西安地铁隧道穿越饱和软黄土地段的地表沉降监测

以西安地铁一号线朝阳门站—康复路站区段饱和软黄土地铁隧道为研究对象,通过施工期现场地表沉降变形监测,分析了在饱和软黄土特殊地层条件下隧道浅埋暗挖法施工引起的该区段地表沉降变形规律以及地表沉降槽分布特征。结果表明:在饱和软黄土隧道开挖时,随着掌子面的推进,隧道顶地表沉降可分为沉降微小阶段、沉降显著发展阶段、沉降缓慢阶段和沉降稳定阶段;单线隧道开挖后的最大地表沉降量为18.89mm,双线隧道开挖后的最大地表沉降量为36.4mm;已开挖隧道对围岩土体的扰动作用使得后开挖隧道的地表沉降发展较大;双线隧道的地表沉降槽宽度接近单线隧道沉降槽宽度的2倍,因此可以将其近似为单线隧道地表沉降槽宽度与双线隧道轴线中点距离之和;单线隧道开挖后地表沉降槽宽度为8.4～9.3m,双线隧道开挖后地表沉降槽宽度为16.2～17.5m;隧道开挖施工的沉降槽宽度参数为0.435～0.467,单线隧道开挖后的地层损失率为0.765%～1.324%,双线隧道开挖后的地层损失率为1.231%～2.200%。     

Comprehensive tests on rising height of capillary water for coarse grained soil

According to the comprehensive tests on the rising height of capillary water for seven kinds of different coarse grained soil by use of the method of standpipe,the relationship between the rising height of capillary water and time was obtained,and the influencing factors and rules were analyzed.The data of the steady rising height of capillary water were obtained,and the regression equation of coarse grained soil on steady height and physical indexes(effective grain d 10 and porosity n) was found.Compared with Hazen’s and other expressions that could estimate the steady height of capillary water of coarse grained soil,the proposed method is satisfactory and the defects of the latter were pointed out.     

澳门地理数据的整合进程——以街道门牌数据为例

澳门自2003年引入外资以来,在过去十年间经历迅速且巨大的改变,由原来一个夕夕无名的小渔村,转眼间变为国际知名的旅游城市。面对急速的社会发展,澳门特区政府面临各项大小不一的空间决策,在进行决策的背后,实在需要强大的、科学化的空间分析工具加以辅助。然而,受限于历史的原因,多数政府部门并未有完善的地理空间数据库,也未能让地理数据互相整合,以致在规划及发展过程中面对诸多的制约。本文以地图绘制暨地籍局过去两年不断整合的街道门牌数据及建构澳门街道门牌查询系统的经验,阐述澳门地理空间科技及数据整合的发展近况,并藉邻近地区的经验从多角度、多面向提供整合澳门地理数据的发展方向,以解决多年来未能整合的窘况,并为未来筹建地理资料共享平台作准备。     

2011年3月云南一次寒潮天气过程分析

2011年3月15日～18日是一次典型的南支槽与强冷空气相结合的天气过程,此次过程对云南省造成了强降温雨雪天气.为了研究此次天气过程的成因以及为今后类似天气过程提供预报思路,利用6h间隔的NECP1°×1°再分析资料、常规观测资料和TBB黑体亮温资料,对此次天气过程进行天气学分析和诊断分析.分析结果表明:500hPa高度上中高纬度呈横槽型,横槽与高原东侧的低槽连接,槽后强劲的西北气流为这次寒潮天气过程带来强冷平流;南支槽的东移并加强使暖湿气流不断向云南境内输送;高低层冷暖气流交汇,低层切变线、地面冷锋的持续作用触发了此次降温雨雪天气.     

Geochronology and geochemistry of Baicaogou tuff in Yanji,NE China and its tectonic implications for Early Cretaceous

The authors studied zircon U-Pb age and geochemical data of Baicaogou tuff in Yanji,Jilin Province.The results indicate that the rocks formed in Early Cretaceous( 125. 6 ± 2. 3 Ma). Geochemically,these tuffs have high Si O2 and total Na2 O + K2 O,low Mg O and Fe O,and they belong to metaluminous series,the rock are enriched in LREEs and LILEs,depleted in HREEs and HFSEs such as Nb,Ta,Ti,and P,exhibiting an affinity to I-type granite. All these characteristics implied that the volcanic rocks were derived from partial melting of lower crust. Combined with the geochronology and geochemical features of the coeval igneous rocks within NE China,it is concluded that Yanji area was in a back-arc extensional setting in response to the subduction of the Paleo-Pacific Plate beneath the Eurasian Plate.     

