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Resilient rail infrastructure: dissipation driven fracture analysis of concrete support systems

弹性铁路基础设施：混凝土支撑系统的耗散驱动断裂分析

基本信息

批准号：
EP/M017494/1
负责人：
William Coombs
金额：
$ 24万
依托单位：
Durham University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2015
资助国家：
英国
起止时间：
2015 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FM017494%2F1
关键词：
Resilient rail infrastructure dissipation driven

项目摘要

The UK's rail infrastructure currently supports 1.3 billion passenger journeys and 100 million tonnes of freight each year. The freight transport alone contributes £870 million to the UK economy. The sector has seen 40% and 60% increases in passengers and freight over the last 10 years, respectively, and it is expected that passenger numbers will double and freight increase by 140% over the next 30 years. As the network has developed the magnitude and frequency of loads applied to the rail support systems have increased significantly, even over the last 10 years. It is estimated that between 2009 and 2014, the UK's rail operator, Network Rail (NR), will invest £3.75bn in track to maintain the network. The vast majority of this 32,000km of rail infrastructure is supported by pre-stressed concrete sleepers (PCSs) and crossing bearers (CBs). These concrete members provide lateral restraint and vertical support to the running steel rails. The PCSs and CBs are in turn supported on three sides by track ballast; crushed stone 30-50mm in diameter. Since their introduction in the 1950s, PCSs have superseded traditional wooden sleepers in new track and NR replaces approximately 200,000 timber sleepers each year with PCSs. However, despite the reliance of the UK's rail network on these concrete structures, and the simplicity of their geometry, surprisingly their structural behaviour is poorly understood. NR's CP5 delivery plan estimated that the used life of the sleepers supporting the network for the 2013/14 period is 60.9% and that 5,918 track failures would occur during the same timeframe. There are concerns that the development of fractures in concrete supporting members is undermining the rail network. In order to maintain a safe, reliable and resilient rail network it is essential to understand how the concrete support systems can be designed to future proof them against ever increasing structural demands.The proposed research is concerned with three-dimensional dynamic analysis to assess the structural robustness of PCSs and CBs using a novel computational mechanics framework and associated numerical analysis technique. If successful, this research will provide a transformative, complete and consistent framework for modelling fracture in a variety of engineering materials. The creativity of this proposal lies in the application of up-to-the-minute ideas in constitutive modelling, fracture mechanics and numerical analysis techniques to a poorly understood yet critical component of the UK's rail infrastructure. It will provide a framework within which to develop new resilient rail-support system fastening methods.

英国的铁路基础设施目前每年支持13亿人次的客运和1亿吨的货运。仅货运就为英国经济贡献了8.7亿英镑。过去10年，该行业的客运和货运量分别增长了40%和60%，预计未来30年客运量将翻一番，货运量将增长140%。随着铁路网的发展，施加在轨道支撑系统上的荷载的幅度和频率显著增加，甚至在过去10年中也是如此。据估计，在2009年至2014年期间，英国铁路运营商网络铁路（NR）将投资37.5亿英镑用于轨道维护。这32，000公里的铁路基础设施中的绝大多数由预应力混凝土轨枕（PCS）和交叉支座（CB）支撑。这些混凝土构件为运行中的钢轨提供横向约束和垂直支撑。PCS和CB依次由轨道道碴（直径为30- 50 mm的碎石）在三个侧面支撑。自20世纪50年代引入以来，PCS已取代新轨道中的传统木制轨枕，NR每年用PCS取代约200，000个木制轨枕。然而，尽管英国的铁路网络依赖于这些混凝土结构，而且它们的几何形状很简单，但令人惊讶的是，它们的结构行为却知之甚少。NR的CP 5交付计划估计，2013/14年期间支持网络的轨枕的使用寿命为60.9%，在同一时间段内将发生5，918次轨道故障。有人担心，混凝土支撑构件的裂缝正在破坏铁路网。为了保持一个安全，可靠和有弹性的铁路网络，它是必不可少的，以了解如何混凝土支撑系统的设计，以证明他们对不断增长的结构demands.The建议的研究是有关的三维动态分析，以评估的结构鲁棒性的PCS和CB使用一种新的计算力学框架和相关的数值分析技术。如果成功，这项研究将为各种工程材料的断裂建模提供一个变革性的，完整的和一致的框架。该提案的创造性在于将本构建模、断裂力学和数值分析技术中的最新思想应用于英国铁路基础设施的一个鲜为人知但至关重要的组成部分。它将提供一个框架，在其中开发新的弹性轨道支撑系统紧固方法。