Steffen Marx

Integral Railway B ridges in Germany

Abstract In Germany, integral bridges for railway lines take a higher level of relevance. This paper describes the recent development of structures with integral abutments and gives an outlook on large bridges currently in the making on newly built railway lines. In the German railway network, reinforced concrete frames for spans up to 20 m have been used for more than 25 years. Lateral launching of frame bridges into existing railway links are an economical option. Following the good experience with frame construction, even longer frame bridges with integral abutments were implemented as an economical variant. The advantages are highlighted by the examples of viaduct Rednitztal, the flying junction Dresdner Bahn and the composite bridge over River Saaleflut. On the basis of these successful experiences, especially regarding low-cost construction, robust construction type and simple maintenance, these bridges are also integrated into newly built railway lines. The starting point for the construction of frame bridges was the very high-quality design of the frames compared with the single-span girder bridges implemented until then. The bridges on the railway line from Erfurt to Halle/Leipzig, which are currently in progress, are good examples for this implementation. The viaducts Scherkonde, Unstruttal, Gänsebachtal and Stöbnitztal portray in detail the design and construction principles for long frame bridges. In conclusion, the advantages of frame bridges, such as high stiffness, favourable transmission of horizontal loads and simple construction without bearings, are discussed comprehensively and quality is assessed on the basis of the gathered experience.

A Brief Review of Developments and Challenges for High-speed Rail Bridges in China and Germany

Abstract China and Germany are countries with a lot of experience in the construction of high-speed railway (HSR) bridges. Standardized design and construction of railway bridges has promoted the initial success of rapidly establishing HSRs in these two countries. Nevertheless, the continued development of HSR bridges brings new challenges to design concepts and engineering technologies. This paper briefly reviews the recent practices of HSR bridges in China and Germany, and summarizes the development of track structures and bridges. The integral design concept of the track–bridge system is presented. Thereinto, continuous ballastless track and integral bridges are introduced. The development trends of HSR bridges—including longer spans, lighter structures and faster train operating speeds—are also discussed.

Shrinkage and Expansion Strains in Self-compacting Concrete: Comparison of Methods of Measurements

The focus of the paper is to assess various methods for strain measurements in expansive concrete. The research objective was to determine strains in concrete due to its expansion.

Design Criteria for Piers of Semi-integral Bridges: Investigations on Normal Force and Reinforcement Ratio

The design of semi-integral bridges is a challenging task for planning engineers. Most components of semi-integral bridges are connected monolithically, and many parameters influence their structural behavior. This paper deals with the piers of semi-integral bridges and their monolithic connection to the superstructure. Simple design rules for conventional bridges, such as “more reinforcement, more safety” are not valid for such interactive structures. In a monolithic connection no free deformation is permitted, and constraint forces and moments occur as a result. The magnitude of the constraint forces and moments primarily depends on the stiffness of the structure, which is influenced by several parameters. In this paper, two parameters are investigated: the normal force, which influences the cracking state of the cross section and the reinforcement ratio.