黄土场地大型浸水试验湿陷沉降预测的Elman方法     

韩晓萌  王家鼎  谷天峰  薛建功 《地下水》2008,30(6):111-113

收集郑西高速铁路湿陷性黄土场地现场大型浸水试验资料,运用MATLAB建立了黄土场地湿陷沉降的Elman神经网络预测模型。通过对样本的训练和预测,表明该模型预测的结果与实际湿陷沉降比较接近,是一种比较理想的预测方法。  相似文献   

盐度对冠瘤海鞘幼体附着与变态的影响   总被引：2，自引：0，他引：2       下载免费PDF全文

冯丹青  柯才焕  周时强  黄英 《海洋科学》2003,27(1):42-46

通过盐度梯度实验检验了盐度对冠瘤海鞘（Styela canopus)幼体附着和变态的影响。在盐度10－40范围内，低盐度抑制幼体变态，高盐度促进其开始变态及完全变态，但盐度40不促进完全变态。低盐度可使幼体附着（除盐度10抑制附着），高盐度促进附着，但盐度达40不促进附着。  相似文献   

Improvement of estuarine marine clays for coastal reclamation using vacuum-applied consolidation method     

Young-Suk Song  Tae-Hyung Kim   《Ocean Engineering》2004,31(16):23-2010

Consolidation occurs in estuarine marine clays for coastal reclamation by dissipation of the excess pore pressure, which is induced by increasing the total overburden stress during conventional mechanical surcharging. The excess pore pressure can be decreased usually by the use of several construction methods such as sand drain and paper drain. Besides the drain methods, vacuum can also be used in the soil mass to consolidate the estuarine marine clays by decreasing the pore pressure as well as increasing the effective stress.The study on vacuum consolidation is devoted so far mainly for laboratory model tests or numerical analysis in Korea. Recently, an instrumentation system was applied to manage the vacuum-applied consolidation on a field, in which a sewage disposal plant was constructed. While vacuum was applied, the behaviors of estuarine marine clays such as the settlement, lateral deformation and pore water pressure have been investigated precisely. The behavior of estuarine marine clays during vacuum-applied consolidation shows some difference from the behavior of estuarine marine clays in the case of conventional preloading. A principal difference is that the lateral deformation corresponding to settlement is smaller than before vacuum application even though the surcharge height has been increased.  相似文献   

Reliability of Conventional Settlement Evaluation for Circular Foundations on Stone Columns     

H. A. Elshazly  D. H. Hafez  M. E. Mossaad 《Geotechnical and Geological Engineering》2008,26(3):323-334

The unit cell idealization has been long adopted in the settlement prediction of stone column-reinforced soils. This paper tests the accuracy of this modeling concept against trusted settlement values of engineering foundations. It is believed that in order to bestow the outcome of this study adequate generality different soil properties and foundation geometries need to be considered. It was, nevertheless, found impracticable to collect field settlement records for all the analyzed cases. The authors, therefore, appealed to the back analysis concept to construct a reliable mathematical model, calibrated against settlement records of full-scale field load test. This model, which is capable of reproducing the real field settlements, is then employed as a generic tool to obtain trusted settlement values for a variety of cases with essential geometrical similarity. The investigation revealed that the unit cell analysis may, in some cases, lead to erroneous estimation for the settlements of foundations with limited extents. Correction factors, dependent on the treated soil properties as well as the foundation size, are introduced.  相似文献   

遥感技术在聚落研究中的应用——以巢湖“九龙攒珠”移民村落为例     

张靖华  陶承洁  吴从宝 《国土资源遥感》2008,19(4):58-60

近年来,遥感技术在城市遗址观测、地下文物勘查工作中发挥的作用愈来愈大,相比之下,在古代建筑和聚落研究领域则应 用较少。本文以巢湖北岸移民村落的发现、研究为例,试论遥感技术在古建筑及聚落研究领域的应用前景。  相似文献   

决策树分类算法在姜寨一期聚落遗迹分类中的应用研究   总被引：1，自引：0，他引：1  

陈济民  黄家柱  毕硕本  闾国年  裴安平 《测绘科学》2006,31(4):78-80

通过对数据挖掘基本分类算法的总结、分析,以及建立姜寨遗址空间数据库,以姜寨一期聚落中的土坑墓、房屋等遗迹作为研究对象,分别提取该遗迹的面积与方位角等空间矢量特征信息等,运用决策树分类算法,挖掘出了姜寨一期聚落的遗迹分类规则,为聚落考古学中单遗址聚落的空间布局和内部结构的研究提供了一种新的研究思路与实现方法。  相似文献   

预测工后软土地基沉降   总被引：2，自引：0，他引：2  

朱玉美  胡伍生 《现代测绘》2006,29(2):9-10

本文简要叙述沉降观测在软土地基施工中的重要性,并提出了基于神经网络的高速公路工后沉降预测方法。结合工程实例运用MATLAB工具箱函数建立网络模型,选择合适的训练函数,使其训练精度和速度达到最优化。  相似文献   

Exposing the urban continuum: implications and cross-comparison from an interdisciplinary perspective     

Johannes H. Uhl  Hamidreza Zoraghein  Stefan Leyk  Deborah Balk  Christina Corbane  Vasileios Syrris 《International Journal of Digital Earth》2020,13(1):22-44

ABSTRACT

There is an increasing availability of geospatial data describing patterns of human settlement and population such as various global remote-sensing based built-up land layers, fine-grained census-based population estimates, and publicly available cadastral and building footprint data. This development constitutes new integrative modeling opportunities to characterize the continuum of urban, peri-urban, and rural settlements and populations. However, little research has been done regarding the agreement between such data products in measuring human presence which is measured by different proxy variables (i.e. presence of built-up structures derived from different remote sensors, census-derived population counts, or cadastral land parcels). In this work, we quantitatively evaluate and cross-compare the ability of such data to model the urban continuum, using a unique, integrated validation database of cadastral and building footprint data, U.S. census data, and three different versions of the Global Human Settlement Layer (GHSL) derived from remotely sensed data. We identify advantages and shortcomings of these data types across different geographic settings in the U.S., which will inform future data users on implications of data accuracy and suitability for a given application, even in data-poor regions of the world.  相似文献   

云南哀牢山的梯田景观   总被引：4，自引：1，他引：4  

陆玉麒 《热带地理》1994,14(2):180-185

云南哀牢山区哈尼族人创造的独具特色的热带山区梯田景观，在与自然环境的协调过程中，巧妙地解决了农耕中的关键要素水分与肥料，创造了较高的粮生产水平，并以聚落分布的适中高度，均衡建构中介，最终内化为一种独特的文化形态，自然与人文在此所形成的高度协调关系，无疑具有重要的理直学研究意义。  相似文献   

山区边坡工程监测的探讨     

赵瑞  麻德明  张红杰  邓梨梨  康新亮  苏家群 《北京测绘》2007,(3):54-56

以某煤矿边坡监测为例,较为详细地论述了在边坡监测中的布网方案、观测方法以及监测结果分析等问题。在位移观测时采用了改进的视准线法,并对该方法的精度进行了分析,结果证明其精度可以满足二等变形观测的要求。  相似文献