崔家冲隧洞软弱围岩注浆工法的研究应用

长沙引水及水质环境工程崔家冲隧洞要穿越区域性高棱山压扭性断层F86,断层宽度达100余米,长度达1000余米,洞顶以上地表覆盖层达110 m,其规模为同类工程所罕见。由于断层破碎带岩体强度低,透水性好,穿越断层破碎带洞段的施工成为工程建设中的重点和难点。所以隧洞在施工过程中需采用多种方法穿越众多的不良地质段。主要介绍和探讨了该隧洞穿越F86断层破碎带所采用的超前预注浆技术、超前支护技术及长管棚施工技术,为今后在类似工程中提供施工借鉴。     

海河平原北部地区水土地质环境研究中的若干问题

海河平原北部地区属于半干旱自然地理环境且仍在干化,自山前至滨海的山麓堆积-河流沉积-海陆交互沉积序列的平原地貌地质环境,土壤地球化学环境以高Ca、Mg、F,低Se、Mo、I和弱碱性为特征且正在经历酸化过程,潜水环境以淡水-微咸水-弱碱性为特征且有碱化的趋势。人为作用与自然作用一起构成了本区水土地质环境演化的双重驱动力,但在表现形式和区域分布方面驱动强度存在明显的差异性,土壤环境质量良好但潜水环境质量较差且均在恶化。     

海河平原北部地区主要水土环境问题及影响因素

将土壤和潜水作为一个相互作用的系统,提出了研究区土壤酸化及地下水碱化、土地沙化、湿地退化、土地盐渍化等主要水土地质环境问题。系统地研究了海河平原北部地区土壤、潜水等地质环境的影响因素。以土壤剖面实测数据为基础,认为土壤环境主要受自然因素的控制,人类活动的影响也不容忽视;以地下水监测数据为基础,认为潜水环境受自然因素和人类活动双重作用的控制。为研究区水土地质环境保护提供了重要的依据。     

海河平原北部地区山前-滨海表层土壤地质地球化学特征

对海河平原北部地区不同地质地貌类型的表层土壤粒度、矿物成分和元素地球化学进行了研究,结果显示,从山前至滨海表层土壤地质地球化学特征与原生沉积环境的相关关系,在空间上表现出随着地质地貌和沉积环境特征的变化而演变的规律。     

东莞地区土地利用变化预测的CBR和CA方法对比研究(英文)

Many studies on land use change(LUC),using different approaches and models,have yielded good results.Applications of these methods have revealed both advantages and limitations.However,LUC is a complex problem due to influences of many factors,and variations in policy and natural conditions.Hence,the characteristics and regional suitability of different methods require further research,and comparison of typical approaches is re-quired.Since the late 1980s,CA has been used to simulate urban growth,urban sprawl and land use evolution successfully.Nowadays it is very popular in resolving the LUC estimating problem.Case-based reasoning(CBR),as an artificial intelligence technology,has also been employed to study LUC by some researchers since the 2000s.More and more researchers used the CBR method in the study of LUC.The CA approach is a mathematical system con-structed from many typical simple components,which together are capable of simulating complex behavior,while CBR is a problem-oriented analysis method to solve geographic problems,particularly when the driving mechanisms of geographic processes are not yet understood fully.These two methods were completely different in the LUC research.Thus,in this paper,based on the enhanced CBR model,which is proposed in our previous research(Du et al.2009),a comparison between the CBR and CA approaches to assessing LUC is presented.LUC in Dongguan coastal region,China is investigated.Applications of the im-proved CBR and the cellular automata(CA) to the study area,produce results demonstrating a similarity estimation accuracy of 89% from the improved CBR,and 70.7% accuracy from the CA.From the results,we can see that the accuracies of the CA and CBR approaches are both >70%.Although CA method has the distinct advantage in predicting the urban type,CBR method has the obvious tendency in predicting non-urban type.Considering the entire ana-lytical process,the preprocessing workload in CBR is less than that of the CA approach.As such,it could be concluded that the CBR approach is more flexible and practically useful than the CA approach for estimating land use change.     

