Predicted ultimate capacity of laterally loaded piles in clay using support vector machine

The determination of ultimate capacity of laterally loaded pile in clay is a key parameter for designing the laterally loaded pile. The available methods for determination of ultimate resistance of pile in clay are not reliable. This study investigates the potential of a support vector machine (SVM)-based approach to predict the ultimate capacity of laterally loaded pile in clay. The SVM, which is firmly based on statistical learning theory, uses a regression technique by introducing an ?-insensitive loss function. A sensitivity analysis has been carried out to determine the relative importance of the factors affecting ultimate capacity. The results show that SVM has the potential to be a practical tool for prediction of the ultimate capacity of pile in clay.     

鞍山垃圾与渣土受纳场边坡锚索支护治理设计与施工

介绍了鞍山市千山区建筑垃圾与渣土受纳场边坡锚索支护治理工程锚索的设计与计算,以及施工工艺及监测等情况。     

基坑开挖与支护FLAC数值模拟计算及分析

介绍了FLAC-2D,根据基坑工程具体实例,采用FLAC-2D对基坑开挖及其支护结构状态进行计算和分析;并模拟了在未进行支护条件下的基坑开挖,得出了基坑土体在支护和未支护条件下,土体的应力状态、位移等值线图、位移矢量图、最终沉降量和结构受力.计算结果也证明了支护结构设计的合理性,对工程设计及施工分别起到了验证和预测的作用.     

Using a groundwater quality negotiation support system to change land-use management near a drinking-water abstraction in the Netherlands

A negotiation support system (NSS) was developed to solve groundwater conflicts that arose during land-use management. It was set up in cooperation with the stakeholders involved to provide information on the impact of land use, e.g., agriculture, nature (forested areas), recreation, and urban areas, on the quality of both infiltrating and abstracted groundwater. This NSS combined simulation programs that calculate (1) the concentrations of nitrate in shallow groundwater for each land-use area and (2) the transport of nitrate in the groundwater-saturated zone. The user interface of the NSS enabled scenario analyses. The NSS was validated at a drinking-water abstraction near Holten (the Netherlands) using a spatial planning process aimed at sustainable land-use and groundwater-resource management. Two land-use scenarios were considered: a base scenario reflecting the autonomous development and an adapted land-use scenario. The calculated results for shallow groundwater provided an explicit spatial overview of the impact of historical land use and N application on the quality of abstracted groundwater as well as insight into the impact of changes in land use and N application. Visualization of the conflicting interests of agriculture and the drinking-water abstraction helped all stakeholders accept the necessary changes in land use identified by the adapted land-use scenario of the NSS. These changes were included in the preferred land-use management option in the regional planning process, which has since been formalized. The NSS provided system insight, scoping analyses, and education, in addition to generating quantitative information on the impact of land-use functions on groundwater quality.     

公共财政应急支持体系构建——以云南大姚地震为例

通过对2003年云南大姚地震中财政应急支持过程的回顾,分析了财政应对地震类突发事件中存在的一系列问题,并结合当前财政应急支持的现状,参照日本灾害救助的经验,提出了完善我国财政应急支持体系的对策建议.     

超大断面低扁平率公路隧洞先成预应力结构新型支护体系数值模拟

为适应日益增长的经济和交通发展需求,修建以4车道公路隧道为代表的超大断面低扁平率公路隧洞的需求初露端倪,这类隧道的低扁平率特征使传统的隧道支护体系面临许多困难,急待开发新型的隧洞支护体系。采用FLAC数值模拟平台研究了基于隧洞“先成结构法”支护理念的“先成预应力结构”新型支护体系在提高超大断面低扁平率公路隧洞洞室稳定性方面的效果,为“先成结构法”支护理念在超大断面低扁平率公路隧洞中的应用实施提供了有力的支持。     

基于智能反分析的水布垭电站地下厂房机窝施工方案优化

采用正交设计、三维数值模拟、遗传算法与支持向量机,建立了清江水布垭电站地下厂房的智能反分析流程。按照上述流程,利用前6层开挖的现场监测信息对有关岩层的力学参数进行反分析,根据反分析的参数对后续的机窝施工进行数值模拟计算和方案优化。推荐的机窝施工方案采用槽挖方式,同时应用锚桩、软岩置换、锚喷支护等措施,兼顾了高边墙和机窝岩台的稳定性。优化结果对厂房施工具有重要的指导作用。     

基于不同窗口纹理特征的SVM土壤盐渍化信息提取方法与精度分析研究

以塔里木盆地北缘绿洲--渭干河-库车河三角洲绿洲为例,借助ENVI遥感软件,利用ETM+数据,探讨了该绿洲土壤盐渍化信息提取的方法.传统的遥感图像分类方法多数在解决问题上存在精度不高、分类效率较低、不确定性强的缺陷,所以,选择好的分类方法对于提取盐渍化信息是至关重要的.近年来,将SVM应用于遥感图像分类已成为新的发展趋势.文章提出了基于纹理特征的支持向量机(Support Vector Machine,SVM)的分类方法,得出以下结论:分别结合3×3,5×5,7×7,9×9,11×11,13×13窗口纹理特征和光谱的SVM分类精度都很高,达到93%以上.并且在验证分类精度时,发现结合光谱和9×9窗口纹理信息的SVM分类的结果更符合实际情况.所以说加入纹理特征后使得光谱信息比较接近的3类地物(重度、中度、轻度盐渍地)的区分性增大,从而使精度提高.因此,基于纹理特征的SVM分类方法更有利于遥感图像分类和盐渍化信息监测,是地物遥感信息提取的有效途径.     

对推进地震预测、预报工作的一些政策问题的讨论

推进地震预测、预报不能只是地震局工作的改进,国家对待地震预测、预报的工作必须有一个政策的调整。当前地震预测预报工作基本上沿用气象工作的模式,但地震预报和气象预报的水平完全不在一个水平上。地震预测预报工作要把科学研究放到首位,在地震工作的管理体制、财政体制方面都应有一个大的调整。     

Application of support vector machine to synthetic earthquake prediction

This paper introduces the method of support vector machine (SVM) into the field of synthetic earthquake pre-diction, which is a non-linear and complex seismogenic system. As an example, we apply this method to predict the largest annual magnitude for the North China area (30°E-42°E, 108°N-125°N) and the capital region (38°E-41.5°E, 114°N-120°N) on the basis of seismicity parameters and observed precursory data. The corresponding prediction rates for the North China area and the capital region are 64.1% and ...