The chert is characterized by consistently low abundance of TiO2,Al2O3 and most trace elements.Howevver ,it is enriched in Ba,As,Sb,Hg and Se.In Al-Fe-Mn ternary diagrams,it falls into the “hydrothermal field“ .Correspondence analysis and factor analysis show that many elements show up in the factor that represents the leaching of country rocks by hydrothermal solutions,and are the very characteristic element association fo the geochemically anomalous South China basement.Petrologic and geochemical evidence suggests a hydrothermal origin for the chert.The chert may have been formed in a Precambrian fift or an extension zone developed within the Yunkai marginal geosyncline, with a fault system linking it to an unknown heat source at depth.     

福建省环境地表γ辐射剂量率估算与人居环境安全性评价

福建省位于东南沿海,花岗岩大面积出露,导致土壤中的放射性核素普遍高,从而使环境地表γ辐射剂量率也较高.近年来,人居环境安全越来越受重视,较高的γ辐射剂量率是否存在风险成为人们关心的问题.本项目选择永安罗坊、武平忠地两处重点区开展1 ∶5万环境地表γ辐射剂量率测量,并在同点采集配套土壤样品.通过研究土壤放射性元素238U、232Th、40K比活度与γ辐射剂量率的关系特征建立多元回归方程,利用福建省1∶25万多目标区域地球化学调查所获得的31 303个表层土壤U、Th、K测试成果换算福建省2 kmx2 km网格环境地表γ辐射剂量率,编制人居环境适宜性评价图.得出福建省γ辐射安全区(无风险)约12.1万km2,占研究区总面积的99.64%.风险区(可能存在风险)433 km2.占0.36%.管制区(存在风险)仅4 km2.天然放射性人居环境优良.     

基于主成分-时间序列模型的地下水位预测

地下水位预测是区域水资源管理的重要依据。针对地下水位在时间序列上表现出高度的随机性和滞后性,建立了基于主成分分析与多变量时间序列CAR（Controlled Auto-Regressive）模型耦合的地下水位预报模型,将该模型应用于济南市陡沟灌区地下水位预测,结果显示,模型模拟值与实测值的决定系数R2和Nash-Suttcliffe系数E_ns均达到0.90以上;以2011年为基准年,当降水量减少10%~20%,蒸发量和生活用水量增加10%~20%,调入27.39万~137.0万m3地表水用于农业灌溉时,到2030年灌区地下水位将维持在30.99~31.29 m,较基准年上升0.12~0.42 m。在区域水资源紧缺的背景下,适当引入地表水灌溉,减少地下水的开采,灌区地下水位将逐步回升,对于灌区的可持续发展和区域水资源的合理利用具有重要意义。     

金蟾山金矿地球化学原生晕异常特征及找矿意义

文章通过对金蟾山金矿矿区地球化学原生晕的统计分析、微量元素异常等值线图分析、不同类型岩石统计及微量元素特征分析,认为矿区各微量元素均满足正态分布,最佳微量元素指示元素为Au,Cu,Hg,Bi;重要微量元素指示元素为Pb,Ag,As;Zn,W,Mo,Mn也可起到一定的指示作用;金矿脉的综合轴向分带序列为:Mo-Cu-Au...     

多元统计分析研究地层

应用有关多元统计分析方法来研究地层,进行化学地层划分的探讨、岩层分析等,为合理正确划分地层提供有效的定量依据,探讨有关方法的实用价值,丰富化学地层学的研究内容。结合实践,对一条实测地层剖面进行了较详细的分析研究,并与野外实际地质情况加以对比解释,从而揭示出更多的地质信息、规律,对地层有了更多的认识。