独立小容量供电系统瞬时脉冲型谐波分析研究

介绍了独立小容量供电系统的特点并针对供电系统中常见的几种瞬时脉冲型谐波进行了分析,仿真结果表明瞬时脉冲型谐波对小容量供电系统的影响应予以考虑。     

营口港鲅鱼圈港区码头船舶岸电系统的设计

基于对国内、外港口船舶岸电系统应用情况的分析,阐述在港口码头设置船舶岸电系统对节能减排和环境保护的意义和必要性。结合营口港鲅鱼圈港区码头船舶岸电系统的设计方案,重点介绍港口船舶岸电系统的基本设计原则,对各种用电负荷的计算步骤、设备选型和系统功能等加以说明,可供今后港口船舶岸电系统的设计参考。     

螺旋钢桩抗拔特性的现场试验研究

根据螺旋钢桩现场抗拔试验中61根试验桩的监测数据绘制Q—S曲线,推算各类桩型的平均极限承载力,分析桩长、叶片数量、叶片间距、首层叶片埋深、叶片直径等参数对螺旋钢桩极限抗拔承载力的影响,试验结果表明螺旋钢桩的极限抗拔承载力随桩长和叶片直径而增加,叶片间距和首层叶片的埋深均存在临界点。分别通过慢速加载法和快速拉拔法测试螺旋钢桩桩极限抗拔承载力,快速拉拔法测得的极限承载力平均值约为慢速加载法极限承载力的2．0倍。     

无覆盖层嵌岩桩承载性状的有限元分析

文章采用有限元软件ABAQUS建立简化后的桩一岩三维实体有限元模型,分析了岩层坡度变化对嵌岩桩承载性状的影响,并研究了嵌岩深度和桩身强度对陡峭岩层嵌岩桩承载力的影响。计算结果表明：当岩层倾斜角较大时,岩层倾角的变化对桩的承载能力影响显著;但当岩层坡度较缓,且缓于一定坡度比时,岩层倾角的变化对桩承载性状影响甚微;适当加大桩身混凝土强度等级可以提高陡峭岩层上桩基的承载能力,而增大桩基嵌岩深度对桩承载能力的提高影响不大。     

Analysis of Work Zone Traffic Behavior for Planning Applications

Abstract

Understanding work zone traffic behavior is important for the planning and operation of work zones. The objective of this paper is to develop a mathematical model of work zone traffic flow elements by analyzing the relationships between speed, flow, and density that can be used to estimate the capacity of work zones. Traffic flow data were collected from 22 work zone sites on South Carolina interstate highways. The scatter plots of the collected data demonstrate that the relationship between speed and density does not follow Greenshields’ linear model. A non-linear hyperbolic model was developed to describe the relationship between speed and density. Using this model the capacity of a work zone was estimated to be 1550 passenger cars per hour for 2-lane to 1-lane closures. Adjustments to this capacity value to consider other types of vehicle as well as the work zone intensity are provided. Highway agencies can use this estimated capacity along with anticipated traffic demand to schedule work zone operations to avoid long periods of over-saturation.

The tapered approach to work zone lane closures used by South Carolina is similar to methods used in work zones throughout the world. The authors believe that the methodology described in this paper for modeling work zone traffic as well as estimating work zone capacity is transferable to other countries. The conversion of actual volumes to passenger car equivalents may have to be modified due to the significant differences in traffic makeup between the United States and other countries.     

南海固定式平台极限承载能力分析

针对南海海域环境荷载下服役的固定式平台,以一固定式导管架平台为例,运用基于ANSYS软件的单元替换法分析计算该平台无缺陷情况下和有腐蚀、海生物附着、构件缺失等损伤情况下的极限承载能力,验证了计算正确性和可行性.     

上港集团扩大后方堆场能力浅析

为推进上海"国际航运中心"建设,上港集团挖掘自身潜力,对堆场进行了改扩建。介绍上海国际航运中心建设的情况。分析上海港的发展情况和港区主要装卸工艺及现有矛盾。着重介绍上港集团一些公司改扩建堆场的做法。该举措有效提高了集团的生产能力。     

煤炭码头年通过能力的一种神经网络分析方法

为提高秦皇岛港煤炭码头通过能力,引入神经网络分析方法。分别介绍原有通过能力分析方法和煤炭码头通过能力神经网络分析法。经分析,寻找出煤炭码头的年通过能力瓶颈,有效地辅助码头运营管理者进行管理和决策。     

Quality indicators and capacity calculation for RoRo terminals

Abstract

Road freight transportation has increased dramatically over recent years along with its impacts such as congestion, noise, and pollution. As a result, European and US governments have started policies to promote alternatives to road transportation, such as logistic chains containing a Short Sea Shipping (SSS) link. Road is, by definition, a more flexible means of transportation than shipping, which is usually cheaper. Therefore, to move traffic to SSS chains, it is necessary to provide fast, frequent, and reliable maritime transportation. In this sense, roll-on/roll-off (RoRo) vessels are the most convenient ships to be used, since they have smaller dwell times in port and, therefore, this is a kind of traffic likely to increase dramatically. The foreseeable increase of this kind of traffic must meet with an increase in the actual capacity by means of either improvement in performance and possible enlargements of existing terminals or the construction of new terminals. In that sense, this paper proposes a simple methodology to calculate the capacity of a RoRo terminal, whether already in operation or during its design process, and relate it to some quality standards by means of quality indicators, which should lead to the definition of Levels of Service similar to those already used in roads and airports. The paper ends by applying the methodology to a real terminal in Barcelona, Spain.     

站城融合模式下既有铁路车站城市功能开发体量预测研究

针对站城融合模式,提出对既有铁路车站及其影响区域的城市功能开发体量预测方法.考虑车站周边道路交通剩余能力和城市规划中对土地容积率的要求,协调枢纽城市功能和交通功能体量的比例关系,建立铁路既有车站城市功能的体量预测模型,并利用商业求解器对模型求解,得到各业态开发总体量的范围.以重庆沙坪坝综合交通枢纽城市功能开发为例,检验求解结果与实际开发体量的契合度及有效性.分析枢纽交通功能占比和容积率的敏感性,验证模型的适用性.计算结果表明,本文方法能有效利用道路承载能力,在适应城市整体发展要求的情况下,实现枢纽和土地的一体化发展,为投资者加强土地集约开发提供新思路.