周家嘴路越江隧道管片接缝防水技术研究

针对上海周家嘴路越江盾构隧道工程防水要求高、隧道纵向变形大等难点,文章采用有限元数值模拟和试验分析等手段,对盾构隧道管片接缝防水技术进行量化分析和研究,确定了接触面应力和闭合压缩力均符合设计防水要求的弹性密封垫方案,并提出了密封垫防水槽位置优化、减少接缝错台量、加强角部防水能力等防水构造措施。结果表明,该弹性密封垫设计方案合理可行,采取的防水技术措施切实有效。     

超埋深大直径盾构管片接缝防水探讨

盾构法隧道一般修建于富含地下水的软土之中,在施工和运营中环纵缝不可避免地出现张开、错台等现象而发生渗漏。介绍了目前国内在建及建成的盾构直径超10 m以上的过河、过江、跨海盾构法隧道的接缝防水现状,分析探讨了对大直径超埋深隧道接缝防水体系的设计构想、管片密封垫截面构造设计及角部构造、防水材料的耐久性等情况。     

非固化橡胶沥青涂料在富水地层盾构隧道管片接缝防水中的应用研究

在富水地层中,盾构隧道管片接缝防水的效果影响隧道施工质量及后期运营安全,而常规措施难以满足管片接缝防水的需求。文章通过调查分析非固化橡胶沥青涂料的组成成分、非固化性能和防水机理,提出了非固化橡胶沥青涂料与橡胶密封垫相结合的盾构隧道管片接缝复合防水技术,并应用在长沙某地铁盾构隧道下穿浏阳河试验段。通过统计穿越浏阳河后的左右线隧道渗漏情况,结果表明,采用非固化橡胶沥青涂料与橡胶密封垫相结合的盾构隧道管片接缝复合防水技术,可有效减少管片接缝的渗漏率,防水效果明显。     

盾构隧道管片接缝防水技术的新认识

盾构隧道防水工程中,无论是管片接缝密封垫的材质选择、断面构造、加工工艺,还是选择设置单道或双道橡胶密封垫,都是探究的关键。根据盾构隧道接缝防水技术现状以及管片接缝防水新技术,从密封垫材质(弹性橡胶、遇水膨胀橡胶及复合橡胶)的选用及加工方式(模压、挤出微波硫化)入手,对单道、双道密封垫在不同隧道类别、不同使用条件下的应用技术进行分析研究,在对劣质密封垫或受损密封垫的取代等设计与应用提出新认识的同时,也对嵌缝、注入密封剂、传力衬垫等接缝防水或相关技术中的误区作了进一步揭示、剖析。     

苏通1000 kV交流特高压综合管廊工程盾构隧道接缝防水试验研究

淮南—南京—上海1 000 kV交流特高压苏通GIL综合管廊工程是大直径盾构法隧道与特高压输电线路的首次结合,穿越长江,隧道结构承受的最高水压达到79.8 m,是国内水压最高的盾构法隧道。结合大直径盾构隧道接缝防水实践经验和本工程特点,设计拟定了接缝防水构造与密封垫备选断面形式;分别开展通缝拼装及错缝拼装方式下管片衬砌结构防水性能数值模拟和室内试验,得出了不同错缝量、不同张开量情况下的抗水压值和装配应力,判定能否满足本工程的防水要求;最终确定了防水材料性能指标及密封垫断面结构。     

城市隧道防水技术的现状与展望

本文主要介绍了日本隧道技术专家对城市隧道防水技术的看法，内容大致包括：城市隧道防水的重要性；渗漏水等级标准及其确定方法；盾构隧道和沉管隧道防水技术（尤以接缝防水材料为主）的特点，关键以及演变过程；当前城市隧道防水的课题和前景。其中与西欧国家的有关防水技术作了详细的阐述与比较。作者还根据我国城市隧道防水工程的实践，结合自己的经验，对比作了评析、探讨。     

武汉长江隧道管片接缝防水密封垫设计与试验研究

武汉长江隧道为我国首次穿越长江江底的大型重点工程,投资巨大,工程宏伟。对于盾构隧道管片接缝防水是隧道防水的关键,直接影响到隧道的防水效果和隧道的耐久性,通过本项目的实验研究,确定了满足工程耐水压性能、装配性能要求的防水密封垫。采用国内外的理论与实践经验,进行管片接缝防水密封垫初步设计,然后模拟施工极限装配误差,对初步设计进行防水性能与装配性能实验。根据实验结果对防水密封垫断面尺寸与结构形式及材料进行优化,并最后确定满足工程要求的最优的防水密封垫设计。因此,对于管片接缝密封垫设计,通过防水性能与装配性能实验优化设计应该成为设计中的重要步骤,对保证管片密封垫防水性能及管片拼装质量具有重要的意义。     

