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水泥粉煤灰碎石桩(CFG桩)复合地基在高层建筑地基处理中的应用 总被引：1，自引：0，他引：1
随着高层建筑工程的飞速发展,地基处理由于相对低廉的工程造价在高层建筑中的应用越来越广泛。水泥粉煤灰碎石桩(CFG桩)复合地基由于充分利用桩间土和桩的特有优势,目前已成为应用最为普遍的地基处理技术之一,而且具有极好的应用前景。本文通过实例工程,介绍CFG桩在高层建筑地基处理中的应用技术。 相似文献
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通过工程实例,介绍CFG桩在大型油罐地基局部处理中,既有效提高软弱地基强度,又最大限度保持不同地基变形协调一致的处理方法.针对油罐体型的特殊性,采用了沿油罐圆心环形布桩,并且根据不同地段地基土性质的纵横向差异采用不等距布桩的方案.复合地基处理效果理想,达到了预期的设计目的,为类似工程的地基处理提供了一种新的设计理念,供类似工程参考. 相似文献
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通过对某循环水车间病害地基处理实例的分析总结,介绍了石灰桩的加固机理和优点,以及处理小型病害地基的技术方法。 相似文献
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Roughness of successively developed gravel surfaces in flume experiments is investigated using laser scanned elevation fields. Scaling behavior of these surfaces is studied using structure functions. The results show that all surfaces exhibit good scaling behavior for two scaling regions. Multifractal analysis based on singular measures is then conducted for the two scaling regions, respectively. The relatively smaller scaling region characterizing subgrain scale roughness exhibits evident nonstationarity and intermittency. In contrary, the measures for the larger scaling region characterizing the spatial distribution of grains are more stationary and less intermittent than the measures for the subgrain scaling region. 相似文献
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岩浆岩砾石磨圆度地质意义的研究 总被引：1，自引：0，他引：1
定量地质学的兴起促进了地球科学的快速发展,但是国内外对砾石磨圆度与搬运距离之间定量关系的研究长期以来没有明显的进展。本次研究通过对永定河、碓臼峪、滦河和大石河四条河流进行系统的野外考察,从河流的出山口开始向下游设定考察点,详细描述各考察点砾石的磨圆度、粒度特征并进行统计分析,对岩浆岩砾石磨圆度与搬运距离的定量关系以及磨圆度的影响因素进行了研究。研究发现,岩浆岩砾石的磨圆度随着搬运距离的增大而变好,在搬运的初期变化最快,而后逐渐缓慢下来,最终磨圆度趋于稳定。岩浆岩砾石由棱角状变为次棱角状一般需要搬运3~6 km,由次棱角状变为次圆状一般要搬运12~21 km,圆状砾石大量出现至少要搬运22~31 km。砾石的磨圆度受搬运距离、母岩成分、粒度和破碎作用的影响。棱角状、次棱角状砾石容易被磨蚀,在搬运初期转化为次圆状、圆状,而圆状砾石不易磨蚀达到极圆状;岩浆岩砾石磨圆速度比石英快,比石灰岩慢;相同母岩成分的砾石,粗粒砾石比细粒砾石磨圆快;破碎作用则会降低砾石的磨圆度,使部分砾石呈现出与搬运距离不协调的磨圆特征。 相似文献
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Don G. Wyckoff 《Geoarchaeology》1993,8(1):35-58
Alibates silicified dolomite is one of the principal knappable lithic materials indigenous to the Southern High Plains. Prehistorically, this material was extensively quarried along the Canadian River in Potter County, Texas. Some of these quarries are preserved in what is now the Alibates National Monument. Archaeologists working in Oklahoma traditionally interpret artifacts of Alibates silicified dolomite as evidence for long distance trade. However, a survey of three transects across the Canadian's valley in western Oklahoma reveals the persistent, but minor, presence of Alibates clasts in gravel deposits. Thirty-nine gravel exposures yielded 1365 clasts of the dolomite. The abundance, size, shape, and knappability of this material is comparable to most flakes and implements found on western Oklahoma archaeological sites, especially those of prehistoric and protohistoric Plains Villagers. © 1993 John Wiley & Sons, Inc. 相似文献
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本文对我国的ＭＢ－２型和美国的ＴＲ－２型卵石推移质采样器的模型的水力特性和采样效率进行了对比试验研究。得到ＭＢ－２的水力效率为０．９１，ＴＲ－２的水力效率为１．０４；仪器置入水中后水流的紊动强度ＴＲ－２比ＭＢ－２大。ＴＲ－２的采校效率平均是ＭＢ－２的１．８４倍，ＴＲ－２的采样效率方差平均是ＭＢ－２的１．６７倍，即前者的采样效率比后者高，但其采样效率的稳定性比后者差。文中还给出了两种仪器的采样效率η 相似文献
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Data on the fabric properties of gravels have been collected at 10 locations over a distance of 27 km from the Chakki River — a braided channel of the Beas River system. The imbrication of AB-planes reveals a close correspondence with the channel direction; the deviations seldom exceed 30°. Increase in sinuosity and the existence of subsidiary channels contribute, at some locations, to larger deviations. Imbrication directions tend to be modified because of the influence of local channels which develop temporarily on the bar surfaces.A current-normal mode exists for the A-axis orientation data. Bimodal distributions are recognised and attributed to shifting flow conditions. Variance values are low for both the imbrication and A-axis data. The range in mean values of the dip of AB-planes is between 22.6° and 37.6° with s = 8° to 14°. The mean values of plunge of the A-axis vary from 2.9° to 13.2° with s = 3.4° to 12.69°. There is a marked decrease in plunge of the A-axis in the downstream direction in the Chakki River.A particle size versus orientation approach indicates that, irrespective of size, there is a strong upcurrent imbrication. Longitudinal alignment of particles in the smaller size intervals is not supported by the data obtained in this study. A particle shape versus orientation approach reveals that the A-axis orientation is not dependent on particle shape. The A-axis fabric patterns of both tabular and bladed clasts show a peripheral circular arrangement of the maxima, the bisectrix of which points in a current-normal direction. Orientation patterns do not reflect any control in terms of the lithic composition of clasts. 相似文献
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从北京市丰台地区第四系潜水含水层的地层岩性结构入手,分析了传统供水管井成井工艺存在的问题,详细研究介绍了孔壁坍塌填砾法成井工艺在实际水井工程项目中的成功应用,取得了较好的增加水井出水量的效果。 相似文献
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利用碎石屏障阻断非饱和带毛细上升为土壤盐渍化改良提供了新思路.为了研究碎石屏障对盐渍化土壤改良的可行性以及碎石层结构和埋深对改良效果的影响,在河套灌区西部杭锦后旗典型盐渍化分布区建立试验地,设置了7组不同碎石屏障处理工艺开展土壤盐渍化改良试验,对试验地40 cm深度的土壤盐分、pH、阳离子交换量、交换性钠百分率等参数进行了为期一年的监测和分析.结果表明,7组不同处理中,埋设深度为60~80 cm,利用颗粒直径为1 cm和3 cm的碎石按上细下粗的结构分两层铺设的处理方法改良效果最佳;从表层到40 cm深,土壤EC值平均下降55.9%.较大的碎石屏障埋深,上细下粗的铺设方式,可提高下层碎石孔隙度,并在非饱和带深处切断毛细管,从而有效降低土壤毛细上升高度,抑制深层土壤中的盐分上移"返盐",改良效果较好. 相似文献