海上风电单桩式支撑结构冰激振动及参数敏感性分析     

王宾  李红涛  刘嵩  万德成 《海洋工程》2020,38(3):94-101

针对渤海湾某风电场的海上固定式风机支撑结构,采用适用于大直径单桩结构的PSI曲线模拟桩土相互作用,并采用SACS软件建立支撑结构的动力分析模型。首先对支撑结构进行模态分析;其次考虑海冰结构的随机振动作用模式,根据适用于渤海湾的随机冰力谱构造随机冰载荷时程曲线,基于半耦合的时域方法,采用SACS软件对支撑结构进行冰激振动分析,输出塔筒顶部加速度、单桩基底剪力及倾覆力矩等响应参数的时程曲线和响应功率谱;最后针对冰厚、冰速和海冰强度等海冰参数对支撑结构的冰激振动进行敏感性分析。研究结果表明,在随机振动模式下,冰载荷及结构动力响应对冰厚和海冰强度较为敏感,在进行冰激振动分析时应合理确定冰厚和海冰强度等参数。  相似文献   

A probabilistic model for real‐time flood warning based on deterministic flood inundation mapping     

Jiun‐Huei Jang  Pao‐Shan Yu  Sen‐Hai Yeh  Jin‐Cheng Fu  Chen‐Jia Huang 《水文研究》2012,26(7):1079-1089

Deterministic flood inundation mapping is valuable for the investigation of detailed flood depth and extent. However, when these data are used for real‐time flood warning, uncertainty arises while encountering the difficulties of timely response, message interpretation and performance evaluation that makes statistical analysis necessary. By incorporating deterministic flood inundation map outputs statistically by means of logistic regression, this paper presents a probabilistic real‐time flood warning model determining region‐based flood probability directly from rainfall, being efficient in computation, clear in message, and valid in physical meaning. The calibration and validation of the probabilistic model show a satisfactory overall correctness rate, with the hit rate far surpassing the false alarm rate in issuing flood warning for historical events. Further analyses show that the probabilistic model is effective in evaluating the level of uncertainty lying within flood warning which can be reduced by several techniques proposed in order to improve warning performance. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Optimizing water resources allocation in the Haihe River basin under groundwater sustainability constraints     

Martinsen  Grith  Liu  Suxia  Mo  Xingguo  Bauer-Gottwein  Peter 《地理学报(英文版)》2019,29(6):935-958

Journal of Geographical Sciences - This study applies a hydroeconomic optimization method for water resources management in the highly water stressed Haihe River basin. A multi-objective,...  相似文献   

A cognitive framework for road detection from high-resolution satellite images     

Naveen Chandra  Jayanta Kumar Ghosh  Ashu Sharma 《国际地球制图》2019,34(8):909-924

Road network extraction from high-resolution satellite (HRS) imagery is a complex task. It is an important field of research and is widely used in various cartographic applications such as updating and generating maps. The objective of this research work is to develop a novel framework, emulating human cognition, for detection of roads from HRS images. Roads network from HRS images are detected using support vector machines within the different stages of cognitive task analysis. In the first stage, basic information about the cognitive parameters which are required for image interpretation is collected. In the second stage, the rule-based method is used for knowledge representation. Lastly, during knowledge elicitation, the developed rules are used to extract roads from HRS images. The proposed method is validated using 16 HRS images of developed suburban, developed urban, emerging suburban and emerging urban region.  相似文献   

