平陆运河旧州江支流口泥沙淤积模拟研究

平陆运河沿线支流众多,支流泥沙进入运河淤积后会对运河通航造成不利影响。为准确反映平陆运河旧州江支流汇入口泥沙淤积情况,文章通过建立旧州江支流口内不同坡比消能措施的二维水流泥沙数学模型进行模拟研究,得到了丰水年、平水年、枯水年旧州江支流年平均淤积比,以及淤积在旧州江支流和进入运河的沙量,并分析了支流口内不同坡比消能措施对积淤量、积淤趋势及积淤分布的影响,研究成果对旧州江支流口治理具有重要工程价值。     

空隙尺寸对透水丁坝局部冲刷的影响研究

文章通过物理模型试验,采用控制变量法研究了透水丁坝不同空隙尺寸下,水流对其附近河床的局部冲刷影响。研究表明：透水丁坝的空隙尺寸能在一定程度上影响坝后冲刷情况,坝后冲刷坑深度和体积与空隙尺寸呈负相关性;坝后横向淤积宽度与纵向淤积长度随着空隙尺寸的增大而减小。     

平陆运河沙埠江支流口泥沙淤积数值模拟分析

为准确反映平陆运河沙埠江河段真实的泥沙淤积情况,文章建立平面二维水流泥沙数学模型进行模拟分析。结果表明：沙埠江支流淤积比在丰水年、平水年、枯水年平均分别约84%、79%、83%;丰水年、平水年、枯水年淤积在旧州江支流的沙量为6.69×10⁴ t、2.69×10⁴ t、2.13×10⁴ t;丰、平、枯水年进入运河的沙量为1.28×10⁴ t、0.72×10⁴ t、0.44×10⁴ t。研究成果对类似工程有参考价值。     

城镇淤积内河截污管道施工技术研究与应用

文章为解决城镇淤积内河截污干管工程安装实施过程中的问题,针对河床内管道施工进行技术攻关,通过采用一种PE管热熔焊接温度控制装置,确保了PE管的焊接质量;结合无人船对河床底进行全方位量测,及时采集分析数据,有针对性地指导管道围堰及沟槽施工。同时,采用有限元数值模拟软件(ABAQUS)进行位移分析,有效模拟验证了管道安装后偏移情况。     

微建议 微小提议 深度思考

<正>大雨过后,村民老宋从云南省昆明市海河里捞出了几条鱼,尽管只有几寸大,但周围的村民却轰动了。一年前,海河还只是一条臭水沟,多年的污染早已让海河的鱼虾绝迹。而经过天航局一年多的治理,海河得以"排毒瘦身",重新焕发生机。"海河需要‘排毒’,更需要‘瘦身’。它就像一个身体臃肿的病人,淤积在河底的黑泥犹如堆积在人体内多余的脂肪,堵     

微建议

正微小提议深度思考盾构机推进过程中扭矩大、推力大,一旦处理不好就会发生涌水涌砂以及螺旋机喷涌。如此一来,开挖面失稳、地面沉降,隧道周边及上部管线、道路及建筑物都可能发生变形、塌陷,后果不堪设想。对于中交一航局参建的哈尔滨地铁三号线体育公园站至群力第五大道站区间紧邻松花江,施工区域全部为江中泥沙淤积而成的陆地,糟糕的"富水砂层"更成为项目团队必须攻克的一道难题。     

中国古代长桥之最 安平桥

安平桥,俗称＂五里桥＂,始建于宋绍兴八年（公元1138年）,经13年建成。该桥是中古时代世界最长的梁式石桥,也是我国现存最长的海港大石桥,后因海湾淤积,成了＂陆上桥＂。原桥长811丈,约2400米,素有＂天下无桥长此桥＂的美誉。明代时,桥东的安平古镇有民族英雄郑成功家族豪宅,后被清廷所毁。此桥历经强台风、巨浪袭击和地震的破坏,曾多次重修。1961年3月成为国家第一批公布的国家重点文物保护单位。1980-1985年国家拨款进行维修,大桥原貌得以恢复。     

黄土区公路涵洞挤密桩地基处理研究

由于湿陷性黄土由于特殊的物理力学性质,若涵洞地基处理措施不当或处理深度不够,往往容易引起涵洞下沉开裂等病害。从对青海东部4条高等级公路黄土区内408座涵洞的调查结果来看,病害率较高,发生病害的涵洞共379座,病害率达92.9%,涵洞病害主要表现为浸水淤积导致的涵洞下沉、涵节错位及路面开裂等。根据现场调研的情况及规范的要求,以青海民小公路为依托,采用不同桩间距灰土挤密桩处理涵洞地基,开展现场试验对涵洞沉降进行观测。结果表明,灰土挤密桩处理后的涵洞沉降远小于换填垫层处理的涵洞沉降,而两种桩间距灰土挤密桩沉降差异较小,建议桩间距取值为1.0m~1.2m;且涵洞进出口铺砌的施工措施应予以加强。     

