深基坑围护结构中SMW工法桩施工工艺研究

为了提高深基坑围护结构施工质量,以广东省珠三角城际轨道交通琶洲支线工程为例,分析深基坑围护结构中SMW工法桩的特征,提出应用SMW工法桩施工工艺的施工方法,以期为同类型施工提供参考。     

大直径SMW工法设计与施工关键技术分析

深基坑支护设计,不仅要保证基坑内的正常作业,而且要防止基坑及坑外土体的移动,确保基坑附近建筑物、道路、管线等的正常使用.因此,深基坑围护结构的安全性显得尤为重要.在众多围护方法中,SMW工法(型钢水泥土搅拌墙)以其适用性强、围护成本低、施工周期短而倍受关注.文章结合工程实践,对大直径SMW工法在软土地基深基坑支护中的支护结构设计及施工要点及难点进行了分析和探讨.     

SMW工法深基坑支护设计浅探

在众多深基坑围护方法中,SMW工法以其适用性强、围护成本低、施工周期短而倍受关注。结合SMW工法设计、施工的一个实例,对上海软土地基SMW工法深基坑支护设计的技术进行一些粗浅的探讨。     

杭州西湖隧道工程结构设计

杭州西湖隧道工程采用水泥土搅拌桩内插H型钢作为围护结构(即SMW工法),该工法是首次在杭州市应用,为该工法的进一步推广提供了更有力的设计依据和宝贵的施工经验。     

在线监测系统的创建及其在搅拌桩施工质量管理中的应用

依托某基坑工程,对SMW工法桩和搅拌桩进行施工质量监测系统的现场试验研究,建立一套能够进行监测数据自动采集、实时传输和远程平台管理的在线监测系统。试验成果显示,该系统能实时采集相关质量控制指标,通过无线传输实现远程平台的数据汇总、存储和分析,并对异常数据进行实时报警;依托工程的现场试验,验证了该系统的适用性,能有效地提高搅拌桩的施工质量,降低基坑事故风险,满足工程技术要求。     

深基坑支护中的SMW工法

SMW工法是近年来兴起的一种新的深基坑围护形式,由于其具有无渗漏水、造价低等诸多优点,已得到越来越广泛的应用。文章结合工程实例,介绍SMW工法施工工艺及其操作要点,供同类型施工参考。     

SMW工法在浦东南路——张杨路下立交深基坑工程中的应用

结合上海某下立交的基坑工程设计与施工，分析SMW工法围护的基坑开挖引起的变形以及对周围环境的影响，为SMW工法这一集挡土、止水两大功能于一体的新型围护结构在上海软土地区的推广应用积累经验。     

SMW工法在南京地铁围护工程中的应用

SMW围护施工工法国外应用较多,目前在国内处于推广阶段.文章介绍了在南京地铁珠江路车站围护工程施工中SMW工法的应用情况,用工程实例说明了此工法在大型、超深基坑围护工程中应用的可行性.     

SMW工法在基坑围护结构中的应用

SMW工法是在水泥搅拌桩内插入H型钢或其它种类的受拉材料,形成受力和防水的复合结构.该结构具有止水性能好,施工工期短,施工简单、方便,工程投资省等优点.通过工程事例重点介绍如何进行SMW工法设计,提出施工注意事项.     

SMW工法在城市快速通道建设中的应用

结合南京某工程,介绍了SMW工法在施工中应引起注意的几个问题,阐述该工法造价低、工期短、材料循环利用、环境影响小等方面的特点,提出结合工程实际,适当加大SMW工法桩桩长的观点。     

Willingness-to-pay for infrastructure investments for alternative fuel vehicles

This study investigates potential demand for infrastructure investment for alternative fuel vehicles by applying stated preference methods to a Japanese sample. The potential demand is estimated on the basis of how much people are willing to pay for alternative fuel vehicles under various refueling scenarios. Using the estimated parameters, the economic efficiency of establishing battery-exchange stations for electric vehicles is examined. The results indicate that infrastructural development of battery-exchange stations can be efficient when electric vehicle sales exceed 5.63% of all new vehicle sales. Further, we find a complementary relationship between the cruising ranges of alternative fuel vehicles and the infrastructure established.     

A procedure for estimating transit subsidization requirements for developing countries

The paper presents a procedure that has been developed for estimating subsidization requirements for urban transit services in developing countries. The procedure is based on a subsidization policy of reducing transport expenditure burden on the average commuter, by maintaining his transport expenditure-income ratio at a reasonable level. It is designed for both regulated and deregulated transport markets. It requires, as input, historical data (previous year) on fare, productivity, and load factor for the transport service or mode concerned, the transport expenditure-income ratio distribution of the commuters, and the current level of commuter personal transport allowance. It is based on the premise that transport expenditure-income ratio is inversely related to income. The subsidization formula developed in the paper yields a level of subsidy that is commensurate with the level of control a government is able to exercise over transit operations.     

