Estimation of in situ viscoelastic parameters of weak floor strata by plate-loading tests     

Gang Chen  Yoginder P. Chugh 《Geotechnical and Geological Engineering》1996,14(2):151-167

Summary This paper explores an approach to estimation of the viscoelastic parameters of weak floor strata using plate-loading tests. Mathematical equations are derived to describe deformation-time history for the standard Burgers model under three-dimensional stress-strain conditions, which are verified with a finite element model. A number of time-dependent in-mine plate-loading tests were conducted and the values of the viscoelastic parameters were estimated based on the derived equation. It is shown that large discrepancies between the parameter values estimated from the plate-loading tests and those acquired from the in-mine convergence data are the results of neglecting adjacent pillar interaction. Finite element modelling was conducted to investigate the effects of adjacent pillar interactions upon the pillar settlement. Based on the finite element analyses, a correction curve was developed to adjust the viscoelastic parameter values to take into account the interaction between adjacent pillars. With the correction, the parameter values estimated from the plate-loading tests compared favourably with those acquired from the in-mine convergence results.  相似文献   

Feasibility and cost of creating an iron-phosphate coating on pyrrhotite to prevent oxidation     

Z. J. Georgopoulou  K. Fytas  H. Soto  B. Evangelou 《Environmental Geology》1996,28(2):61-69

 Acid mine drainage (AMD) occurs when sulfide minerals are exposed to an oxidizing environment. Most of the methods for preventing AMD are either short-term or high cost solutions. Coating with iron phosphate is a new technology for the abatement of AMD. It involves treating the sulfide with a coating solution composed of H₂O₂, KH₂PO₄, and sodium acetate as a buffer agent. The H₂O₂ oxidizes the sulfide surface and produces Fe³⁺ so that iron phosphate precipitates as a coating on the sulfide surface. Experiments performed under laboratory conditions prove that an iron phosphate coating can be established on pyrrhotite surfaces with optimal concentrations of the coating solution in the range of: 0.2M/0.01M H₂O₂, 0.2M KH₂PO₄, and 0.2M sodium acetate NaAc, depending on the experimental scale. Iron phosphate coating may be a long-term solution to the problem of AMD. The method would be easy to implement; the reagent cost, however, is not low enough, although it is lower than the conventional treatment with lime. Received: 30 March 1995 · Accepted: 6 September 1995  相似文献   

Field assessment of acid mine drainage contamination in surface and ground water   总被引：4，自引：1，他引：4  

N. F. Gray 《Environmental Geology》1996,27(4):358-361

Both sulfate and conductivity are useful indicators of acid mine drainage (AMD) contamination. Unlike pH, they are both extremely sensitive to AMD even where large dilutions have occurred. The advantage of using sulfate to trace AMD is that unlike other ions it is not removed to any great extent by sorption or precipitation processes, being unaffected by fluctuations in pH. These two parameters are also closely associated as would be expected, as conductivity is especially sensitive to sulfate ions. Therefore, as sulfate analysis is difficult in the field, conductivity can be used to predict sulfate concentration in both AMD and contaminated surface waters using regression analysis. Most accurate predictions are achieved by using equations given for specific conductivity ranges or AMD sources. There is also potential to use conductivity to predict approximate concentrations of key metals when the pH of the water is within their respective solubility ranges.  相似文献   

淮南谢—矿煤的组成对甲烷吸附性的影响     

姚多喜 《中国煤田地质》1996,(Z1)

从淮南谢—矿五层煤（Ｃ＿（１３）、Ｂ＿（１１ｂ）、Ｂ＿（１０）、Ｂ＿（４ｂ）和Ａ＿３）中精选出镜煤、壳质暗煤、惰性暗煤及构造煤，采用重量法，分别测定它们的甲烷吸附量，从而研究不同成分组成的煤其甲烷吸附性能。  相似文献   

Heavy metal retention in secondary precipitates from a mine rock dump and underlying soil, Dalarna, Sweden   总被引：7，自引：2，他引：7  

Zhixun Lin  Roger B. Herbert Jr. 《Environmental Geology》1997,33(1):1-12

This study investigates the retention of heavy metals in secondary precipitates from a sulfidic mine rock dump and underlying podzolic soils by means of mineralogical and chemical extraction methods. The rock dump, which is at least 50 years old, consists of a 5–10-cm-thick leached zone and an underlying 110–115-cm-thick accumulation zone. Optical microscopy and electron microprobe analyses confirm that pyrrhotite weathering has proceeded much further in the leached horizon relative to the accumulation horizon. The weathering of sulfides in the leached zone has resulted in the migration of most heavy metals to the accumulation zone or underlying soils, where they are retained in more stable phases such as secondary ferric minerals, including goethite and jarosite. Some metals are temporarily retained in hydrated ferrous sulfates (e.g., melanterite, rozenite). Received: 28 October 1996 · Accepted: 24 February 1997  相似文献   

江西利山金矿床地质特征及控矿构造     

高文亮  聂剑华 《江西地质》1997,11(1):60-68

本文较系统地阐述了利山金矿床的各项地质特征，并重点就控矿构造问题进行了总结讨论，认为ＮＷＷ向断裂带严格控制了所有金矿体的产出。ＮＮＥ、ＮＮＷ向断裂与ＮＷＷ向断裂带的交汇部位控制了富矿段的产出。在此基础上初步探讨了矿床成因及找矿方向，这对该地区的找矿评价和开发均具有实际意义  相似文献   

正态化克立格法在路腊汞矿储量计算中的应用     

徐林生  唐昌骏 《吉林地质》1997,16(3):65-70

正态化克立格法是对传统储量计算方法的改革和创新。其计算过程的科学性和计算结果的正确性在路腊汞矿作了探采对比试算，取得了良好的结果。  相似文献   

RAMAC/GPR探地雷达在机场滑行道探测中的应用     

南生辉 《煤田地质与勘探》1997,(Z1)

采用RAMAC／GPR探地雷达对机场跑道传力杆进行探测试验，取得了令人满意的效果，为机场工程质量检测提供了一种有效手段。  相似文献   

判定地下水二维水动力弥散参数的直线图解法   总被引：1，自引：0，他引：1  

吴耀国  田春声 《煤田地质与勘探》1997,25(2):31-33

弥散参数的求得，是正确认识地下水污染运移及对其控制的前提。本文根据极值理论和非线性方程线性化手段，导出了浓度和时间变化的线性关系，得出了确定弥散参数的直线图解法。它可以弥补其它方法的不足。借用实际弥散试验资料对其进行了检验，表明所建数学模型与实际模型之间吻合良好，即所求得的参数结果可信。  相似文献   

口泉沟南水源地环境同位素研究和水资源评价   总被引：3，自引：0，他引：3  

吴剑锋  费光灿 《煤田地质与勘探》1997,25(3):35-39

分析了大同矿区口泉沟南区的水文地质条件，利用氢，氧，铀，硫，碳等环境同位素研究了口泉南与相邻的泉域和三层洞泉域的关系及地下水的补给来源；用有限元法进行了地下水资源评价和水位预报，证明在该区建立供水１０＾４ｍ＾３的水源地是可能的。  相似文献