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基于无量纲的三元露天采场性能评价体系研究 被引量:2
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作者 崔铁军 马云东 +1 位作者 白润才 王来贵 《煤炭学报》 EI CAS CSCD 北大核心 2014年第A01期83-87,共5页
目前的采场性能评价方法得到的结果是有量纲的,无法比较形状和尺度不同的采场性能,而且对超欠采体的形状特征考虑不充分。针对该问题构建了一组无量纲的评价指标体系,并基于该指标对一些基本形状采场进行特征分析。指标由圆度(C)、延度... 目前的采场性能评价方法得到的结果是有量纲的,无法比较形状和尺度不同的采场性能,而且对超欠采体的形状特征考虑不充分。针对该问题构建了一组无量纲的评价指标体系,并基于该指标对一些基本形状采场进行特征分析。指标由圆度(C)、延度(E)和半球度(H)组成,圆度(C)表示超欠采面的规则程度;延度(E)表示超欠采面的分散性及覆盖性;半球度(H)表示超欠采体的等效深度。研究确定了这3个无量纲指标值的范围及其划分语义和数值范围。该评价指标体系实现了评价方法、评价指标和评价标准的统一,进而实现了无量纲的采场性能比较。通过对4个模拟采场进行评价,得到了3个指标的评价值和语义,并确定了采场的潜在失效方式。 展开更多
关键词 露天 无量纲 采场性能 评价体系 构建
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基于非形状及尺度的露天采场性能评价 被引量:4
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作者 崔铁军 马云东 白润才 《系统工程理论与实践》 EI CSSCI CSCD 北大核心 2014年第12期3274-3280,共7页
采场性能是通过最大开采量和最小贫化率确定的.目前的评价方法得到的结果是基于尺度的,无法比较不同尺度采场性能,而且不能考虑超欠采体的形状特征.针对上述问题本文构建了一组与尺度无关的评价指标.研究已有的评价指标,对一些基本形状... 采场性能是通过最大开采量和最小贫化率确定的.目前的评价方法得到的结果是基于尺度的,无法比较不同尺度采场性能,而且不能考虑超欠采体的形状特征.针对上述问题本文构建了一组与尺度无关的评价指标.研究已有的评价指标,对一些基本形状进行特征分析.提出用圆度(C)表示超欠采面的规则程度;用延度(E)表示超欠采面的分散性及覆盖性;用半球度(H)表示超欠采体的等效深度;用相对体积(Rv)总体评价采场性能.确定了这四个无量纲指标值的范围和各指标的划分语义及其数值范围.构建的评价指标体系做到了评价方法、评价指标和评价标准的统一,这样就实现了不同尺度采场性能的比较.通过对4个构造的采场进行评价,得到了四个指标的评价值和语义,最后确定了各自的潜在失效方式.结果表明该方法简单易行,结果符合实际情况. 展开更多
关键词 露天 非尺度相关 形状-大小 采场性能 评价体系
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Variation of vertical and horizontal drilling rates depending on some rock properties in the marble quarries 被引量:7
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作者 Servet Demirdag Nazmi Sengun +3 位作者 Ibrahim Ugur Tamer Efe Deniz Akbay Rasit Altindag 《International Journal of Mining Science and Technology》 SCIE EI 2014年第2期269-273,共5页
The main objective of this study is to determine the rates of vertically and horizontally oriented drilling processes in marble quarries and to observe the factors affecting the drilling rates in terms of physical and... The main objective of this study is to determine the rates of vertically and horizontally oriented drilling processes in marble quarries and to observe the factors affecting the drilling rates in terms of physical and mechanical properties of the rocks. In situ drilling tests were performed in different marble quarries with different marble types and drilling times and penetration rates for a series of successive depthincrements were trying to be determined under vertically and horizontally oriented conditions. In order to understand the relation between the parameters that are investigated within the scope of this research, uniaxial compressive strength, Brazilian tensile strength, impact strength, Bohme abrasion strength, P-wave velocity, porosity, unit volume weight, Schmidt hardness index and brittleness index values were correlated with the drilling rates. It was noticed that the porosity and unit volume weight could be taken as the key parameters among them for obtaining meaningful correlation with drilling performance. It was also observed that the physical and mechanical rock properties are more relevant in vertical drilling than horizontal drilling. 展开更多
关键词 Mechanical properties Drilling Drilling rate Marble quarry
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Assessment of green roof performance for sustainable buildings under winter weather conditions 被引量:2
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作者 J.Srebric 《Journal of Central South University》 SCIE EI CAS 2012年第3期639-644,共6页
A green roof is a specialized roof system that supports vegetation growth on rooftops.This technology is rapidly gaining popularity as a sustainable design option for buildings.In order to contribute to an understandi... A green roof is a specialized roof system that supports vegetation growth on rooftops.This technology is rapidly gaining popularity as a sustainable design option for buildings.In order to contribute to an understanding of green roof in regions with cold winters and snow,an on-site experimental investigation was present with a focus on the assessment of green roof performance during the winter.This field experiment took place on a six small buildings during the winter of 2010-2011.The work monitored three buildings with green roofs,two buildings with reference roofs and one building with a bare soil coverage for the roof.These six buildings were identically constructed and instrumented with sensor networks to provide heat flux data through the roofs.The 15 min averaged data were statistically analyzed for a week under the two separate periods,first without a snow cover and second with a snow cover.The results show that the roof type is a significant factor in affecting the thermal performance of these buildings.Most importantly,green roofs reduce heat flow through the roof and thus reduce the heating energy demand during the winter.However,the energy savings for buildings with the green roofs are reduced under snow conditions because the snow diminishes thermal resistance of the roof and increases the heat transfer process through the roofs. 展开更多
关键词 green roof energy savings building envelop sustainable buildings
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