A methodology for classification by priority for action: Selecting road stretches for network noise action plans

Road traffic noise is an element of outstanding importance within the overall context of environmental impact. This problem must be technically addressed from an efficient viewpoint, and solutions or alternatives should be considered by means of appropriate and consolidated procedures.Up to now, there is no regulated guideline for establishing well-founded priorities when dealing with the diverse road stretches included in the corresponding Action Plans against noise under the Environmental Noise Directive (2002/49/EC). To this end, the present study proposes a methodology to sort, by priority, road stretches identified by their noise problems and therefore requiring appropriate action. The methodology is based on the so-called “road stretch priority index” (henceforth referred to as RSPI). This index involves a number of variables (called “road stretch priority variables”) that are weighted according to their influence on the road traffic noise problem. Thus, the RSPI makes it possible to prioritize different stretches of the Action Plan. To illustrate the application of the proposed methodology, this paper also describes a real case entailing a difficult choice, applying the proposed methodology to a review of the Action Plan against Noise 2008–2012 in the province of Almería, for the road network of the regional government of Andalusia, Spain.     

Routing and charging locations for electric vehicles for intercity trips

This study addresses two problems in the context of battery electric vehicles (EVs) for intercity trips: the EV routing problem and the EV optimal charging station location problem (CSLP). The paper shows that EV routing on the shortest path subject to range feasibility for one origin–destination (O–D) pair, called the shortest walk problem (SWP), as well as a stronger version of the problem – the p-stop limited SWP – can be reduced to solving the shortest path problem on an auxiliary network. The paper then addresses optimal CSLPs in which EVs are range feasible with and without p-stops. We formulate the models as mixed-integer multi-commodity flow problems on the same auxiliary network without path and relay pattern enumeration. Benders decomposition is used to propose an exact solution approach. Numerical experiments are conducted using the Indiana state network.     

A methodology for assessing eco-cruise control for passenger vehicles

This paper compares and assesses fuel consumption models, cost functions, and solution methods, as they all have an influence on the resulting profile and associated fuel savings of an eco-cruise control system for passenger vehicles. An eco-cruise control system uses road topographical data obtained from a high-resolution digital map to control the vehicle velocity to optimize its fuel consumption. The optimal velocity profile is the result of an optimal control problem.     

Well-to-wheel analysis for electric, diesel and hydrogen traction for railways

This paper derives the energy efficiencies and CO₂ emissions for electric, diesel and hydrogen traction for railway vehicles on a well-to-wheel basis, using the low heating value and high heating value of the enthalpy of oxidation of the fuel. The tank-to-wheel and well-to-tank efficiency are determined. Gaseous hydrogen has a WTW efficiency of 25% low heating value, if produced from methane and used in a fuel cell. This efficiency is similar to diesel and electric traction in the UK, US, and California. A reduction of about 19% in CO₂ is achieved when hydrogen gas is used in a fuel cell compared to diesel traction, and a 3% reduction compared to US electricity.     

城市交叉口交通拥挤最大排队长度估算模型

文章针对交通波模型应用于城市道路排队长度估算所存在的问题，评述了累计到达-离去模型应用的优势。通过对累计到达-离去模型的三种变形形式的分析比较，选用出其中的一种模型为基础模型进行改进，得到城市交叉口交通拥挤最大排队长度估算模型，并通过VISSIM仿真实验验证了这一改进模型的实用性。     

Planning for implementation

Although the urban transportation planning process has evolved into the most sophisticated of all urban planning processes, the increasirig difficulty in implementing long-range transportation plans in urban areas today suggests basic questions concerning the process which deserve critical examination.Planning for implementation of urban transportation programs, particularly during periods of rapidly changing human values, requires a continuing re-evaluation of both technical and organizational strategies and their interrelationships.This paper raises some fundamental questions about the traditional activities and relationships that have characterized most urban transportation planning programs in the past. It also suggests a number of strategies, both technical and organizational, that may contribute to the implementation of plans and programs resulting from the transportation planning process.The first portion of this paper discusses the implications of not providing transportation services to match metropolitan growth. The experience of the Washington Metropolitan Area over the past decade is used to illustrate these implications.A discussion of organizational and institutional constraints upon the planning process follows. Then, the implications for the planning process are explored, and the scale of planning is reviewed as well as the need for monitoring the performance and impact of facilities.Next, the paper deals with the need to broaden the range of solutions to transportation problems, including consideration of economic and land development policies to reduce travel demand, as well as the provision of new facilities.Finally, techniques for involving decision-makers in the planning process are discussed. Examples of special project activities in the Washington area are used to illustrate these techniques and their value.