Preliminary results of an analysis of areas of influence in Shanghai

The main deficiency of most current modeling approaches to transportation can be identified as neglect of the integration of existing geographical knowledge in regard to the ex ante transport/land use modeling approaches, with its focus on territorial dynamics and theory development. This paper addresses this aspect of the problem by introducing a theoretical and methodological framework for the analysis of the interrelationship between land uses. The analysis attempts to determine to what extent the functional land use in a city can be considered an ordered pattern. The order sought does not rely on purely spatial configurations, but on the correlation of transportation and land use. The first section of this paper focuses on theoretical considerations. It stresses the fact that conventional approaches do not apply in the present context. It then suggests an alternative based on areas of influence and measured in terms of level of attractance of land uses. The second describes a procedure based on this alternative following the remarkable contribution of Hanjoul, Beguin and Thill. An application of this procedure to the analysis of Shanghai is then examined. Finally, an evaluation of the strategies for optimizing the interrelationship between land uses is presented. The paper concludes with a possible research agenda.     

BOTDR传感技术在桥梁移动荷载识别中的应用

文章针对我国桥梁移动荷载识别的测试技术还不能实现有效识别的现状,对应用BOTDR技术的可行性进行分析,表明BOT-DR技术用于桥梁移动荷载的识别具有广阔的前景。     

Evaluation of a public transportation level of service concept

The level of service of a bus line is evaluated by its operational characteristics, particularly by the ratio between average bus travel time on a given route and the average passenger car travel time on the shortest distance between the origin and the destination of the bus in question. It is shown that the level-of-service measure may be predicted by such independent variables as route length, average distance between bus stations, number of signalized and unsignalized intersections, and the ratio between such intersections. It is hypothesized that use of other independent variables such as boarding and alighting passengers, or volume to capacity ratio on the route concerned, could improve the predictive power of the suggested models. Further research is recommended on the effect of these latter variables and other operational variables which might influence bus level of service, and also on the comparison between direct bus lines and lines which use transfer points.     

燃油税费改革对广西道路货运的影响研究

文章阐述了燃油税费改革的目的及意义,介绍了广西道路货物运输的基本情况,并依托大量调查统计资料,对比分析了燃油税费改革对广西道路货物运输市场、运输成本及企业管理的影响,提出了调整公路货运企业运输车辆组成结构,建立公路货物运输信息交易平台和探索新型公路货运企业经营模式的对策措施。     

锦屏二级水电站交叉隧洞模型试验研究

多洞室交叉处围岩力学状况目前国内外研究相对较少。文章以锦屏二级水电站3#引水隧洞三洞交叉段为工程背景,为了解交叉洞室对围岩的影响,进行了三维地质力学模型试验;通过两组试验,有效地揭露了交叉洞室间的相互影响,以及开挖与支护方法对围岩稳定性的影响。最后通过超载试验,确定了交叉洞室的破坏模式及其破坏过程;试验结果为指导施工提供了依据。     

盾构施工对环境的影响

由于各种原因,盾构施工造成严重影响环境的事故仍时有发生。综合国内外学者为减少乃至杜绝类似事故阐述的观点,并结合上海地铁施工的经验,提出了盾构施工对环境影响的程度、对环境影响的机理以及盾构施工如何对环境影响最小化等方面的分析和建议。     

超前小导管注浆布置范围对地铁隧道开挖的影响分析

针对施工中的沈阳地铁工程,开展了超前小导管预注浆环向布置范围对地铁隧道开挖的影响分析.模拟不同的小导管环向布置,对围岩应力、隧道各监测点位移进行综合比较,确定出超前小导管合理布置范围,对类似隧道工程有较大参考价值.     

层间作用对水泥混凝土路面温度应力的影响分析

文章介绍了水泥混凝土路面温度应力的形成机理和计算理论,分析了层间作用对水泥混凝土路面温度应力的影响,为进一步揭示由温度应力引起的路面破坏的原因提供理论依据。     

The effects of on‐street parking on the service rate of nearby intersections

An on‐street parking maneuver can often start a temporary bottleneck, leading to additional delay endured by the following vehicles. If the maneuver occurs near a signalized intersection, the service rate of the intersection might be reduced. In this paper, a model is built to analyze the effects of parking maneuvers on the intersection service rate. Based on the hydrodynamic theory of traffic flow, the perturbation caused by the parking maneuver is analyzed. Using dimensional analysis, we illustrate the relation between the background conditions, the distance from the parking area to the intersection, and the intersection service rate. Based on this relation, one can compute the service rate reduction caused by existing on‐street parking areas. A minimum distance between the parking area and the intersection to avoid such reduction can be accordingly found. Numerical examples based on empirical data from the city of Zurich, Switzerland, are provided to illustrate the practical applications. Although the analysis is based on streets with a single lane per direction, the findings can provide some insights regarding different situations. We hope such findings can be used as a basis for developing on‐street parking design guidelines. Copyright © 2015 John Wiley & Sons, Ltd.     

射流泵外特性的CFD模拟

针对射流泵基本理论研究方面存在的问题,应用计算流体力学(CFD)中PHOENICS软件建立射流泵几何模型,采用正交非等距网格划分方法,模拟射流泵的内部湍流场,研究了流量比、喉嘴距对速度的影响,以及喉嘴距对湍动能的分布影响,得出射流泵基本性能曲线,与文献给出结果吻合较好.完善了射流泵的基本特性研究,分析了射流泵流场中能量...