多星融合的土壤湿度滚动式估算模型     

梁月吉  任超  黄仪邦  王浩宇  卢献健  晏红波 《遥感学报》2019,23(4):648-660

全球定位系统干涉反射测量(GPS-IR)是一种新的遥感技术,可用于估算近地表土壤水分含量。考虑到多卫星融合的优势和土壤湿度的时空尺度性,提出一种基于多星融合的土壤湿度最小二乘支持向量机(LS-SVM)滚动式估算模型。首先通过低阶多项式拟合分离GPS卫星直射和反射信号,进而建立反射信号正弦拟合模型,获取相对延迟相位。最后,通过线性回归模型有效分析和选取多卫星相对延迟相位,并建立基于多星融合的最小二乘支持向量机模型进行滚动式估算土壤湿度。以美国板块边界观测计划PBO提供的监测数据为例,对比分析利用单颗、多颗GPS卫星进行土壤湿度滚动式估算的可行性和有效性。经理论分析和两个测站实验表明:该模型充分发挥了LS-SVM的优势,有效综合了各卫星的性能,改善了采用单颗卫星进行土壤湿度估算时,其结果极易出现异常跳变的现象;模型只需较少的建模数据,采用滚动式能实现较长时间的估算,估算误差较为稳定;模型所估算的结果与土壤湿度实测值之间的相关系数R2以及均方根误差分别为0.942和0.962、0.072和0.032,相对于部分单一卫星至少提高了18.18%。因此,土壤湿度问题可作为非线性事件处理,采用多卫星融合估算是可行和有效的。  相似文献   

Elastic-plastic analysis for pile-anchor supporting system of deep foundation pit     

JIN Yingyu  BAI Yu 《世界地质(英文版)》2009,12(4):236-240

By using numerical analysis methods to simulate the deep excavation, a lot of analyses are established on the basis of two-dimensional plane strain, ignoring the fact that foundation pit possesses three dimensions. For soil constitutive relation, people always take linear and nonlinear model, without considering the plastic behavior of soil. Using plastic-elastic hardening model to simulate constitutive relation of soil characteristics, the authors carried out mechanical analysis for pit excavation and support. The results show that the analysis for the stress state of pile anchor system is an effective way which provides theoretical basis for calculation of soil displacement.  相似文献   

中国近海海上溢油预测与应急决策支持系统研发   总被引：4，自引：0，他引：4  

安伟  王永刚  王新怡  牛志刚  赵宇鹏 《海洋科学》2010,34(11):78-83

开发了中国近海海上溢油预测与应急决策系统,由三维水动力模型、溢油风化模型、环境敏感区图和决策支持模型组成。系统能够预测海面油膜的漂移-扩散行为和风化过程,提供敏感区污染预警和资源优先保护次序、溢油应急优化方案以及溢油清污效果实时动态模拟。作为海上溢油应急反应决策平台,系统能够通过网络提供服务。  相似文献   

天津地区深基坑开挖对历史建筑的影响分析     

刘月涛  杨华伟 《岩土工程技术》2012,26(2):102-105

随着城市化进程的推进,城市中历史建筑的保护日益受到重视。城市中修建深基坑工程,不可避免的会对周边历史建筑产生影响。结合天津地区深基坑工程实例,分析了历史建筑受深基坑开挖影响的破坏机理,认为基坑周边土体不均匀沉降是引起历史建筑破坏的重要原因。同时,根据监测结果,分析了天津地区历史建筑的变形规律,探讨了减小建筑物变形的措施,可为类似工程提供参考。  相似文献   

基坑降水中的渗出面     

赵晓峰 《岩土工程技术》2012,26(3):137-140

对基坑降水中渗出面产生的机理、影响渗出面高度的因素、渗出面高度的计算、渗出面对基坑工程的危害及采取的措施等进行了详细的论述。工程实践证明,基坑降水工程中渗出面的研究对解决基坑降水中遇到的相关工程问题提供了理论依据。  相似文献   

承压水地基高层建筑基础工程施工技术分析     

郑平  吴旭君  杜甫志 《岩土工程技术》2012,26(3):159-162,F0003

论述了承压水对高层建筑基坑支护、桩基础、抗浮锚杆（桩）施工的不利影响。结合工程实例,介绍了喷射注浆止水墙处理承压水的设计方法,并分析了总施工顺序、涌水钻孔处理和地下水水位观测等关键技术问题。  相似文献