希望花儿开 朵朵放光彩

莘莘的学子,当你迈着矫健的步伐前行,有多少人在为你默默地祝福,有多少人在为你保驾护航,在你迈向康庄大道的途中,还有无数默默为你奉献的,素昧平生的可人儿,那些奉献大爱的人们……不见不散的约定一座大山,一架小桥,一片爱心,一次凝聚,永恒的瞬间被幸福地定格     

虽千万桥吾往矣——纪念首座“茅以升公益桥”竣工

当爱心小桥在重庆市彭水自治县竣工的那一刻,孩子们笑了,村民们笑了,志愿者们笑了,为小桥付出心血的人们都笑了。那一刻是满足,那一刻是凝聚,那一刻是传承,那一刻是心灵的共鸣。"道之所在,虽千万人吾往矣。"道之所在,虽千万桥吾往矣。修桥过程是枯燥的、艰难的,但想到人心所向的小桥能够造福一方百姓,关注小桥工程的爱心人士们都会勇往直前,     

The influence of deposit control additives on exhaust CO and HC emissions from gasoline engines (case study: Tehran)

Air pollution is the most serious environmental problem in Tehran with exhaust emissions from spark-ignition engines accounting for a major part of problem. The formation and accumulation of deposits on the internal surfaces of engines could adversely affect the exhaust emission from vehicles. It is the perception that some of fuel additives can remove these deposits due to their detergency. The Iranian Department of Environment decarbonized more that 250,000 SI engine vehicles in Tehran with the goal of reducing exhaust CO and HC emissions from gasoline engine vehicles by engine deposit removal. Here, the influence of engine deposit removal by decarbonization on the exhaust CO and HC emissions from more than 500 gasoline engine vehicles is examined. It is found that the decarbonization process could reduce the exhaust CO and HC emissions, significantly. Emissions from Peykan and Pride vehicles decreased considerably after decarbonization.     

滨州至德州高速公路单桩竖向抗压静载试验分析与计算

利用桩基自平衡测试方法的试验结果,结合桩基设计规范,分析了黄泛平原地区桩基承载力的受力特点与影响桩基承载力的主要因素。试验与分析结果表明,黄泛平原地区第四系冲积物以亚砂土、亚粘土夹粉细砂为主,多层结构居多,上层多为粘性土。此种工程地质条件下,影响桩基竖向承载力因素较多,特别是桩基施工质量与桩基混凝土浇筑对桩基竖向承载力影响较大。     

盐穴天然气地下储气库运行过程的关键技术问题

在具有岩盐矿床地质构造的地区,将天然气储存在地下含盐岩层内,实现在短期内提供高容量的储备,是目前各国普遍采用的方法。结合国外相关技术文献及部分研究成果,对盐穴储库运行过程的关键技术问题,主要包括:如何在运行过程减少溶腔的收敛性,防止水化物的形成,溶腔建腔过程形成的冷带和残留盐水对运行过程的影响;垫层气技术、运行的稳定性及注采循环中应注意的问题。文中分别进行了较详细的论述,为今后国内盐穴储库的运行研究提供依据和技术支持。     

沈阳地铁降低造价的总体思路

开展降低地铁造价的讨论具有重大的现实意义,文章以提倡建设节约型沈阳地铁为背景,对如何切实有效地降低地铁造价的总体思路进行了研究和分析,指出树立科学发展观、充分地开展项目前期研究策划工作、合理确定投资规模、加强规划控制、采用先进设计理念、设备立足国产化及地产化、加强地铁建设项目管理等是降低地铁造价的有效措施。     

稀浆封层修复技术在港区道路养管中的应用

根据天津港"美丽港口一号工程"的要求,各港区需要进行洒水降尘。南疆港区南港路由于不间断洒水,使得路面长期处于潮湿状态,沥青粗细骨料发生离散,加上大型运输车辆的往复载荷作用,局部路面出现磨损、开裂和破坏现象,破损面积不断扩大。为防止路面进一步破坏,并使修复后的路面防水、防滑、耐磨和平整,工程采用乳化沥青稀浆封层对南港路破损路段进行修复,完工后有效保证了道路的正常使用,确保人员和车辆的通行安全,获得良好的经济和社会效益。     

Parking management for promoting sustainable transport in urban neighbourhoods. A review of existing policies and challenges from a German perspective

ABSTRACT

The organisation of parking is a key challenge to more sustainable mobility in urban areas, as its pricing and availability affect the rates of private car ownership and use. However, changing parking policies is a challenging issue for local politicians and planners because residents frequently oppose changes or restrictions to conditions they have taken for granted such as on-street parking in a public space. The aim of this paper is firstly to assess how the parking policy of an urban neighbourhood can be structured to contribute to more sustainable mobility and to increase liveability in the neighbourhood. The second aim is to apply the policies reviewed to an example neighbourhood. For this purpose, we systematically reviewed academic literature and identified five types of relevant parking policies: (i) maximum parking requirements, (ii) physical detachment of residence and parking space, (iii) residential parking permits and the limitation of available parking space, (iv) performance-based pricing and (v) parking as a demand management strategy. We discovered that most research focuses on econometric models about parking and that studies rarely address the effects of parking on the quality of life in neighbourhoods. Therefore, we need further research regarding the relationship of parking and liveability. We conclude that for the implementation of such parking policies in an example neighbourhood, the municipality needs to develop a mobility vision for its city. It has to understand parking as a tool for transportation demand management to increase the acceptance of parking policy concepts and to avoid spillover problems. Finally, in the German case, as in most other countries, states and municipalities need to redesign their legal frameworks to be able to manage parking supply better and to react to changes related to digital developments and parking. The findings have implications for other European neighbourhoods regarding the transfer from research to local circumstances and applications for the whole city.     