盾构隧道防水技术应用及工艺改进

地下工程防水技术应在工程实践中不断予以改进,由此提高防水质量,使之得到持续地完善。结合湛江湾跨海盾构隧道接缝防水材料工艺设计优化,从设计和施工的角度对盾构隧道结构自防水、接缝防水及防水材料的技术现状和工艺优化进行阐述。以期通过不断优化改进,使防水技术在盾构隧道施工应用中得到进一步的发展。     

上海长江隧道衬砌接缝和连接通道的防水试验研究

结合上海长江隧道工程衬砌接缝和连接通道的防水要求,详细阐述了所展开的一系列衬砌接缝和连接通道防水试验研究的内容和过程,并分析评价了试验的结果,可供今后类似特大工程的防水研究参考。     

高速铁路盾构隧道防水设计

根据高速铁路的运营养护特点,在广深港高速铁路狮子洋隧道设计过程中提出了盾构管片接缝防水采用双道密封与分区隔断的防水技术方案.文章针对弹性密封垫防水特点,分析了弹性密封垫及分区防水的关键技术参数,并针对弹性密封垫的正常工作状态,提出了接缝的错台量、张开量及施工期沟槽修补要求.     

基于管片错台的通缝拼装盾构隧道纵向变形安全评估

以上海软土地区通缝拼装地铁盾构隧道为研究对象,根据隧道管片环缝接头处的详细构造,对管片错台模式下的隧道纵向变形进行了研究,建立了隧道纵向结构变形安全评估方法,确定了相应的控制准则和评估流程,形成了一套隧道结构纵向变形的安全评估体系.     

A Heuristic Algorithm for the Allocation of Airport Runway System Capacity

Abstract

This paper develops a heuristic algorithm for the allocation of airport runway capacity to minimise the cost of arrival and departure aircraft/flight delays. The algorithm is developed as a potential alternative to optimisation models based on linear and integer programming. The algorithm is based on heuristic (‘greedy’) criteria that closely reflect the ‘rules of thumb’ used by air traffic controllers. Using inputs such as arrival and departure demand, airport runway system capacity envelopes and cost of aircraft/flight delays, the main output minimises the cost of arrival and departure delays as well as the corresponding interdependent airport runway system arrival and departure capacity allocation. The algorithm is applied to traffic scenarios at three busy US airports. The results are used to validate the performance of the proposed heuristic algorithm against results from selected benchmarking optimisation models.     

A multi-criteria evaluation of solutions and alternatives for matching capacity to demand in an airport system: the case of London

This paper applies multi-criteria decision-making (MCDM) methods to the evaluation of solutions and alternatives for matching airport system airside (runway) capacity to demand. For such a purpose, ‘building a new runway’ is considered as the solution and candidate airports of the system as alternatives for implementing the solution. The alternative airports are characterized by their physical/spatial, operational, economic, environmental, and social performance represented by corresponding indicator systems which, after being defined and estimated under given operating scenarios, are used as evaluation attributes/criteria by the selected MCDM methods. Two MCDM methods – Simple Additive Weighting and Technique for Order of Preference by Similarity to Ideal Solution – are applied to the case of the London airport system to rank and select the preferred alternative from three candidate airports – Heathrow, Gatwick, and Stansted – for where a new runway could be built.     

Airport capacity increase via the use of braking profiles

Many airports are encountering the problem of insufficient capacity, which is particularly severe in periods of increased traffic. A large number of elements influence airport capacity, but one of the most important is runway occupancy time. This time depends on many factors, including how the landing roll procedure is performed. The procedure usually does not include the objective to minimize the runway occupancy time. This paper presents an analysis which shows that the way of braking during landing roll has an essential impact on runway throughput and thus on airport capacity. For this purpose, the landing roll simulator (named ACPENSIM) was created. It uses Petri nets and is a convenient tool for dynamic analysis of aircraft movement on the runway with given input parameters and a predetermined runway exit. Simulation experiments allowed to create a set of nominal braking profiles that have different objective functions: minimizing the runway occupancy time, minimizing noise, minimizing tire wear, maximizing passenger comfort and maximizing airport capacity as a whole. The experiments show that there is great potential to increase airport capacity by optimizing the braking procedure. It has been shown that by using the proposed braking profiles it is possible to reduce the runway occupancy time even by 50%.     

