路面基层压实度现场测试中的非理想因素分析--以广东西部沿海高速公路新会段为例     

史玉金  蔡鹤生 《地质科技情报》2002,21(1):110-112

通过对广东西部沿海高速公路路面基层现场压实度检测过程的详细观察，并在不同的条件下反复进行试验、分析比较，找出了影响压实度现场检测精度的主要非理想因素，即标准砂密度、试样含水量和路面基层平整度，并提出了解决方法。  相似文献   

高速公路砂井地基固结度时空变化规律探讨     

周爱国  刘晓  刘增贤 《水文地质工程地质》2002,29(1):28-30,34

软基固结度时空变化规律的研究对解决高速公路软基沉降预测问题具有十分重要的意义。本文在讨论固结度时空变化的实质与计算方法的基础上，结合京珠高速公路广珠段某软基试验资料，初步探讨了高速公路砂井地基固结度的时空变化规律，特别提出固结的滞后效应及其对固结沉降曲线形态的影响，并简要讨论了砂井直径和间距对固结度的影响，认为软基沉降中地下水微观动力学过程的研究将有助于揭示固结度时空变化规律。  相似文献   

砂体及其研究价值   总被引：1，自引：0，他引：1  

田兆成  姜秀萍 《吉林地质》2002,21(4):19-25

本文论述了砂体的意义，砂体的研究价值，砂体的分类，并从多方面阐明了砂体在可地浸砂岩型铀矿找矿工作中的作用。抛砖引玉，力图推进砂体的研究工作，为可地浸砂岩型铀矿的找矿工作服务。  相似文献   

风成沙系统去除官厅水库水中化学需氧量的效果   总被引：2，自引：0，他引：2  

陈明  张前进  刘晓端  张玲金  周兴志 《岩矿测试》2002,21(3):195-198

试验表明 ,在水力负荷为 1 .0～ 1 .5m/d ,沙层湿干时间比为 1 2∶1 2 (h)条件下 ,风成沙污染水处理系统稳定后对化学需氧量 (CODCr)平均去除率约为 61 % ,CODCr<1 5mg/L ,优于《地表水环境质量标准 (GHZB1 -1 999)》规定的Ⅰ类标准。影响处理效果的因素主要有进水水质、沙层湿干时间比、水力负荷和滤层厚度等  相似文献   

松辽盆地舍伯吐地区第三系砂体层间氧化-还原过渡带发育特征及其含铀性   总被引：2，自引：0，他引：2  

李国宽  张景训  桑吉盛  张振强 《铀矿地质》2002,18(6):335-339

松辽盆地是上叠于海西褶皱带基底之上的中新生代陆相沉积盆地。舍伯吐地区位于松辽盆地西南部，区内上第三系松散堆积层赋存有3层稳定的砂体。砂体中均发育有不同规模的区域性层间氧化带。经钻探揭露，榆树屯地段Ⅱ层砂体的层间氧化-还原过渡带比较典型，并有铀和钼的次生富集，这一发现为松辽盆地找矿工作的突破展现了良好的前景。  相似文献   

铁路沿线灾害性天气监测、预测、预警系统   总被引：3，自引：0，他引：3  

叶文军  刘红光等 《沙漠与绿洲气象(新疆气象)》2001,24(6):25-27

针对铁路三防（防风，防沙，防洪）的需要，结合大风监测系统建设的实际，对恶劣天气气候条件下，如何保障列车运行安全进行了探讨，并提出铁路沿线灾害性天气监测，预测，预警系统。  相似文献   

南京砂的液化与判别   总被引：9，自引：0，他引：9  

黄永林 《世界地震工程》2001,17(1):69-74

南京砂是一种以片状颗粒成分为主的粉细砂，与土动力学试验中常用的圆形颗粒标准石英砂有一定的差别。片状颗粒成分使得南京砂具有各向异性的性质，其水平向强度小于垂直向强度。因此，在同样的标贯击数下，南京砂比标准砂易于液化，在采用基于标准砂的研究结果作为液化判别标准时，可能会高估这种砂的抗液化能力。文章在总结南京砂液化研究资料的基础上，阐明了南京砂液化的特点，提出了南京砂液化的判别式。  相似文献   