油气管道多轮内检测数据对齐算法研究及应用

由于多轮内检测外部不确定因素和误差的共同作用,多轮间里程数据存在一定差异,难以实现管道缺陷的对齐,人工开展内检测数据对齐的工作量巨大。文中针对管道多轮内检测数据对齐算法展开研究,建立相关模型以提高数据对齐工作效率,分析了解管道动态,保障管道安全运行。将算法应用于在役天然气管道的三轮内检测数据,实现了球阀、管件、弯头、环焊缝、缺陷等特征向基线的对齐,对齐结果与基线偏差精确至0.01 m。     

Stakeholders interests,expectations, and strategies regarding the development and implementation of electric vehicles: The case of the Netherlands

In this paper, we study the strategies of the most relevant stakeholders with regard to the development and commercialization of electric vehicles (EVs) and their recharging infrastructure. Building on the perspective of socio-technical transitions, we relate the strategies of stakeholders to their current and future interests, as well as to their expectations with regard to EVs. Our analysis is based on a series of 38 semi-structured interviews with representatives of a variety of stakeholders in the Netherlands.EVs pose both opportunities and threats to various stakeholders. They therefore participate in the development of the emerging EV system, primarily in order to learn about the potential positive and negative impacts of these systems on their interests and, ultimately, to be able to grasp the opportunities and mitigate the threats. In other words, the expectations, interests, and resulting strategies of stakeholders relate to and depend upon the specific configuration of the emerging socio-technical system for electric mobility. We identify six potential conflicts of interest: the division of tasks within a public recharging infrastructure; the allocation of charging spots; the ways in which charging behavior can be influenced; the role of fast-charging, technical standards for charging equipment; and supportive policies for full-electric and plug-in hybrid vehicles.In general, the stakeholders do not seem overly concerned about either short-term returns on investments or long-term negative impacts. In this regard, the early phase of the transition can be understood as a relatively carefree phase. In order to continue the development of the emerging EV system and to keep it on the right track, however, for the foreseeable future, supportive policies will be necessary in order to provide a stable and reliable basis for further market expansion.     

What Moves Us? An Interdisciplinary Exploration of Reasons for Traveling

Abstract

We review a number of theories of motivation, and typologies of motivations, in psychological theory and in application to a variety of specific contexts, including shopping, eating, leisure, tourism, and travel. A recurring theme is the distinction between extrinsic (instrumental, utilitarian, functional) and intrinsic (autotelic, hedonic, experiential) motivations. We suggest that travel is a behavior to which intrinsic motivations apply, and that focusing exclusively on the extrinsic motivations to travel runs the risk of substantially underestimating the demand for travel, and the resistance to policies attempting to reduce it or to technologies (notably, information and communication technologies) expected to (partly) replace it. We offer a number of suggestions for improving standard travel surveys to help obtain the data needed to explore intrinsic motivations more fully. As better data become available, travel behavior models can be refined to partly account for such motivations. We believe that the resulting insights will be extremely valuable to policy-makers, planners, and behavioral scholars.     

An agent-based multimodal simulation model for capacity planning of a cross-border transit facility

Cross-border transit facilities constitute major public investment, and thus must serve the long-term needs of the communities, such as providing access to schools and businesses, contributing to a shared regional culture and lifestyle, fostering international trade, and supporting jobs for the region’s residents. Numerous studies have been conducted to evaluate the economic implications of vehicular flow delays at border crossings, however none of the studies focused on assessing cross-border flow of bus passengers and pedestrians. Since pedestrians are considered to be autonomous, intelligent, and perceptive, it is a challenging task to predict pedestrian movement and behavior in comparison to vehicular flows which follow a specific set of traffic rules. This paper presents a multiagent based multimodal simulation model to evaluate the capacity and performance of a cross-border transit facility. The significance of this research is the use of dynamic mode choice functionality in the model, which allows an individual person to make instantaneous choices between available modes of transportation. The scope of interest of the paper is limited to simulating access interface, circulation areas, ancillary and processing facilities. The developed model was calibrated to ensure realistic performance, and validated against specific performance criteria such as throughput per processing facility. In order to demonstrate the applicability of the developed simulation model, capacity and operational planning of a pedestrian transit facility was performed. The relative performance of alternative design or configuration was evaluated using the level of service criteria. Lastly, the effectiveness of each proposed capacity or operational improvement strategy was compared to the “do-nothing” scenario.