山区公路测设长度综合变形问题的研究     

刘传志 《测绘工程》2007,16(4):60-62

在分析公路控制测量长度综合变形来源、允许数值及国家统一坐标系统适用程度和范围的基础上,结合山区公路测量的特殊性,以贵州省板坝至江底公路某合同段坐标系选择为例,提出了山区公路测量坐标系选择方法,能较好地满足工程实际需求。  相似文献   

北京市建设项目竣工测量数据库研究与建立   总被引：1，自引：1，他引：0  

刘忠卿  秦学秀  任海英 《北京测绘》2007,(4):6-8,27

在分析空间数据库技术和ArcSDE数据存储技术的基础上,探讨了如何建立竣工测量成果数据库。对数据库结构和数据加工工艺进行了详细分析和说明。该数据库的建立可实现城市规划建设项目监督测量成果的计算机存储、管理和共享,有效提高竣工测量数据的利用率。  相似文献   

一种邻接区域平面元融合的桥面分割方法     

张兴岩  李琦  梁栋  蒲洁 《大地测量与地球动力学》2022,42(8):863-869

针对桥梁点云的桥面分割问题,提出一种邻接区域平面元融合的桥面分割方法。首先对点云进行体素化处理获得体素点云,利用超体素空间和法线约束准则进行桥梁点云过分割;然后利用面片法线的方向和模长进行面片过滤,获得包含桥面的候选面片;最后对候选面片进行邻接区域平面元融合,使用统计分布方法筛选融合区域,获得桥面点云。实验证明,该方法可以有效分割桥梁点云的桥面,稳定性较高且能保留体素化前的原始数据。相较于区域生长法和超体素区域生长法,该方法在跨区域融合方面有较好的抑制作用,更适用于桥梁点云的桥面分割。  相似文献   

准噶尔盆地车排子凸起东缘下切谷特征及其形成机制     

秦磊  李小刚  邱子瑶  李志军  徐少华  李仪汶  陈岑  汪佳蓓  文思奇 《现代地质》2021,35(3):832-840

下切谷是层序地层学研究的重要内容之一,同时也是寻找地层、岩性等圈闭的有利地区。综合利用钻测井、三维地震资料以及地震平面属性信息,在车排子凸起至红—车断裂带区域识别出下切谷沉积体系,对下切谷的发育特征以及形成机制进行分析,结果表明:地震振幅绝对值之和属性体显示研究区发育4条近东西流向的下切谷,主要表现为分支型和单一型的平面形态特征。在地震剖面上,几何形态以V形和U形为主,谷内沉积物充填样式有双向上超充填型和侧向加积充填型,同时具有加积、前积和上超等地震反射特征,属于“顺源堆积”与“溯源堆积”的交互沉积。结合准噶尔盆地车排子凸起中生代构造及气候演化特征分析认为,凸起东缘下切谷形成于晚侏罗世。该时期车排子凸起强烈隆升,相对湖平面急剧下降,河流侵蚀下伏地层导致下切谷形成。下切谷内沉积充填阶段发生在白垩纪。该时期车排子凸起剧烈下沉,相对湖平面上升,下切谷持续性的接受沉积充填。  相似文献   

Study on Retrieving Key Ecological Parameters in Mountainous Regions by Remote Sensing Methods and Evaluating Their Spatio-temporal Representativeness     

Ainong Li  Jinhu Bian  Gaofei Yin  Huaan Jin  Wei Zhao  Zhengjian Zhang  Xi Nan  Guangbin Lei 《地球科学进展》2018,33(2):141-151

Focusing on the Key Project of National Natural Science Foundation of China “A study on retrieving key ecological parameters in mountainous regions by remote sensing methods and evaluating their spatio-temporal representativeness”, this paper introduced the project background, objectives, research status, the key scientific questions, main contents of the research, the overall methodology and the deliverables. Choosing different topographic gradient and vegetation background, this project will conduct researches on retrieving key ecological parameters such as LAI and NPP in mountainous areas, evaluating their spatio-temporal representativeness, analyzing the influence of complex terrain on remote sensing signals and the remote sensing products, and finally trying to make a breakthrough in the theory and methodology of ecological parameters retrieving in mountains area.  相似文献   

