Stabilization of lateritic soils with phosphoric acid   总被引：1，自引：0，他引：1  

J. Medina  H. N. Guida 《Geotechnical and Geological Engineering》1995,13(4):199-216

Summary This paper describes a laboratory study on the stabilization of lateritic soils with phosphoric acid-H₃PO₄. This method is most promising for road and airport pavement construction in tropical regions where fine textured lateritic soils (red clays and silts) occur over large areas. The iron and aluminum phosphates formed are hard and insoluble. The main source of iron is free iron oxide, and the aluminum sources are free aluminum oxide, exchangeable cations and clay minerals (hydrated aluminum silicates). Four different soil samples were studied, but the most comprehensive study was carried out with a lateritic soil evolved from weathered basaltic bedrock. The variables of the test specimens were: percentage of acid, moulding water content, compaction energy, and curing time. Strength tests performed were the axial or unconfined compression test and the indirect tensile or diametrical compression test. With 5% of phosphoric acid to dry weight of soil, values of compressive strength around 4.0 MPa were obtained after 28 days curing.  相似文献   

遥感图像中城市道路信息的自动识别与制图     

高芳琴  吴健平 《测绘与空间地理信息》2001,24(3):27-29

遥感图像中的地物自动识别一直是图像处理中的研究热点,本文在彩红外航空图像中计算机自动识别提取城市道路上做了一些尝试,将形状指数作为光谱分类后的后处理,并通过人机交互修正分类结果.提取后的道路信息将通过自动制图功能形成矢量格式的地理底图.系统采用VC++6.0语言设计完成.  相似文献   

新疆奎赛段公路工程地质问题及重要工点地质评价     

陆关祥  腾志宏  郝建荣 《西北地质》2001,34(3):40-46

采用彩色红外航空像片，遥感图像处理与野外实地考察相结合的综合研究，详细解释了新疆奎赛公路段的各种不良工程地质问题，并进行了重要工点的水文地质工程地质评价，为我国西部开发过程中，迅猛发展的工程项目的遥感质量调查及工程地质评价提供了科学的参考资料。  相似文献   

Towards understanding the behaviour of naturally-occurring road construction materials     

D. G. Toll 《Geotechnical and Geological Engineering》1991,9(3-4):197-217

Summary Naturally-occurring road construction materials generally contain a greater amount of fines, and the fines have a higher plasticity than traditional materials such as a crushed rock aggregates. This makes their behaviour more difficult to understand and predict since soil suction and fabric become important controlling factors. The concepts of suction and fabric are outlined, and their role in controlling the behaviour of road construction materials is illustrated by a fundamental laboratory study of a lateritic gravel and two calcrete gravels. These materials have successfully been used as road base construction materials in low-volume bituminous-surfaced roads in Kenya and Botswana. It is concluded that the presence of fines can be an advantage, since they allow significant suctions to develop and also reduce the permeability.  相似文献   

车辆导航系统中地图匹配新算法   总被引：2，自引：0，他引：2  

张振辉  崔铁军  姚慧敏 《海洋测绘》2006,26(2):55-58

根据网格思想将道路网络进行分块并融合GPS所提供的定位数据,利用车辆行驶的位置、方向和实际道路网络的拓扑特性,提出一种快速实用地图匹配算法。使GPS数据实时地与G IS地图数据匹配,有效地提高车辆导航的定位精度。  相似文献   

基于WMS的公路交通信息发布系统     

王延亮  储晓雷 《测绘工程》2009,18(6):7-10

采用WMS将公路交通专题地理数据与测绘框架地理数据进行集成与整合，实现跨行业和跨区域的空间地理数据的共享交互操作，并详细阐述系统的整体设计思路、系统架构及关键技术，最后对采用WMS在其它行业的应用进行展望。  相似文献   

用改进的剖面匹配算子提取高分辨率遥感影像上带状道路     

林祥国  张继贤  刘正军 《测绘科学》2009,34(4)

剖面匹配在道路提取中得到了广泛的应用,但现有的相关文献中普遍利用数学模型模拟道路轨迹、利用最小二乘剖面匹配的结果进一步修正数学模型预测的道路点的方法,这种方法与实际的路况有较大的差别。本文中,用户初始化后获得道路的起始点、前进方向、道路的宽度和模板剖面。通过将模板剖面沿道路前进方向平移和旋转生成一系列目标剖面,求目标剖面与模板剖面的灰度差的平方和,在求平方和时给剖面的道路部分更多权重,最小的平方和对应的目标剖面的中点为最精确的道路点,迭代上述步骤追踪道路轨迹。经试验证明,改进的剖面匹配算子是一种稳健高效的道路追踪算法。  相似文献   

一种基于感知分组和结构特征的道路交叉口识别方法     

蒙艳姿  徐柱  刘国祥  蔡国林 《测绘科学》2010,35(4):106-108,99

为了能从矢量地图中准确、快速地识别道路交叉口,本文将感知分组方法与道路交叉口的典型结构特征结合,提出了一种基于感知分组和结构特征的道路交叉口识别方法。为检验算法的有效性,选取两块典型区域即简单道路网和复杂道路网进行实验分析。结果表明,该算法能快速、准确地识别道路交叉口,且具有良好的稳定性和灵敏性。  相似文献   

10m级分辨率卫星影像道路语义模型研究   总被引：1，自引：1，他引：0  

王林  秦其明 《测绘科学》2009,34(3)

道路模型是遥感影像自动/半自动道路提取中重点研究的内容。本文首先介绍了传统的影像道路模型并指出其中不足,从语义的角度阐述了建立道路语义模型的必要性,概述了10m级分辨率卫星遥感影像道路的表现特征,分析了遥感影像道路提取涉及的各层次语义信息,建立了面向10m级分辨率卫星遥感影像的道路语义模型,详细阐述了语义模型的实现过程。将语义模型应用于笔者开发的遥感影像道路提取系统,通过新疆阿图什Spot5多光谱遥感影像道路提取试验,验证了道路语义模型的有效合理性。  相似文献   

Scale-free Structure of Town Road Network in Southern Jiangsu Province of China     

SU Weizhong YANG Guishan YAO Shimou YANG Yingbao 《中国地理科学(英文版)》2007,17(4):311-316

From the viewpoint of Graph Theory this paper builds a town road network graph of regional scale, and proposes numerical vertex degree (Di), rank vertex degree (Dr) and population size vertex degree (Dp) on the base of vertex degree (D). Then the indicators of Di, Dr, Dp and mathematical statistics methods are applied to investigating scale-free structure of town road networks in the southern Jiangsu Province. The results show that the distribution of Di does not exhibit scale-free properties, but Dr and Dp do. Additionally the correlation coefficient between Dp and Di is only 0.569, but the spatial correlation between Dp and Dr is very evident on the base of correlation analysis and spatial analysis of GIS. The mutual mechanism between Dp and Dr spatially represents a "Core-Belt" model of town development of regional scale. The town development model is open and clustered, and beneficial to both economic development and ecological protection. And then we suggest that Suzhou City, Wuxi City, Changzhou City and Wujin City control towns' high-density pattern by conducting centralization and consolidation policies, and properly controlling and planning higher rank roads; whereas Nanjing City, Zhenjiang City, Jintan City and Liyang City must strengthen the development of towns along higher rank roads.  相似文献