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991.
G. L. Sivakumar Babu Satyanarayana Murthy Dasaka 《Geotechnical and Geological Engineering》2008,26(1):37-46
The effect of directional behaviour of correlation structure of cone tip resistance on the bearing capacity of shallow strip
footing resting on cohesionless soil deposit in 2-D random field is analysed using probabilistic approach. The results obtained
from the analysis show that the assumption of perfect (or infinite) correlation of cone tip resistance data leads to lower
values of probability of failure. In contrast, the isotropic assumption of correlation behaviour based on vertical scale of
fluctuation leads to higher values of probability of failure. The results also show that the transformation model would play
a major role in the evaluation of variability of design property. In conclusion, the need for a proper evaluation methodology
for calculation of correlation lengths of soil properties and their influence in foundation design is highlighted. 相似文献
992.
The interface between environmentalism and neoliberalism in industrialised nations is dynamic and evolving with each of these significant socio-political movements exerting influence on the other. In the context of Australian environmental policy, ideas of heritage, sense of place and belonging are increasingly invoked to support the current policy emphasis on the role of regional communities for realising goals for land and water conservation and environmental restoration. To explore the broader meaning and consequences of these developments, we focus on the manner in which ideas of heritage are employed and evoked within the Murray–Darling Outreach Project, a collaboration between the Murray–Darling Basin Commission, a key natural resource management agency, and the National Museum of Australia. The Murray–Darling Outreach Project has the aim of increasing community involvement in local environmental issues by promoting ideas of vernacular heritage. 相似文献
993.
The use of temporal mixture analysis (TMA) for creating a long-term baseline, or environmental “normal” is described. TMA is a promising analysis method derived from the hyperspectral image processing technique of spectral mixture analysis (SMA). TMA is algebraically identical to SMA, except that it is applied to temporal spectra rather than to electromagnetic spectra. TMA has particular potential to extract climate signals from long image sequences. 相似文献
994.
995.
针对中国247个农业气象土壤水分观测站点1981 2010年逐旬土壤重量含水量、逐年田间持水量、凋萎湿度和土壤容重,考虑地区气候特点和土壤质地,依据土壤水分极值和水文常数关系理论,制定了土壤水分观测历史数据集质量控制方法,对土壤水分数据奇异值进行分析与校正。结果表明:土壤水分观测历史资料中,奇异值问题可以归结为人工录入误差、多地段水文常数混用误差和年际变化异常;土壤重量含水量数据异常问题归结为小于风干土含水量和大于理论饱和含水量的极端情况。通过对历史数据集质量控制后,可以对土壤水分观测数据进行有效推广应用,为针对土壤水分的研究提供重要科学基础。 相似文献
996.
Douglas E. Booth 《社会与自然资源》2017,30(11):1404-1420
Postmaterialist theory suggests that under conditions of continuously expanding economic and personal security, younger generations will be less oriented to acquiring material goods and more committed than their older peers to attaining postmaterial social goals such as increased free self-expression and a healthy natural environment. Using the latest World Values Survey sample for the United States, ordinary least squares (OLS) and logit regressions are employed to test whether youth is a predictor of postmaterialism as theory suggests, and whether postmaterialism positively predicts environmental concern and individual actions in support of the environment. Age is found to be a negative and statistically significant factor in explaining variation in the postmaterialism index, and this index is in turn found to be a statistically significant positive factor in explaining individual environmental concern and activism. A combination of increased economic security and entrance of younger generations into adulthood could well matter for our environmental future. 相似文献
997.
基于海洋功能区划的海域开发利用承载力评价——以津冀海域为例 总被引:2,自引:1,他引:1
海洋功能区划是海域法确定的海域开发利用的重要依据。本文针对海域开发利用管理的技术需求,采用专家咨询法,确定海域使用分类8个一级类型所包含的30个二级类型的资源耗用系数,构建了海域开发利用强度指数及海域开发利用评价标准,以此为基础形成了基于海洋功能区划的海域开发利用承载力指数,并以津冀海域为例开展了实证评价研究。结果表明:①以海洋功能区划为依据的海域开发利用承载力评价方法可客观地揭示海域开发利用承载力程度。②津冀海域的曹妃甸海域、天津滨海新区海域和黄骅海域开发利用承载力指数分别达到10.30、13.87和10.30,处于承载力较高状态;昌黎海域开发利用承载力指数为7.61,处于承载力适中状态;其余的秦皇岛市区、抚宁县、乐亭县、滦南县和丰南区海域开发利用承载力指数都小于5.0,处于承载力较低状态。 相似文献
998.
Piles are the main building foundation in permafrost regions. Thawing the permafrost foundation would have a negative effect on a pile, and may cause damage to the building. This paper focuses on the effects of negative friction force due to the melt of permafrost, and presents four calculated methods for bearing capacity of a pile. An engineering station was taken as an example, where the lengths of a pile were compared based on four methods. Finally, quick field load tests were carried out, and some meaningful conclusions are presented. Thus, these analytical results can be used to design a pile for permafrost regions. 相似文献
999.
黑龙江省土壤水分常数的空间分布特征 总被引:10,自引:0,他引:10
依据黑龙江省33个农业气象试验站近10年的土壤水分常数资料,综合分析了凋萎湿度,田间持水量,土壤容重的空间变化特征,为进一步客观评价全省土壤水分盈亏状况及进行土壤水分分区奠定基础。 相似文献
1000.
本文针对云南洱源县振戎中学食堂钢钢筋混凝土耗能减振体系,首先建立了耗能减振结构构件的恢复力模型,其次,结合文献[10]提出的“三水准”地震损伤性能目标和文献[11]中的简化设计方法以及ATC-40报告中的能力谱法,对此结构在大震下的地震损伤性能进行了分析和设计验算,最后考察了耗能关振装置对结构损伤性能的控制效果。 相似文献