应用扫描电镜-X射线能谱研究神东矿区砂岩中结构面的微观结构及元素特征     

李回贵  李化敏  李长兴  陈善乐 《岩矿测试》2018,37(1):70-78

神东矿区砂岩地层中存在大量的结构面,这种结构面的存在会对岩层的力学性能、超声波传播、破坏形式以及力的传递等都有显著的影响,但是结构面的微观结构及元素特征是其主要原因之一。本文以布尔台煤矿、大柳塔煤矿和补连塔煤矿地层砂岩中的结构面为研究对象,采用FEI-SEM扫描电镜和能谱仪对不同类型结构面的微观结构和元素特征进行了研究。结果表明:神东矿区砂岩中的结构面可以分为两大类(Ⅰ_和Ⅱ),其中Ⅰ_类又可以分为三个亚类(Ⅰ_1、Ⅰ_2、Ⅰ_3);Ⅰ_类主要含有煤,Ⅱ类主要含有白云母。Ⅰ_1和Ⅱ类结构面颗粒感不明显,颗粒边界不清晰,Ⅰ_2和Ⅰ_3类结构面颗粒感比较明显,颗粒边界比较清晰。Ⅰ_1、Ⅰ_2、Ⅰ_3和Ⅱ类型结构面的孔隙直径和裂隙长度(#m)分别为2.1、81.8、8.9、38.8、4.5、143.7和3.8、13.8。Ⅰ_1类结构面主要组成元素是C、O、Si、Al、K、Ti和Fe;Ⅰ_2类结构面主要为C;Ⅰ_3类结构面主要为C、O、Si、Al、K和Mg;Ⅱ类结构面的主要元素有C、O、Si、Al、K和Ti。神东矿区地层中结构面主要元素为C和O,两种类型的微观结构存在差异。研究结果有助于进一步揭示神东矿区顶板动力灾害及台阶下沉等现象。  相似文献   

房山区贾金路边坡稳定性评价与治理方法研究   总被引：2，自引：2，他引：0       下载免费PDF全文

张硕 《探矿工程》2018,45(10):97-103

公路是国家经济发展的主要载体,公路沿线的边坡稳定性评价及治理工作会成为今后很长一段时间的重点工作。本文以北京市房山区G108国道K3+500～K4+720路段6处危岩治理为工程背景,开展岩质边坡稳定性评价方法及治理措施研究。本文研究的重点是山体边坡是否稳定,同时选取最为有效的治理方案,为类似治理项目提供借鉴。  相似文献   

Random field characterization of uniaxial compressive strength and elastic modulus for intact rocks     

《地学前缘(英文版)》2018,9(6):1609-1618

Rock properties exhibit spatial variabilities due to complex geological processes such as sedimentation,metamorphism, weathering, and tectogenesis. Although recognized as an important factor controlling the safety of geotechnical structures in rock engineering, the spatial variability of rock properties is rarely quantified. Hence, this study characterizes the autocorrelation structures and scales of fluctuation of two important parameters of intact rocks, i.e. uniaxial compressive strength(UCS) and elastic modulus(EM).UCS and EM data for sedimentary and igneous rocks are collected. The autocorrelation structures are selected using a Bayesian model class selection approach and the scales of fluctuation for these two parameters are estimated using a Bayesian updating method. The results show that the autocorrelation structures for UCS and EM could be best described by a single exponential autocorrelation function. The scales of fluctuation for UCS and EM respectively range from 0.3 m to 8.0 m and from 0.3 m to 8.4 m.These results serve as guidelines for selecting proper autocorrelation functions and autocorrelation distances for rock properties in reliability analyses and could also be used as prior information for quantifying the spatial variability of rock properties in a Bayesian framework.  相似文献   

Space,scale, and regional inequality in provincial China: A spatial filtering approach     

《Applied geography (Sevenoaks, England)》2015

This paper investigates regional inequality and development in China's Guangdong province by employing the multi-scale and multi-mechanism framework. The study further examines the relationship between space, scale, and regional inequality by applying a spatial filtering method that eliminates spatial dependence of the data and quantifies the extent to which spatial effects have contributed to regional inequality at multiple scales. The results suggest that over 90% of the divide between the core of the Pearl River Delta (PRD) and the periphery areas of Guangdong province can be explained by the effect of strengthening spatial dependence. By incorporating spatial filters in space-time models, we also reveal the space-time and core-periphery heterogeneities of development mechanisms. Our study confirms that the integration of a multi-scale and multi-mechanism framework and rigorous spatial analysis methods, such as spatial filtering and space-time modeling, helps better understand the complexity of regional development in China.  相似文献   

Comparative spatial inequality dynamics: The case of Mexico and the United States     

《Applied geography (Sevenoaks, England)》2015

In this paper we examine the trajectory of regional income inequality dynamics for two neighboring national systems. Using data on 3038 US counties and 2418 Mexico municipios, from 2000, 2005, and 2010, we employ recent extensions of spatial Markov chains and space-time mobility measures, to consider the following questions: Are regional inequality dynamics fundamentally distinct between Mexico and the United States? Does the role of spatial context influence the distributional dynamics of the two systems? Finally we examine if there is a distinct international border region that displays inequality dynamics different from those of the internal regions of the two national systems. Strong evidence of spatial heterogeneity in regional income mobility is found between the two national systems, with Mexico having higher mobility relative to the US. The international border region is found to have distinct mobility dynamics from either national system, experiencing the strongest mobility. Extensive evidence of spatial contextual effects are found throughout the US-Mexican pooled data set indicating that a region's transitional dynamics are influenced by incomes of neighboring regions.  相似文献