Airport obstacle surfaces

The most commonly used criteria to determine complicated airport obstacle surfaces are FAR Part 77 imaginary surfaces, TERPS, and the one engine inoperative obstacle identification surface for air carriers. For each obstacle surface there are tradeoffs encountered in our practice between the obstruction penetration and extension of runway, change of flight profile, and allowable aircraft maximum payloads. For the purposes of both airport engineering and airport planning, a better understanding of these different obstacle surfaces and their application is important. In this paper, the differences and relationships between these surfaces are addressed. The conditions for the use of each criterion are discussed. In addition, the FAA's Obstruction Evaluation / Airport Airspace Analysis (OE/AAA) process is reviewed.     

Crosswind‐based optimization of multiple runway orientations

The runway orientation must satisfy the operational requirements of aircraft for landing and takeoff. Actually, the runway orientation is the result of compromises between the airport usability (wind coverage) and additional factors, such as available land, existing obstructions, topographic difficulties, flight path interference among runways and airports, noise pollution, and other environmental impacts. Therefore, the solution of a combination of acceptable runway orientations, which avoids excessive crosswinds at least 95% of the time, as well as the optimal orientation solution, is essential to conduct those compromises in the runway orientation analysis. The objective of this paper is to develop a computer model, named the optimization of multiple runway orientations model, which is capable of simultaneously providing a combination of acceptable runway orientations, changing the allowable crosswind limit flexibly, and determining the optimal orientations of multiple runway configurations. Instead of visual estimation or geometric computation, this paper presents an analytical method for wind coverage analysis. The model is mainly running in spreadsheet and Visual Basic for Applications (VBA). The numerical example and comparison show that the optimization of multiple runway orientations model is competitively accurate and convenient in comparison with previous ones. This paper presents an up‐to‐date model for the optimization of multiple runway orientations. By combining it with the geographic information system obstructions model, it can become an essential element of a future model for airport development cost minimization that combines airfield land use, earthwork volume, and cost estimation modules. Copyright © 2013 John Wiley & Sons, Ltd.     

Evaluating the operational performance of airside and landside at Chinese airports with novel inputs

ABSTRACT

This paper evaluates the operational performance of airside and landside at Chinese airports with two novel inputs. Furthermore, the airport landside operation is decomposed into passenger-terminal operations and cargo-warehouse operations. One novel input is the capability of the runway system which is introduced into airside performance evaluation. The other novel input is cargo warehousing which is introduced into landside performance evaluation. To address multiple optimal solutions when estimating Returns to Scale in Data Envelopment Analysis, we adopted the Zhu and Shen method. This empirical study shows that neither the number of runways nor total runway length is a genuine index of runway system capability in the evaluation of airside performance. Only four airports achieved full efficiency in all eight measures while eight airports did not achieve any full efficiency. In addition, one airport did not perform well in the benchmark analysis.     

Effect of local operational constraints on runway capacity - A case study

The estimation of runway capacity is important in airport planning and operational analysis. Standard procedures for capacity determination typically assume that there is no constraint on aircraft operations and do not provide good estimates when constraints exist. This paper presents a study of runway capacity at Singapore Changi Airport in which local operational constraints are taken into account. In addition, the impacts on capacity due to marine vessel crossings in a shipping channel near the airport, and the timing for implementation of simultaneous, independent instrument approach procedures are also investigated. The levels of annual aviation demand that could be served without excessive delays to aircraft under various operating scenarios are estimated.     

上海地铁盾构隧道纵向变形分析

隧道若发生纵向变形将严重影响到隧道结构的安全。分析探讨了纵向变形的发生、变化情况以及隧道结构和防水体系所允许的纵向变形控制值。结合工程实践,对隧道发生的典型沉降曲线规律进行了深入的分析,其结论对有效控制隧道纵向变形具有指导意义。     

苏州独墅湖隧道基坑工程设计概述

通过苏州独墅湖隧道工程设计实例,论述了根据隧道不同的主体结构形式、地质情况、环境条件以及埋深所采用的围护结构形式和工艺流程,介绍了基坑施工期间环境保护措施及工程监测分析等过程。