Reliability level III method in design of square pillar resting on weak floor stratum

Summary Current methods of design of pillars resting on weak floor strata involve only a deterministic, conventional safety factor calculation, based on material parameters treated as the mean values taken from observations. In a case where high parameters variability occurs, these methods may lead to fatal design errors resulting in excessive pillar settlement and roof falls. Therefore, to include the influence of parameters quality, the new approach based on reliability level III method was developed. Consideration was given to the identification of the system parameters importance, and to density function for the safety factor treated as a random variable. Design procedure involving floor probability of failure was illustrated by numerical examples.     

北京市矿山地质环境评价

通过对1443处（1661个）矿山的实地调查,采用地质环境指数法进行评估,利用ArcGIS软件,使用＂natural breaks＂（自然断点法）分级法,圈定出矿山地质环境影响严重区、较严重区和轻微区,提出了治理对策建议。     

淄博煤矿矿坑排水对地表水体的污染及对地下水水质影响的研究

以山东淄博煤田富硫煤（w（St＞2％）煤矿作为典型研究区,阐述了由于直接排放酸性、高SO4离子、高硬度和较高矿化度（TDS）的矿坑水导致的地表水体及地下水的污染。研究区内地表水体的水质主要受控于矿坑排水的质量,区内主要河流、水库已被污染。引用这种受污染的地表水进行灌溉,会引起浅层地下水的严重污染,并影响到饮用此类地下水的人们的身体健康。为揭示污水灌溉过程中水-岩相互作用及地下水污染的机理,进行了现场土柱模拟实验,分别模拟了污水灌溉和降水入渗过程。实验结果表明,污水灌溉过程中SO4-不会被吸附,也不会产生沉淀,因此,污水灌溉是污灌区地下水受污染的主要原因。降水入渗实验表明,污灌区土壤中的SO4-,Ca2+和Mg2+,也可以通过降水淋滤进入地下水,这是污灌区地下水受污染的另一条途径。就对水环境的影响而言,酸性煤矿矿坑排水的环境效应是负面的,应予以高度重视。     

深部找矿与蒋氏TEM双定源回线装置方案

双定源回线装置的水平场Hx,其强度大、均匀,有利于探测深部陡倾斜金属矿藏,并可用作远距离井中测量的场源。此方案可用于危机矿山的找矿工作。     

Attributes and uncertainty of dissolved zinc data from a mined catchment

This study evaluated the attributes and uncertainty of non‐point source pollution data derived from synoptic surveys in a catchment affected by inactive metal mines in order to help to identify and select appropriate methods for data analysis/reporting and information use. Dissolved zinc data from the Upper Animas River Basin, Colorado, USA, were the focus of the study. Zinc was evaluated because concentrations were highest relative to national water quality criteria for brown trout, and zinc had the greatest frequency of criteria exceedances compared with other metals. Data attributes evaluated included measurement and model error, sample size, non‐normality, seasonality and uncertainty. The average measurement errors for discharges, concentrations and loadings were 0·15, 0·1 and 0·18, respectively. The 90 and 95% coefficients of confidence intervals for mean concentrations based on a sample size of four were 0·48 and 0·65, respectively, and ranged between 0·15 and 0·23 for sample sizes greater than 40. Aggregation of data from multiple stations decreased the confidence intervals significantly, but additional aggregation of all data increased them as a result of increasing spatial variability. Unit area loading data were approximately log‐normal. Concentration data were right‐skewed but not log‐normal. Differences in median concentrations were appreciable between snowmelt and both storm flow and baseflow, but not between storm flow and baseflow. Differences in unit area loadings between all flow events were large. It was determined that the average concentration and unit area loading values should be estimated for each flow event because of significant seasonality. Time weighted values generally should be computed if annual information is required. The confidence in average concentrations and unit area loadings is dependent on the computation method used. Both concentrations and loadings can be significantly underestimated on an annual basis when using data from synoptic surveys if the first flush of contaminants during the initial snowmelt runoff period is not sampled. The ambient standard for dissolved zinc for all events was estimated as 1600 μg l⁻¹ using the 85th percentile of observed concentration data, with a 90% confidence interval width of 200 μg l⁻¹. Copyright © 1999 John Wiley & Sons, Ltd.     

高分辨率航磁方法及在大冶铁矿区的应用

本文针对危机矿山深部及周边找矿的难度大、勘探周期短的特点,提出了一套以找矿为目的,集直升机大比例尺航空物探测量、数据处理、解释为一体的高分辨率航磁方法技术.这些方法包括硬架式直升机航磁测量方法、曲面位场处理方法、精细反演解释方法等.应用该方法在湖北黄石大冶铁矿中布钻,已有两孔见富磁铁矿及伴生的铜、金矿,见矿最大厚度为14.6m.因此,高分辨率航磁方法在危机矿山进一步挖潜工作中可以实现快速找矿目的.     

我国露天煤矿水害特征与防治水技术

露天开采是我国煤矿开采的两大方式之一。与地下开采煤矿类似,露天煤矿在开采过程中同样面临防治水问题,由于我国露天煤矿水害类型相对单一,国内学者鲜有对露天煤矿的水害特征和防治水技术进行深入研究。以我国露天煤矿分布范围为出发点,从充水水源、充水通道、充水强度3方面分析露天煤矿水害特征,得出大气降水、地表水和浅层地下水是主要充水水源;人为开挖形成的直通式通道、强渗透含水层或透水层、垂向导水钻孔、滑坡形成的地表裂缝等是主要充水通道;季节性变化明显、疏排水周期长、排水量大是露天煤矿疏排水主要水害特征的结论。归纳目前我国露天煤矿常用的7种防治水技术,提出露天煤矿由远及近、由上而下、由面至点的立体防治水技术体系。从地下水资源保护和生态环保角度出发,为实现露天煤矿绿色开采和可持续发展,提出以切断补给通道、减小矿坑疏排水量为目的的帷幕截流技术是今后露天煤矿防治水的主要技术方法。     

Synthetic information prediction system for crisis mine based on GIS

Reserves of some kinds of the crisis mines will be lack now or from now on, because of lacking seriously reserves of mineral resources and the crisis of exploring bases in support. So that it is urgent to predict, appraise, development and utilize the replaceable resources of the crisis mines. The mineral resources prediction software system of synthetic information is intelligent GIS which is used to quantitative prediction of large-scale synthetic information mineral target. It takes the geological body and the mineral resource body as a unit. And it analyzes the ore deposit genesis and metallotect, knows the spatial distribution laws of the ore deposit and ore body, and establish the prospecting model based on the concept of establishing the three-dimensional space of a mine. This paper will primarily discuss some important problems as follows: the secondary development of various kinds of data(including geology, geophysical prospecting, geochemical prospecting and remote sensing, etc); process synthetically and establish the synthetic information interpretative map base; correspond prospecting model with synthetic information of ore deposit; divided into statistical units of metallogenic information synthetic anomalies based on the synthetic information anomalies of ore control, then research the metallogenic information variable of unit synthetically and make quantitative prediction according to choose the quantitative prediction math model which is suitable to the demands of large-scale precision; at last, finish the target area optimization of ore deposit (body).