Steel railway bridges as a legacy of high modernity - Foundations for a holistic decision making between repair and renewal

德国联邦铁路公司根据“Verkehrswende”日益增长的需求对其铁路网进行升级，是德国未来十年基础设施发展最重要的项目。现代化项目还直接影响到自19世纪末以来建造的大量钢制铁路桥，在此期间，这些铁路桥往往已达到其“名义”寿命。特别是在古迹部门，关于更新或修缮和加固的决定通常是根据比较评估矩阵作出的，迄今为止，比较评估矩阵几乎完全是基于技术和经济标准。另一方面，文化或生态标准不被考虑，或者至多作为一笔总和包括在内。一方面，缺乏合理考虑后一种标准的可靠依据；另一方面，技术和经济领域的定量评估很难与更定性的评估相比较，特别是在建筑文化领域。在这种背景下，该项目旨在为钢桥整体评估提供可靠的方法基础，其中所提到的四个标准都得到了充分和可比较的考虑。重点不是对现有桥梁的评估，而是它们使用历史上的一个中心点--在某个阶段决定维护或更新它们。关键不是“产品”建设，而是在这些基本选择之间作出选择的过程。对于技术、经济、生态和建筑文化等维度，首先制定可比较的评价指标，然后将这些指标结合在一个整体评价体系中。第一个重点是通过在内容和概念方面扩展现有的评估方法，详细说明和阐述生态和建筑文化标准。第二个重点是比较制定一个尽可能有效的总体评价制度。为此将开发两个变种，可以在DB Netz AG桥梁建设项目的案例研究中的第三个重点中进行测试、比较和改进。所获得的知识为实施有充分依据的评估系统并在此基础上在实际工作中实施适当的行动战略提供了可能性。该项目由英国电信大学科特布斯-森夫滕贝格(Werner Lorenz)建筑史名誉教授(Werner Lorenz)和伍珀塔尔大学(Felix Huber)环境相容基础设施规划系合作实施。

The upgrade of Deutsche Bahn's rail network according to the growing demands of the "Verkehrswende" is the most important project of German infrastructure development in the coming decade. The modernization project also directly affects the still large number of steel railway bridges built since the end of the 19th century, which in the meantime have often reached their “nominal” lifespan. Particularly in the monument sector, the decision on renewal or repair and strengthening is usually made on the basis of comparative assessment matrices, which so far have almost exclusively been based on technical and economic criteria. Cultural or ecological criteria, on the other hand, are not taken into account or are at most included as a lump sum. On the one hand, there is a lack of reliable foundations for an appropriate consideration of the latter criteria; on the other hand, the quantitatively fixable evaluations in the technical and economic fields can hardly be compared with the more qualitative evaluations, especially in the field of building culture.Against this background, the project aims to provide the basis for a robust methodology for the holistic assessment of steel bridges, in which all four criteria mentioned are adequately and comparably taken into account. The focus is not on the evaluation of existing bridges, but on a central point in their use history - the decision to maintain or renew them at a certain stage. It is not the "product" construction that is at stake, but the process of making the decision between these basic options.For the dimensions of technology, economy, ecology and building culture, comparable evaluation keys are first developed, which are then combined in an overall evaluation system. The first focus is on the specification and elaboration of ecological and building culture criteria by extending existing evaluation approaches in terms of content and concept. A second focal point is the comparative formulation of an overall evaluation system that is as efficient as possible. Two variants will be developed for this, which can be tested, compared and sharpened in the third focus in case studies on bridge construction projects of DB Netz AG. The knowledge gained opens up the possibility of implementing a well-founded evaluation system and, building on this, appropriate action strategies in practical routines.The project is carried out in cooperation between the honorary professorship for Construction History at the BTU Cottbus-Senftenberg (Werner Lorenz) and the department of Environmentally Compatible Infrastructure Planning at the University of Wuppertal (Felix Huber).