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土方量计算方法的比较与分析 总被引:1,自引:0,他引:1
在工程建设中,为了预算工程量就要计算工程所需要的土方量,计算土方量的方法不同,则计算的结果就会有区别,因此根据工程的实际情况选择不同的计算方法是非常有必要的.就方格网法、三角网法、断面法、等高线法四种计算土方量的方法进行比较,并分析各种计算方法的优缺点. 相似文献
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沉井法作为一种早期的特殊施工方法,不仅适于浅表土层,中深表土层亦可使用,所以沉深井是发展方向之一。 相似文献
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伊朗SAGHAND矿主立井设计有6个水平连接处,马头门施工是该工程的重点和难点。6个马头门结构复杂,地质条件各不相同,安全威胁大,施工中采取特殊的措施,保证了施工安全和工程质量,取得了良好的效果。 相似文献
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Seawater poses a great threat to the Xinli Mine, an undersea gold mine in China. A hydrochemical method was used to assess the risk of sea water inrush into the mine. A detailed hydrochemical survey and sampling were carried out and the concentrations of conservative ions in the mine water were analyzed. Principal component analysis indicated that the potential water inrush channels were located in the hanging wall of the ore-controlling fault. A composite principal component was calculated from the Na+, Cl?, Mg2+, SO4 2?, and K+ concentrations, which reflected the effects of potash feldspathization and cation exchange, to assess the risk of seawater inrush. 相似文献
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2007年,千秋煤矿按照河南省煤管局和义煤集团公司的安排部署,科学组织,狠抓落实,通过创新安全文化体系建设,创建标准化精品工程,实施科技兴矿战略,形成了独具特色的矿区文化体系."五优"矿井的创建,给千秋煤矿带来了巨大变化,使50年的老矿又焕发出了勃勃生机. 相似文献
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Laboratory and field treatment tests were performed to evaluate the effectiveness of lime treatment for mitigation of environmental
effects of acid mine drainage (AMD) at the Sarcheshmeh porphyry copper mine. AMD associated with the rock waste dumps is contaminated
with Al (>36,215 μg/L), Cd (>105 μg/L), Co (>522 μg/L), Cu (>53,250 μg/L), Mn (>42,365 μg/L), Ni (>629 μg/L), and Zn (>12,470 μg/L).
The concentrations of other metals (Fe, Mo, Pb, and Se) are low or below detection limits (As, Cr, and Sb). Due to the very
high Al and Mn content and the low concentration of Fe, a two-stage lime treatment method was chosen for the laboratory tests.
In the first stage, the AMD was treated at four pH set points: 7.5, 8.9, 9, and 10. In the second stage, after removing the
sludge at pH 9, treatment was continued at pH 10 and 11. The results indicated that a two-stage treatment method was not necessary
because elements such as Al, Cu, Co, and Zn were easily treated at pH 7.5, while complete removal of Cd, Mn, and Ni only required
a pH of 10. Increasing pH during the treatment process only caused a slight increase in Al. Field treatment tests support
the laboratory results. Lime treatment of highly contaminated AMD from dump 11, using simple low density sludge pilot scale
equipment, show that contaminant metals are treatable using this method. The mean treatment efficiency for contaminant metals
was 99.4% for Al, % for Cd, 99.6% for Co, 99.7% for Cu, 98.5% for Mn, 99.7% for Ni, 99% for U, and 99.5% for Zn. The optimum
pH for AMD treatment by lime was in the range of 9–10. The produced sludge in the treatment process was highly enriched in
the contaminant metals, especially Cu (>7.34%), Al (>4.76%), Mn (>2.94%), and Zn (>1.25%). A correlation coefficient matrix
indicates that the distribution pattern of the contaminant metals between soluble and precipitated phases is consistent with
the hydrochemical behavior of the metals during the lime treatment process. 相似文献
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