GPS应用于建筑物变形观测的探讨与展望

随着全球定位技术的不断发展,GPS在工程建设领域的应用也越来越广泛。主要介绍GPS在三维定位方面的优点,并讨论其代替精密水准测量(沉降观测)及传统的水平位移监测的可能性。     

大冶铁矿国家矿山公园规划实践

大冶铁矿的开发利用在为我国的钢铁事业作出巨大贡献的同时,也给矿区的地表环境、森林资源带来了很大的破坏。矿山公园的规划实施可极大地改善矿山环境,为矿山的可持续发展提供较好的途径。     

数字摄影测量相机在航空摄影测量及大比例尺数字化成图中的应用

分析了数字摄影测量相机(DMC)在航空摄影测量及大比例尺数字化成图中遇到的问题,如摄影比例尺的选择;数字解析空中三角测量野外像控点间航向基线数、旁向航线数、区域网总航线数的确定;摄影测量平台软件的选择;对计算机硬件的要求;摄影精度、加密精度、成图精度等.     

碳酸盐型磷矿的反浮选工艺研究

针对某碳酸盐型磷矿,采用反浮选工艺流程进行试验研究,获得了低镁优质磷精矿。反浮选工艺具有药剂种类少,分选效率高,选矿技术指标先进,操作控制容易等优点,是选别碳酸盐型磷矿的先进浮选工艺。     

Multiple Volcanic Episodes of Flood Basalts Caused by Underplating

Most Large igneous provinces (LIPs) are emplaced within <10 Ma, with a main pulse of the magmatism in<1 Ma[1]. For example, the Siberian Traps [2] and the Deccan Traps [3] were probably erupted within one million years. Many events, such as the Columbia River event, feature a single pulse of magmatism, followed by a protrac-ted period of magmatism at a much lower rate that is linked to a plume tail[4].     

对一种振冲碎石桩复合地基沉降计算方法——Priebe法的改进

通过对经典的Priebe沉降计算法分析,以及面积置换率的变化对桩体压缩性假设作了改进;对桩土重度差异及承受荷载时应力和变形与深度的关系作了分析,归纳出相应的数学计算公式,用工程实例进行了验证。得到的结果表明改进是合理、适用的,可为今后的设计和施工提供参考。     

附非负约束平差模型的最小二乘估计

研究了不等式约束下的平差问题,即先将不等式约束的最小二乘问题转换成凸二次规划问题,然后求其最优解.给出了几个判定最优解的充分必要条件,以及非负约束下的平差问题参数最小二乘估计的一般形式,并给出了简明的算法.模拟实例说明,此算法可以很好地应用于实际测量中的平差计算.     

GIS在四川城市环境地质调查评价中的应用

将GIS应用于四川城市环境地质调查评价,建立一套完整的标准,指导全省21城市的数据库建设工作。在数据库的基础上利用MAPGIS二次开发平台,集成四川城市环境地质问题调查评价信息系统,供地方政府和各级管理机构使用。     

Changes in hydrogeological properties of the River Choushui alluvial fan aquifer due to the 1999 Chi-Chi earthquake, Taiwan

Changes in hydrogeological properties of the River Choushui alluvial fan aquifer before and after the 1999 Chi-Chi earthquake, Taiwan, have been identified using pumping tests. Three wells, SH2, YL2 and SC2, located in a compressional zone with high coseismic groundwater levels, were tested. The threshold of the aquifer deformation with respect to transmissivity (T) is greater than that with respect to storage coefficient (S). Decreases in the post-earthquake S are approximately 60% at SH2 and SC2, indicating aquifer compression after the Chi-Chi earthquake. Changes in the post-earthquake T range from 61% increase to 0.8% decrease. Moreover, results from anisotropy analysis of T at SC2 further illustrate that normal stresses induced by the Chi-Chi earthquake have consolidated soil particles. Soil particles dilated laterally after the earthquake, resulting in an increase of the equivalent T. The changes in hydrogeological properties have a considerable influence on spatiotemporal fluid pressure and horizontal groundwater movement, resulting in different amounts of drawdown during post-earthquake pumping.     

Response of riparian vegetation to water-table changes in the lower reaches of Tarim River, Xinjiang Uygur, China

The lower reaches of Tarim River in the Xinjiang Uygur region of western China had been dried out for more than 30 years before water began to be diverted from Konqi (Peacock) River via a 927-km-long channel in year 2000, aimed at improving the riparian ecological systems. Since then, eight intermittent water deliveries have been carried out. To evaluate the response of riparian vegetation to these operations, the groundwater regime and vegetation changes have been monitored along the 350-km-long stem of the river using a network of 40 dug wells at nine transects across the river and 30 vegetation plots at key sites. Results show that the water table rose remarkably, i.e. from a depth of 9.87 m before the water delivery to 3.16 m after the third water delivery. The lateral distance of affected water table extended to 1,050 m from the riverbank after the fourth water delivery. The riparian vegetation has changed in composition, type, distribution, and growing behavior. This shows that the water deliveries have had significant effects on restoration of riparian ecosystems.