CFG桩复合地基问题   总被引：12，自引：0，他引：12  

李椋京  化建新 《岩土工程技术》2004,18(6):271-274

对CFG桩复合地基设计、施工和检测问题进行了探讨,提出了CFG桩复合地基亟待研究的问题.  相似文献   

Topographic and climatic influences on accelerated loess accumulation since the last glacial maximum in the Palouse, Pacific Northwest, USA     

Mark R. Sweeney  Alan J. Busacca  David R. Gaylord 《Quaternary Research》2005,63(3):574-273

Topographic and climatic influences have controlled thick loess accumulation at the southern margin of the Palouse loess in northern Oregon. Juniper and Cold Springs Canyons, located on the upwind flank of the Horse Heaven Hills, are oriented perpendicular to prevailing southwesterly winds. These canyons are topographic traps that separate eolian sand on the upwind side from thick accumulations (nearly 8 m) of latest Pleistocene to Holocene L1 loess on the downwind side. Silt- and sand-rich glacial outburst flood sediment in the Umatilla Basin is the source of eolian sand and loess for the region. Sediment from this basin also contributes to loess accumulations across much of the Columbia Plateau to the northeast. Downwind of Cold Springs Canyon, Mt. St. Helens set S and Glacier Peak tephras bracket 4 m of loess, demonstrating that approximately 2500 g m⁻² yr⁻¹ of loess accumulated between about 15,400–13,100 cal yr B.P. Mass accumulation rates decreased to approximately 250 g m⁻² yr⁻¹ from 13,100 cal yr B.P. to the present. Tephrochronology suggests that the bulk of near-source Palouse loess accumulated in one punctuated interval in the latest Pleistocene characterized by a dry and windy climate.  相似文献   

土工格栅加筋垫层用于处理特殊地基     

郭力群  马时冬 《岩土工程技术》2005,19(3):109-112

某地两幢拟建于软土地基上的建筑物,原设计均采用PHC管桩基础。在桩基施工过程中分别发现软基中有大量孤石和条石(古码头遗址),桩基无法施工。经多方论证,最后采用水泥搅拌桩复合地基配合土工格栅加筋垫层的处理方案。其中一幢建筑已竣工,经现场荷载试验和沉降观测检验,地基承载力和沉降完全满足工程要求,且降低了造价。  相似文献   

Structural characteristics of zeolite/TiO-2 composite and photocatalysis of toluene degradation   总被引：1，自引：0，他引：1  

明彩兵  吴平霄 《中国地球化学学报》2005,(4)

1Introduction Researchontheapplicationofnaturalminerals(zeolite,montmorillonite,etc.)inenvironmentalpro tectionisattractinggreatattentionofmoreandmorere searchers(WuPingxiaoetal.,2001;Suhasetal.,2000).Asthenaturalmineralshavelargenumbersof micro poresandbigsurfaceareas,thezeolite/TiO2compositephotocatalystcanbepreparedbycombining TiO2withzeolite.Nucleus formationfreeenergyof TiO2crystaldecreasesinamulti phasesystemofzeo lite,whichhelpsformnanometerTiO2crystalanden richstructuralhydroxyl;op…  相似文献   

路堤荷载下CFG桩复合地基沉降分析          下载免费PDF全文

詹云刚  纪淑鹏 《探矿工程》2005,32(4):4-6,14

分析了路堤荷载下CFG桩复合地基的变形机理，根据假定的沉降模式及桩侧摩阻力分布形式，推导出了考虑桩-土-褥垫层共同作用的简化沉降计算公式，结果与试验数据吻合较好。  相似文献   

Formulating a General Spatial Segregation Measure*     

David W. Wong 《The Professional geographer》2005,57(2):285-294

Most traditional segregation measures, such as the index of dissimilarity D, fail to distinguish spatial patterns effectively. Previously proposed spatial measures modifying D suffer from several shortcomings. This article describes a general spatial segregation index based upon the concept of composite population counts, which are derived from grouping people in neighboring areas together to account implicitly for spatial interaction of groups across unit boundaries. The suggested spatial index can overcome the disadvantages of previous indices and can assess the spatial extent of the segregated clusters. The results offer a more comprehensive depiction of spatial segregation of a region.  相似文献   

复合地基垫层的减振作用分析     

王凤池  朱浮声  林勇 《世界地震工程》2004,20(3):109-113

从垫层桩基的减振机理出发，分析了垫层桩基和复合地基的等效性，提出了复合地基的减振机理和减振动力模型。复合地基的减振性能主要体现在减小振幅、粘滞阻尼耗能和摩擦耗能上。根据复合地基的减振机理，可把基础和垫层简化为多自由度的质、阻、弹振动体系，同时考虑滑动摩擦作用。最后，提出了按减振思想设计和施工复合地基的要求。  相似文献   

地震数据处理解释一体化在隐蔽油气藏勘探中的应用     

ZhouJinming 《应用地球物理》2004,1(2):95-102

Nowadays, it becomes very urgent to find remain oil under the oil shortage worldwide.However, most of simple reservoirs have been discovered and those undiscovered are mostly complex structural, stratigraphic and lithologic ones. Summarized in this paper is the integrated seismic processing/interpretation technique established on the basis of pre-stack AVO processing and interpretation.Information feedbacks occurred between the pre-stack and post-stack processes so as to improve the accuracy in utilization of data and avoid pitfalls in seismic attributes. Through the integration of seismic data with geologic data, parameters that were most essential to describing hydrocarbon characteristics were determined and comprehensively appraised, and regularities of reservoir generation and distribution were described so as to accurately appraise reservoirs, delineate favorite traps and pinpoint wells.  相似文献   

Effect of ‘species weighting’ on conservation status evaluation: a case study with light-traped adult caddisflies (Insecta: Trichoptera)     

Dnes Schmera 《Limnologica》2004,34(3):274-278

Wildlife conservation requires methods to express the conservation status of assemblages in order to identify those of importance. Expressions of diversity and a number of different conservation status indices are widely used techniques for assessing assemblages. Some of these indices are based on species lists, while others use abundances. In this study, the conservation statuses of 21 light-traped adult caddisfly assemblages were compared using species lists and abundance data. The results showed that the assessment based on species list provided a higher conservation status than that based on species abundances. Consequently, indices incorporating species abundances were not comparable with indices using only species lists. The difference between the two measures might be derived from the unequal weighting of species categories. In conclusion, incorporating species abundance reduces sampling method bias and increases the precision of the conservation status evaluation.  相似文献   

云母复合材料板的合成研制     

黄和明  徐文炘  郭陀珠 《矿产与地质》2004,18(6):594-597

选择了云母作为纤维矿物材料替换石棉，填料选用叶蜡石、方解石和方镁石等矿物，进行云母复合材料板合成，并详细解析分别由云母、云母 方解石、云母 叶蜡石 方解石、云母 方解石 叶蜡石 方镁石等一元、二元、三元和四元等材料合成的复合材料板的物理性质和机械性能，得出了以多元矿物材料合成的制品的质量优于单元矿物材料合成的制品，以四元矿物材料合成的云母复合材料板可任意切割，复合材料的厚度可达到5mm左右。  相似文献