Papers by Keyword: Footbridge

Abstract: The topic of medium-span bridges combined with longitudinal segmentation of the structure using precast components made of UHPC material was a challenge for the grant research team. The researchers' goal was to optimize the shape of the parapet beam from both a structural and architectural perspective. It was necessary to find the most suitable solution for connecting the beams to the bridge deck and to design the technology for manufacturing the individual structural elements and connecting them into a single functional unit. All this had to be done with an emphasis on maintaining the required parameters for safe and secure operation of the structure.The article presents a new Medium Span Footbridge System (MSFS) with a span of up to 30 meters. The system consists of a combination of parapet beams with longitudinal prestressing, ribbed bridge deck slabs, and grout joints. The article mentions the static analysis of the structure. The method of manufacturing individual parts is documented, together with the specific procedure for constructing the footbridge, which is designed to minimize work on the construction site while minimizing traffic restrictions under the footbridge under construction. The article also presents a functional sample of the structure – the first medium-span footbridge (MSF) made of UHPC with a span of 26.0 m and a clear width of 3.0 m.

Abstract: Stainless steel reinforcement in the form of prestressing wires and ropes, commonly used to reinforce prestressed concrete structures [1], is also used for suspension strips of footbridge bridges. After the accident of some of them, these structures became the subject of an examination of their current state and analyses of the origin and development of corrosion of the prestressing reinforcement used. The issue of the service life of prestressed structures is related, among other things, to their structural arrangement and the construction procedure used. As with most existing prestressed structures, the anti-corrosion protection of the reinforcement has traditionally been ensured primarily by the alkalinity of the environment, ie by concreting or grouting prestressed elements in the pipeline [2].

Abstract: The publication outlines the issue of the experimental determination of modal parameters of structures using a method called operational modal analysis. The principle of the method and possible approaches of calculation of modal parameters are presented. An example of the method’s application is the determination of mode shapes and frequencies of the repaired footbridge in Kroměříž where the dynamic test was performed twice – before and after reinforcement of the structure. The results of both dynamic tests and their comparisons with the results of the calculation model performed in the ANSYS environment are presented in this article. Additionally, and integral to this article is a description of the completed footbridge reconstruction.

Abstract: The paper deals with the design and development of a new and progressive structural types of footbridges with an external tendon used as a main load bearing member. Main goals of the paper are checking the possibilities of using such structures for many different spatial arrangements and especially identifying the problematic aspects of the design. Using the results of research conducted in previous years, the procedure for finding the optimal shape of the cable was described in detail. For specific examples the process of cable shape optimizations is shown. In the next part the influence of various boundary conditions is discussed. The structures were also checked in terms of ULS and SLS limit states. Particular attention is paid to the buckling analysis of the struts and stress distribution in the deck part. The structures were modeled using FEM software Midas Civil. The models used for basic analysis consist of beam and truss elements. For precise analysis the shell models were used. Finally the dynamic behavior analysis was performed according to SÉTRA methodology. The results and outputs of the research should be used by designers who have to deal with similar structural types and they shall hopefully help to identify the most problematic features.

Abstract: This article presents a mix design, preparation and production of thin-walled footbridge made from UHPFRC. Optimization of UHPFRC matrix and parameters of this material leads to the design of very thin structures. In this case an experimental pedestrian bridge was designed and prepared. Single-span bridge with span of 10 m and the clear width of 1.50 m with the total thickness of shell structure 30 - 45 mm was cast as a prefabricated element in one piece. Self-compacting character of UHPFRC with high flowability allows the production of the final structure. Extensive research was done before production of footbridge. Two versions of large scale mock-ups were casted and tested. According to the complexity of whole experiment a casting technology and production of formwork were tested and optimized many times. Experimental reached data were compared with extensive numerical analysis and the final design of structure and UHPFRC matrix were optimized in many details.

Abstract: The article is focused on the design of spatially curved cable - supported footbridges, which represent a simple and elegant solution for bridging longer spans. It can be used independently or in a combination with other structural arrangements, e.g. with the arch structures.To verify the behavior of the structure, a several testing models were created. At first only simple, plan – straight models were created so the results could be checked by manual calculations. Latter, the more complex, curved models were tested. All models were designed and analyzed with the Ansys software using geometrically nonlinear calculations. The analysis consisted in the searching for ideal geometry of the supporting cable, cross section geometry of the bridge deck and other parameters, which are necessary to find a correct initial state of the structure. The main criterion for finding the initial state was a demand of minimal deformations in the strut - supporting nodes, which leads to the minimal redistribution of the internal forces during the design lifetime. The result of the paper is a detailed analysis of the construction’s behavior. The main emphasis is on methodology of search for the initial state. Further, the buckling analysis of the struts and cable were performed and it’s resistance to buckling was determined using various live load configurations.

Abstract: Article deals with design of footbridge made from ultra high performance concrete (UHPC). UHPC is relatively new type of cementitious material with high compressive strength and high durability. For reliable design of construction from this material an extensive experimental research and verification of material properties are needed. Skanska and Pontex company with cooperation with Klokner institute developed matrix of UHPC used for footbridge construction. Material properties were verified during whole developing and producing process. Footbridge was casted in precast plant Skanska – Steti in December 2014. It was installed over Opatovický canal in October 2015. Contribution describes design, production and installation of footbridge. Material properties of used UHPC are also included.

Abstract: The paper deals with a dynamic response of footbridge structure which is loaded by a movement of pedestrians. Interaction between crowd and footbridge structure is a complex problem. It is important to take into account load generated by the movement of pedestrians during the computation, but also change of load influenced by a response of the structure. It means practically that the response of the structure has influence on the movement of pedestrians. Computation of the response has to be performed in several steps. The first step is backward modification of load represented by the crowd movement. Next step is recalculation of the structure with newly compiled load. This approach can bring near the real behaviour of the structure which is exposed by the continuous movement of pedestrians..

Abstract: Arch footbridges are one of the fields that authors of this paper deal with. Amid the studied variants were also structures with lower deck suspended on two arches of various geometric arrangements. The analysis was, among others, focused on the advantage of the application of non-rigid segmental deck with respect to final behaviour and rheological effects. These effects were considered both on case studies and real structure in Salem, Oregon, currently being erected.

Abstract: The thermal displacement of a large scale footbridge is investigated in this study through numerical simulation. With appropriate assumption, the temperature field of the footbridge is simplified and divided into several components. Fine finite element models are constructed for the deck plate, bridge section, and bridge tower to calculate the structural thermal effects. The made observations indicate that the thermal deformation of the bridge tower is much larger than that of the deck due to the cable sag under temperature increase.