BIM与SuperMap GIS数据集成技术

现代社会大型复杂建设工程越来越多,室内3D GIS应用需求旺盛,但海量室内3D数据的缺乏成为室内GIS应用瓶颈。建筑信息模型(Building Information Models,BIM)提供丰富的建筑空间几何和语义信息,可为GIS所用。BIM与GIS数据集成技术成为国内外研究热点。本文从GIS应用的角度出发,通过分析BIM与GIS在数据标准和几何、语义表达方面的差异,提出BIM与SuperMap GIS 8C软件的数据集成技术,并实现了BIM在SuperMap GIS中的高性能空间分析与可视化。本文的研究有助于扩展SuperMap GIS的应用领域至室内空间,实现室外到室内、城市宏观到建筑微观的一体化应用,满足大型复杂室内场所的应急救援、导航与位置服务需求,服务于智慧城市建设。     

Organic carbon deposition flux on the North Chukchi Sea shelf based on 210pb radioactivity dating

Deposition of organic carbon forms the final net effect of the ocean carbon sink at a certain time scale. Organic carbon deposition on the Arctic shelves plays a particularly important role in the global carbon cycle because of the broad shelf area and rich nutrient concentration. To determine the organic carbon deposition flux at the northern margin of the Chukchi Sea shelf, the 210pb dating method was used to analyze the age and deposition rate of sediment samples from station R17 of the third Chinese National Arctic Research Expedition. The results showed that the deposition rate was 0.6 mm＇aI, the apparent deposition mass flux was 0.72 kg.m2a1, and the organic carbon deposition flux was 517 mmol C.m2.al. It was estimated that at least 16% of the export organic carbon flux out of the euphoric zone was transferred and chronically buried into the sediment, a value which was much higher than the average ratio （-10%） for low- to mid-latitude regions, indicating a highly effective carbon sink at the northern mar- gin of the Chukchi Sea shelf. With the decrease of sea ice coverage caused by warming in the Arctic Ocean, it could be inferred that the Arctic shelves will play an increasingly important role in the global carbon cycle.     

利用实时路况数据聚类方法检测城市交通拥堵点

 城市交通拥堵严重制约其网络总体效率。开展检测交通拥堵点可有效识别网络瓶颈,以整治交通拥堵现象。对此,本文提出一种新的城市交通时空拥堵点检测的方法:即采用实时路况数据,通过定义时空关联,检测时空意义上长期性、规律性交通拥堵点。本文基于DBSCAN(Density-Based Spatial Clustering of Applications with Noise)算法,以成都市为试验区,实现了这种拥堵点检测方法。试验表明,该方法可快速、有效、准确地检测出城市道路严重拥堵路段,并确定其拥堵时空范围,为交通管理、交通拥堵机理分析、交通拥堵预测等提供参考。     

基于Voronoi邻近的物流车辆路径快速优化算法

 现代物流业需要快速高效并智能化制定物流运输方案。传统路径优化方法适合处理中小规模的车辆路径问题,计算时间较长,方案质量较低,故需发展短时间内能提供高质量路径方案的启发式算法。针对大规模物流车辆路径优化,本文提出了一种Voronoi邻近的快速优化方法。该方法先创建初始解,而后进行迭代优化。初始解创建利用Voronoi邻近关系,顾及车辆容量约束,自底向上进行客户点空间聚类,将问题降维;采用最廉价插入算法安排聚类内部路径,生成性质良好的初始解。迭代优化在客户点Voronoi邻近内进行有效的局部搜索,利用模拟退火机制接受较差解,从而跳出局部最优,不断提高解的质量。本文利用模拟生成的北京市大规模车辆路径问题进行实验,结果表明:本文算法能够在4500s内优化客户点高达12 000个物流车辆路径问题,计算时间较短,解的质量优良,算法性能稳定。本文与其他算法比较,能在较短时间内提供高质量车辆路径方案,适用于大规模物流车辆路径的优化。