Transient loading-related settlement of a square foundation on geogrid-reinforced sand     

B. M. Das  A. Maji 《Geotechnical and Geological Engineering》1994,12(4):241-251

Summary Laboratory model test results are presented that determine the effectiveness of using layers of geogrids as reinforcement in sand to reduce the settlement of square surface foundations subjected to transient loading. The model tests were conducted with only one type of geogrid at one relative density of compaction of sand. The maximum intensity of the transient load applied always exceeded the static ultimate bearing capacity of the foundation when supported by unreinforced sand. The settlement reduction factors for various depths of reinforcement have been determined.  相似文献   

三角形量测法在隧道变形监测中的应用研究   总被引：3，自引：0，他引：3  

曾鼎华  张永兴  阴可  陈建功 《水文地质工程地质》2005,32(5):113-115

通过对隧道变形监测中三角形量测法原理、计算公式的分析,认为公式中的三角形三边长度并不是收敛计的读数,两者相差一个收敛计本身的附加长度,这是使监测数据产生误差的原因之一。同时探讨了忽略收敛计附加长度引起的误差对监测结果的影响,并结合工程实例介绍了在实测过程中应注意的问题及误差原因。  相似文献   

Space,Place, Population and Census Analysis in Australia     

Graeme Hugo 《The Australian geographer》2007,38(3):335-357

The Australian Census of Population and Housing is a census of people not places. However, where people live and work can be of major relevance in our search for explaining and understanding their behaviour. This paper argues that the place dimension in the Australian census has not been exploited very effectively in this respect. Three dimensions of the issue are addressed. Firstly, the spatial units commonly used for analysis of census data often are not appropriate to the problem being investigated. The spatial units in the Australian Standard Geographical Classification (ASGC) used for census data rarely represent meaningful social, economic and environmental regions. Secondly, the use of a simple urban/rural dichotomy is criticised as being a very blunt instrument to differentiate settlement types. Thirdly, the relationship between people and place in the census is discussed. While for the most part the census relates people to a single location—their place of usual residence—this is only one of the places with which people regularly interact. It is suggested that there is a need to adopt practices in the census which allow a range of population geographies to be defined. In conclusion it is argued that innovation in the Australian census, especially with the introduction of meshblocks and contemporary methodology and technology in Geographical Information Systems, makes it possible to analyse spatially referenced data in ways that can address these three issues.  相似文献   

Performance of surface footing on geocell-reinforced soft clay beds   总被引：2，自引：0，他引：2  

Sitharam G. Thallak  Sireesh Saride  Sujit Kumar Dash 《Geotechnical and Geological Engineering》2007,25(5):509-524

This paper presents the results of laboratory model tests carried out to develop an understanding of the behaviour of geocell-reinforced soft clay foundations under circular loading. Natural silty clay was used in this study. The geocells were prepared using biaxial polymer grid. The performance of the reinforced bed is quantified using non-dimensional factors i.e., Bearing capacity improvement factor (I_f) and Percentage reduction in footing settlement (PRS). The test results demonstrate that the geocell mattress redistributes the footing load over a wider area thereby improving the performance of the footing. The load carrying capacity of the clay bed is increased by a factor of up to about 4.5 times that of unreinforced bed. From the pressure-settlement responses, it is observed that the geocell-reinforced foundation bed behaves as a much stiffer system compared to the unreinforced case indicating that a substantial reduction in footing settlement can be achieved by providing geocell reinforcement in the soft clay bed. The maximum reduction in footing settlement obtained with the provision of geocell mattress of optimum size placed close to the footing is around 90%. Further improvement in performance is obtained with provision of an additional planar geogrid layer at the base of the geocell mattress.  相似文献   

National and transnational borderlanders’ attitudes towards the security fence between Israel and the Palestinian Authority     

Alon Gelbman  Ofra Keinan 《GeoJournal》2007,68(4):279-291

The subject of the security fence between Israel and the Palestinians in the West Bank has become a major issue in Israel and in the world in the last several years. The main aim of this research is to reveal the attitudes and thoughts about the fence held by local residents living in settlements (borderlanders) in the proximity of a part of the security fence that has already been completed. The research concentrates on the western-Israeli side of the fence, as it aspires to delve into and understand the meaning and implications of the security fence on matters such as personal security, safety of property and freedom of movement, the possibility of maintaining social and economic ties between the two sides and feelings about living in the area in the future. Underlying this research is the transformation occurring in the border area as a result of its closure by construction of the security fence, after many years in which it was open partially. This process has many diverse consequences, some of them contradictory, on the two populations residing near the border in Israel: the majority Jewish population (the national borderlanders), and the minority Arab population (the transnational borderlanders).  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   

圆形板基础下地基强度和变形非线性性状研究   总被引：3，自引：1，他引：3  

应永法  泮威风 《岩土力学》2002,23(2):250-256

采用Drucker弹塑性模型、SAP91非线性有限元程序、Vizi CAD微机有限元前后处理系统计算、分析了轴对称问题，即圆形板情况下，基础板几何尺寸、基础刚度、边界条件、基础埋深对基础沉降量、塑性区开展的影响，结果表明基础沉降随基础几何尺寸增大而增大，随基础刚度、埋深的增大而减小；基础刚度、几何尺寸、埋深的加大都能提高地基承载力。  相似文献   

既有建筑地基基础加固劈裂注浆法在青纸汽运办公楼的应用     

王高旺 《福建地质》2001,20(4):196-200

青纸汽运办公由于部分基础座落在松散的杂填土层上，产生不均匀沉降破坏，通过劈裂注浆加固，建筑物停止沉降，地基土承载力标准值提高了4倍，效果显著。加固劈裂注浆法是治理既有建筑地基基础沉降灾害的有效方法之一。  相似文献   

未来10年我国不同生态区居民点建设占用耕地预测   总被引：1，自引：0，他引：1  

张凤荣  安萍莉 《地理与地理信息科学》2001,17(2):1-4

通过以生态区为单位分析 ,预测 2 0 0 0～ 2 0 10年 10年间人口增长和居民点建设用地需求及其占用耕地面积。研究表明 :全国未来 10年人口净增加 12 6 96万 ,因人口增长造成的居民点建设用地需求 12 6 6 571hm2 ,其中占用耕地达 6 4 5545hm2 。耕地减少最多的是淮北平原、华北平原、长江下游平原、四川盆地丘陵、长江中游平原、闽粤丘陵平原、汾渭谷地等平原区。  相似文献   

太原盆地东南部农村聚落空心化机理分析   总被引：83，自引：0，他引：83  

程连生  冯文勇  蒋立宏 《地理学报》2001,56(4):437-446

在分析和界定空心化聚落的基础上 ,用雷达模型揭示了空心化聚落的激发因素和潜育环境 ;依据相对空化率和绝对空化率区位商构成 2× 2阶矩阵 ,将该区聚落划分为 4个空心化等级 ;并利用家庭预算曲线和地价理论 ,探讨了空心化聚落的成因机制 ;在研究聚落空间消长和应力状况的前提下 ,提出了反映聚落空心化的 5种过程模型 ,最后探讨了制止聚落空心化的若干措施。  相似文献