北京市地面沉降监测系统及技术方法

北京市地面沉降监测系统由地面沉降监测网、地面沉降专门监测网、GPS监测网、地下水位动态监测网及InSAR监测网构成.结合北京市近年来地面沉降监测工作,分析总结了标孔监测和质量控制方法,提出了将GPS监测分为控制网和监测网两级监测的方法,提高了监测精度,尝试采用InSAR测方法对部分重要轨道交通进行地面沉降专项监测研究.对地面沉降监测网络建设及优化有一定的指导意义.     

利用差分GPS进行地面沉降监测的研究

为了更好地利用GPS对地面沉降进行监测,详细介绍了差分GPS静态相对定位的工作原理,探讨了差分GPS测量应用于地面沉降监测时的实现方法,介绍了影响差分GPS定位精度的因素。结果表明,利用差分GPS静态测量大范围地面沉降的方法精度高,工作效率高。     

天津市高精度GPS地面沉降监测网数据处理中的若干技术问题探讨

本文以天津市区地面沉降GPS监测网为例,探讨了高精度GPS地面沉降监测网数据处理中的若干技术问题。研究表明,GPS数据处理软件、GPS监测网的框架基准、大气延迟改正和粗差对计算结果的精度有很大影响。在对GPS原始观测数据进行后处理时,只有对影响计算精度的各种误差源进行有效改正,GPS高程分量的精度才有可能达到毫米级,才能满足地面沉降监测的要求。     

大范围地面沉降的差分GPS监测法

详细介绍了差分GPS静态测量和动态测量两种测量模式应用于大范围地面沉降监测的工作原理,探讨了GPS测量与水准测量,这两种方法因测量基准面不同,而使得所测地面沉降量存在的差异。将差分GPS静态测量模式实际应用于天津市的地面沉降监测,通过对其4年的实际测量精度的分析表明,对于大范围地面沉降监测,采用差分GPS静态测量法取代长距离的一等精密水准测量是完全可行的。     

唐山基岩标全部竣工

唐山市基岩标工程系于“河北平原地面沉降调查与监测”工作项目的一部分。所属计划项目为华北平原地面沉降调查与监测。其目的是通过基岩标、分层标、GPS基准站、GPS观测墩等建设．实现平原区地面沉降的有效监测，并逐步建成全国地质灾害预警系统，达到防灾减灾．保证国民经济可持续发展。     

GPS在西安市地面沉降与地裂缝监测中的应用研究

本文从GPS监测网的布网原则和设计方案出发,对GPS外业观测和内业数据处理中的关键技术进行了深入研究,提出了一套适用于大城市地面沉降与地裂缝灾害监测的作业方法和数据处理方案。通过西安地区地面沉降和地裂缝的GPS监测实践,证明了本文提出的监测网的布设原则、GPS外业施测和内业数据处理方案是切实可行的,并且通过GPS监测获取了西安地面沉降和地裂缝近期活动的有关数据信息,且其与精密水准结果具有很好的一致性。     

苏锡常地区地面沉降监测网络体系建设初探

本文从苏锡常地区地质环境基本特征出发,在分析了该地区地下水开采及地面沉降现状和特点基础上,提出建设苏锡常地区地面沉降监测网络体系的初步构想.该监测网络的建立,将为今后开展地面沉降GPS监测及相应的专题研究工作奠定基础.     

地表可恢复性沉降阈值的监测与分析

针对地面沉降问题的不同认识与见解,采用精密水准监测技术、GPS技术,在系统分析几十年原位监测数据的基础上,提出了地面沉降具有一定自恢复能力的观点,总结出了地面沉降可恢复性沉降阈值的范围,叙述了地面沉降原位监测的合理方法及监测要领.     

高速铁路区域地面沉降监测体系构建

区域地面沉降会对在建和运营中的高速铁路产生影响,掌握高速铁路沿线地面沉降状况是防治和减缓其影响的基础工作。阐述了建立高速铁路区域地面沉降监测体系的原则与方法,并以京津城际高铁为实例,基于系统调查基础上的地面沉降危险性分区评价成果,提出了构建包括地下水动态监测、GPS、InSAR、水准测量、分层标测量的监测体系框架及其重点内容与关键环节。     

北京市地面沉降防治工作探讨

北京市地面沉降监测工作在新世纪发展较快,目前已经形成了由基岩标—分层标监测、精密水准测量、GPS测量、InSAR监测和区域地下水动态监测一体的监测系统,在地面沉降灾害监测、机理研究、灾害防治等方面均取得长足发展。本文从基础研究、地下水控采、法治建设、区域联动和多部门配合、线路工程地面沉降防控等多个方面对北京市地面沉降的防治工作进行了探讨,指出:多个途径控制地下水超采问题,是从源头上防治地面沉降的根本方法;法治建设是地面沉降防治工作的制度保障;区域联动和多部门配合是地面沉降防治工作的必然趋势;高速铁路等线路工程是地面沉降防治工作的重点和突破口。     

Monitoring ground subsidence induced by salt mining in the city of Tuzla (Bosnia and Herzegovina)

Salt mining induced ground subsidence is a major hazard in the city of Tuzla (Northeastern sector of Bosnia and Herzegovina) and its surroundings since 1950, when solution mining of salt deposits by boreholes began. An analysis of the large (and never before processed) amount of topographical data collected during two periods: from 1956 to the Balkan War, and from 1992 to 2003 has been made. The analysis reveals a cumulative subsidence as high as 12 m during the whole period, causing damage to buildings and infrastructures within an area that includes a large portion of the historical town. Human-induced subsidence, (with rates up to 40 cm/year in the most developed area), has been investigated to recognize the areas affected by the sinking phenomenon and to produce a subsidence hazard. The time series of topographical observations have been enlarged by conducting new surveys in the urban area by modern space-geodesy methodologies, such as static relative GPS (Global Positioning System) and high resolution satellite imageries. The GPS monitoring started in 2004 and detected a decrease in the subsidence rates to 20 cm/year related to the reduction of salt exploitation. There is close correlation between the average subsidence rate and the annual amount of salt extracted.     

