Optimum selection of design parameters for transportation of offshore structures

A probabilistic framework is presented to select the design significant wave height and design transverse rotation for typical barges used in the Gulf of Mexico for marine transportation of structural elements and/or systems. The selection of design transverse rotation is based on optimization procedure that trade-off between the performance of the barge subjected to a meteorological-oceanographic (metocean) hazard along the route and losses by structural damage. For this purpose probabilistic models to estimate the metocean hazard for marine transportation are shown. Afterwards, the design rotation is linked to the design of significant wave height and to the return period associated with such wave conditions. The formulation is applied to an offshore transportation route in the Gulf of Mexico.     

实施差异化竞争构筑企业竞争优势一种可供选择的工程咨询设计企业营销战略初探

作为企业竞争战略之一的差异化战略,强调在瞄准顾客导向的基础上形成自己独到的竞争优势,从而以己之长博对手之短。本文应用竞争战略和营销战略的理论和方法,采用营销策略作为竞争战略实施的具体策略,以保证向顾客及时传递有价值的差异性,进而从组织结构、人力资源及企业文化等方面,阐述了为实现营销战略的支持性变革。营销策略在市场和产品之间架起一座桥梁,使勘察设计院能够以市场为导向,创造价值、传递价值和实现价值。     

新疆地区不同设防水准下设计地震动关系的研究

通过分析新疆79个城市的地震危险性,获得了新疆地区50年超越概率63%(小震)、10%(中震)、2%(大震)的基岩峰值加速度及其相互比值,研究了地震环境与不同概率地震危险性分析结果之间的关系。结果表明,由中震地震动参数换算得到的小震、大震地震动参数不具备一致概率水平,不同概率水准下基岩峰值加速度的比值与地震环境密切相关。     

剪切波速对设计反应谱的影响研究

本文采用一维土层等效线性化波动理论模型,研究了3种单一均质不同土性的土层剖面,在一定范围内剪切波速变化对场地设计反应谱的影响,重点分析设计反应谱的特征周期Tg和平台值αmax的变化趋势,其结果对于指导地震安全性评价中的勘察试验工作以及提高土层地震反应计算精度具有一定的参考价值。     

International standard (ISO) on seismic actions for designing geotechnical works–An overview

The seismic performance of geotechnical works is significantly affected by ground displacement. In particular, soil–structure interaction and effects of liquefaction play major roles and pose difficult problems for engineers. An International Standard, ISO23469, is being developed for addressing these issues in a systematic manner within a consistent framework. The objective of this paper is to give an overview of this International Standard.In this International Standard, the seismic actions are determined through two stages. The first stage determines basic seismic action variables, including the earthquake ground motion at the site, the potential for earthquake-associated phenomena such as liquefaction and induced lateral ground displacement. These basic variables are used, in the second stage, for specifying the seismic actions for designing geotechnical works. In the second stage, the soil–structure interaction plays a major role. Types of analyses are classified based on a combination of static/dynamic analyses and the procedure for soil–structure interaction classified as follows:

– simplified: soil–structure interaction of a global system is modeled as an action on a substructure;

– detailed: soil–structure interaction of a global system is modeled as a coupled system.

《北京市土地利用总体规划》图集的设计与编制

阐述了<北京市土地利用总体规划>图集的设计思想.从版式开本设计、内容结构设计、地理基础底图的设计、专题内容的设计、工艺流程设计、整饰色彩设计等几个方面入手,介绍了图集的编制方法,并对FreeHand与superMap支持下的工艺流程进行了探索,希望能为其他同类图集的编制提供一些参考.     

测绘工程专业毕业设计（论文）选题质量控制

＂指导学生撰写毕业设计（论文）是实现培养目标的重要教学环节,具有不可替代的作用,‘决不能降低要求,更不能放任自流’＂[1]。毕业设计（论文）一般经过选题、过程控制和答辩等几个环节,文章结合我院测绘工程专业多年毕业设计（论文）实际,着手研究选题环节的质量控制,对提高毕业设计（论文）的质量,适应我校应用创新型学生培养方案,...     

富县龟山景区水景设计浅析

从通过对水景设计中的人本原则、生态原则和可持续发展原则的分析入手,阐述这些原则在富县龟山景区水景设计中的实际运用情况,并提出了在水景后期维护中应该注意的问题.     

Numerical analysis of large-scale surface-piercing propellers

Surface-Piercing Propellers (SPPs) are the preferred propulsion system for light to moderately loaded high-speed applications due to the high fuel efficiency. For highly loaded applications, the efficiency of SPPs tends to decrease because of the limited submerged blade area and the presence of large suction side cavities. Moreover, it is a challenge to design large-scale SPPs that can maintain reliable fatigue strength and avoid vibration issues while maximizing the propeller thrust for a given power input. In this work, three SPP designs are presented for different size Surface Effect Ships (SESs) that can attain a maximum advance speed of 25.72 m/s (50 knots). A previously developed and validated three-dimensional (3-D) coupled boundary element method-finite element method (BEM-FEM) is used for the transient hydroelastic analysis of SPPs. The method is validated by comparing the predicted hydrodynamic performance with those obtained using a vortex-lattice method (VLM) and a Reynolds Averaged Navier-Stokes (RANS) solver. The hydrodynamic and structural dynamic performance of the SPPs are presented. Finally, challenges associated with the design related analyzes of large-scale SPPs are discussed.     

南大港湿地旅游信息系统的功能模块与应用

南大港湿地旅游信息系统 (简称 NWTIS)是适应南大港湿地生态旅游需要而精心设计与开发的。系统采用 Visual Basic的语言编辑及可视化数据库管理和 Map Info的图元输出功能进行系统集成 ,开发了基于 Windows风格的 NWTIS,实现了大量属性和空间数据的查询、分析和图文显示。