Textural attributes, mineralogy and provenance of sand dune fields in the greater Al Ain area, United Arab Emirates     

Mohamed M. Abu-Zeid  Ashraf R. Baghdady  Hassan A. El-Etr 《Journal of Arid Environments》2001,48(4):475

Sand dunes and interdune sediments around Al Ain city have markedly high carbonate contents which increase towards Jabal Hafit mountain and the Arabian Gulf coast. The dunes are composed predominantly of well-sorted fine sands, consisting of unstrained quartz and carbonate grains together with minor proportions of chert and feldspars. Scanning electron microscope (SEM) examination reveals that quartz grains display various mechanically- and chemically-formed surface textures. The heavy minerals are dominated by opaques and pyroxenes with minor tourmaline, garnet, rutile, epidote, monazite, zircon, hornblende and staurolite.Interdune sediments consist of fine and very fine, poorly- to extremely poorly-sorted sands together with small concentrations of gravel, silt and clay. The light sand fractions compositionally resemble those of dunes but contain, in addition, gypsum, anhydrite, halite and celestite. Percentages of pyroxenes are higher whereas those of zircon, tourmaline and rutile are lower than in dunes. X-ray diffractometry reveals that the clay fractions consist solely of palygorskite. Generally, interdune sediments are much less mature texturally and mineralogically than dune sands; the maturity of both types of sediments decreases toward the NE of the study area.Sand dunes in the various districts of the greater Al Ain area are genetically related. Also, there is a partial genetic relationship between the dunes and interdune sediments; both are mainly multicyclic. Their major parts were brought mainly by the dominant north-west (El Shamal) winds from older dune fields in other localities in U.A.E., Qatar and El-Rub El-Khali. Local contributions to the dune fields from Jabal Hafit mountain, the Oman Mountains and the calcareous coast of the Arabian Gulf were, in cases, significant. Also, authigenesis by groundwater under highly evaporitic conditions played a major role in the formation of interdune sediments through the genesis of the clay and some nonclay minerals.  相似文献   

A darkling beetle population in West Texas during the 1997–1998 El Niño     

Richard J. Deslippe  Jesus R. Salazar  Yu-Jie Guo 《Journal of Arid Environments》2001,49(4):711

We examined the abundance and distribution of Eleodes extricata (Tenebrionidae) in a semi-arid region of West Texas. During the 2-year study, climatic conditions were extreme but opposite, with 1997 being unusually wet and mild, and 1998 being unusually dry and hot. These conditions were associated with striking differences in the population structure of the beetles. Under identical pitfall-sampling efforts, we captured 1562 and 671 individuals in 1997 and 1998, respectively. Capture rates were lowest in grassland, and highest in sand shinnery oak, and within the latter, they were lowest in blowouts, intermediate along the edges of blowouts, and highest under vegetative cover. Sex ratios were consistently female-biased, and the degree of bias increased from spring through fall in both years. These increases were more pronounced in 1998, with the sex ratios of early and late sampling periods differing by over four-fold, from 1·15 to 5·00. Females were heavier than males, and the dry masses of both sexes increased from spring though fall in both years. As with sex ratios, these increases were more pronounced in 1998. Only the largest beetles survived the drought, illustrating how extreme conditions can exert especially strong directional selection, and affect sex ratios in populations with sexual size dimorphism.  相似文献   

泥浆含砂率对桩基质量的影响     

宋明智  许谷星 《江西地质》2001,15(4):301-304

本文通过对泥浆中颗粒的沉降特性分析，从量上得出泥浆性能对泥浆中颗粒的悬浮携渣能力。泥浆是一流变性的流体，对泥浆性能的把握，应综合考虑，而不偏向于某个指标。提出了在实践中对泥浆的正确使用和泥浆性能取用的建议。  相似文献