青藏铁路冻土地区乌丽山垭口段工程地质选线

青藏铁路沿线的多年冻土区分布范围广泛, 冻土不良地质现象发育, 线路通过时难以绕避. 在翔实勘察和认真分析的基础上, 根据多年冻土区铁路选线的原则, 对多年冻土分布的乌丽山垭口区域线路方案进行比选.     

大型崩滑灾害变形三维激光扫描监测技术研究

三维激光扫描技术突破了传统单点测量方法采样点有限、覆盖范围小的不足,实现了对观测对象面的测量。受制于扫描速率和扫测距离的限制,该技术目前在地质灾害领域应用有限,因此也成为热点研究课题。本文针对高陡危岩、大型滑坡等复杂地质环境下地质灾害的三维激光扫描技术,系统探讨了地形构建、DEM建模和几何量测等快速调查方法,并提出了点、线、面相结合的灾害地质体形变监测方法;结合应用案例系统比较和分析了三维激光扫描技术在滑坡、崩塌调查监测中的技术优势和局限性,展望了该项技术在地质灾害领域的应用与发展趋势。     

基于粗糙集理论的地学空间关系规则分析及其应用——以珠江三角洲为例

Spatial relations,reflecting the complex association between geographical phenomena and environments,are very important in the solution of geographical issues. Different spatial relations can be expressed by indicators which are useful for the analysis of geographical issues. Urbanization,an important geographical issue,is considered in this paper. The spatial relationship indicators concerning urbanization are expressed with a decision table. Thereafter,the spatial relationship indicator rules are extracted based on the application of rough set theory. The extraction process of spatial relationship indicator rules is illustrated with data from the urban and rural areas of Shenzhen and Hong Kong,located in the Pearl River Delta. Land use vector data of 1995 and 2000 are used. The extracted spatial relationship indicator rules of 1995 are used to identify the urban and rural areas in Zhongshan,Zhuhai and Macao. The identification accuracy is approximately 96.3%. Similar procedures are used to extract the spatial relationship indicator rules of 2000 for the urban and rural areas in Zhongshan,Zhuhai and Macao. An identification accuracy of about 83.6% is obtained.     

海河平原北部地区土壤地球化学基准值与环境背景值

以北京市、天津市、河北省多目标区域地球化学调查(1:25万)取得的数据为基础,遵循地球化学基准值与环境背景值的概念,根据不同的沉积条件将研究区(即海河平原北部地区)划分为3个统计单元,运用标准化方法,即对土壤表层数据反复剔除异常数据后,通过其他元素与惰性元素Ti的相关关系分别计算得出各指标土壤的基准值;通过对土壤深层数据反复剔除异常数据后,获得了34项指标的平均值、标准离差和变异系数,并以此表征背景值。以上研究为区域土壤环境质量评价与监测预警提供了科学依据。     

土地利用变化预测的案例推理方法

当前,基于案例的推理(Case-Based Reasoning,CBR)在解决复杂的地学问题时.对地学案例的表达和历史案例的相似性计算与推理存在明显缺陷,需要在CBR的表达模型和空间相似性计算与推理算法进行拓展.本文针对土地利用变化问题,首先在分析土地利用变化各种定量方法基础上,提出利用CBR进行土地利用变化分析的研究思路:其次,针对土地利用变化的空间特性及隐含的空间关系特性.给出土地利用变化案例的表达模型,案例间内蕴空间关系抽取算法,以及考虑案例间空间关系的CBR相似性推理模型:最后,进行珠江口区域土地利用变化的CBR方法试验.预测精度达到80%.为了进一步评价CBR方法对土地利用变化预测的有效性.在实例部分采用同样的实验数据进行贝叶斯网络的预测方法实验.由两种方法对比可知.CBR是从复杂到简单进行地学问题求解的一种有效方法.