On causes and impacts of land subsidence in Bandung Basin, Indonesia

The Bandung Basin is a large intra-montane basin surrounded by volcanic highlands, in western Java, Indonesia, inhabited by more than seven million people. The basin, an area of about 2,300 km², is a highland plateau at approximately 650–700 m above sea level and is surrounded by up to 2,400 m high Late Tertiary and Quaternary volcanic terrain. Based on the results of nine GPS surveys conducted since 2000 up to 2011, it was shown that several locations in the Bandung Basin have experienced land subsidence, with an average rate of about ?8 cm/year and can go up to about ?23 cm/year in certain locations. A hypothesis has been proposed by several studies that land subsidence observed in several locations in the Bandung Basin has been caused mainly by excessive groundwater extraction. It is found that there is a strong correlation between the rates of groundwater level lowering with the GPS-derived rates of land subsidence in several locations in Bandung Basin. The GPS results in this study detected significant subsidence in the textile industry area, where very large volumes of groundwater are usually extracted. The impact of land subsidence in Bandung can be seen in several forms, mainly in the cracking and damage of houses, buildings and infrastructure. Land subsidence also aggravates the flooding in Bandung Basin, which has brought huge economic losses and deteriorated the quality of life and environment in the affected areas.     

基于时序InSAR和GPS技术的北京平原区地表三维形变场特征

文中采用InSAR与GPS技术相结合,获取了北京平原区时序地表三维形变场信息,分析了其分布特征与演化规律.研究表明:(1)北京平原区在抽水引发的第四系附加应力场作用下,地表呈现出显著的三维变形特征,以垂向变形为主,并辅以水平向位移.(2)平原区地面沉降主要集中在东部、北部和南部等地,存在多个沉降中心,总体呈减缓的趋势....     

GPS测量技术在锡山市地面沉降研究中的应用

通常研究认为, 苏锡常地区超量开采地下水是产生地面沉降最主要的因素之一。锡山市地下水开采十分强烈, 其地面沉降灾害也最为严重。为了有效地分析研究地面沉降的发生发展过程, 必须获取一定时间间隔内的地面沉降实测值, 全球定位系统 (GPS)就是一种既经济又高效的测量手段。本文在简要介绍了锡山市地质、水文地质及地下水开发利用情况的基础上, 重点阐述了运用GPS测量技术对锡山市地面沉降进行首次实测的情况, 并对其测量结果进行了系统分析, 最后对锡山市地面沉降的发展历史和现状进行了初步讨论。     

GPS/terrestrial 3D laser scanner combined monitoring technology for coal mining subsidence: a case study of a coal mining area in Hebei, China

In order to overcome the shortage that point-based data acquisition techniques cannot retrieve the whole basin subsidence caused by underground mining, and to avoid complex splicing of terrestrial 3D laser scanner (TLS) point cloud data and the errors caused by such splicing, GPS/TLS combined technology is employed for mining subsidence monitoring. The basic idea of the monitoring technology is put forward. In this article, an application of the method to a coal mining area in China is presented. Support vector machine (SVM) model for GPS level conversion in the mining area is established, and a comparative analysis of SVM, BP neural network and polynomial established local quasi-geoid in the mining area is conducted. Ground surface digital elevation model (DEM) of the mining area is established by using TLS point cloud data, and the ground surface dynamic subsidence basin is obtained through a subtraction of two DEMs. The results indicate that the quasi-geoid established by using SVM model features a relatively high level of stability and accuracy and that the established mining surface DEM and subsidence basin can provide the fundamental data for the reconstruction of ecological environment in the mining area. GPS/TLS combined monitoring technology is a new monitoring technology, which entangles the advantages of both GPS and TLS and could offset their disadvantages, thus obtaining complementary advantages. According to analysis on its application in the mining area, we conclude that the technology is feasible and has a great application prospect for the mining area purposes.     

Assessment of ground subsidence hazard near an abandoned underground coal mine using GIS

This study constructs a hazard map for ground subsidence around abandoned underground coal mines (AUCMs) at Samcheok City in Korea using a probability (frequency ratio) model, a statistical (logistic regression) model, and a Geographic Information System (GIS). To evaluate the factors related to ground subsidence, an image database was constructed from a topographical map, geological map, mining tunnel map, Global Positioning System (GPS) data, land use map, lineaments, digital elevation model (DEM) data, and borehole data. An attribute database was also constructed from field investigations and reports on the existing ground subsidence areas at the study site. Nine major factors causing ground subsidence were extracted from the probability analysis of the existing ground subsidence area: (1) depth of drift; (2) DEM and slope gradient; (3) groundwater level, permeability, and rock mass rating (RMR); (4) lineaments and geology; and (5) land use. The frequency ratio and logistic regression models were applied to determine each factor’s rating, and the ratings were overlain for ground subsidence hazard mapping. The ground subsidence hazard map was then verified and compared with existing subsidence areas. The verification results showed that the logistic regression model (accuracy of 95.01%) is better in prediction than the frequency ratio model (accuracy of 93.29%). The verification results showed sufficient agreement between the hazard map and the existing data on ground subsidence area. Analysis of ground subsidence with the frequency ratio and logistic regression models suggests that quantitative analysis of ground subsidence near AUCMs is possible.