Conceptual design and manufacture of ecoduct using fibre reinforced polymer composite materials

Abstract

ABSTRACT The growth of transport infrastructure has led to the fragmentation of the natural habitat of many animal species in Sweden. Ecoducts, large bridges with a layer of soil and vegetation on top of it, provide a safe crossing of highways for animals. In this thesis, the design of an ecoduct made of fibre reinforced polymer composites (FRP) was developed. The aim was to develop a typical solution for the ecoduct that could be further used in the design of ecoducts made of FRP composites in Sweden. Initially, the conditions and requirements for ecoducts in Sweden were studied by literature review and interview with an expert in the field. It was concluded that motorways and highways contribute most to the fragmentation effect. A minimum width for ecoducts of 30 m and a recommendation of tree vegetation on the edges of the ecoduct was identified. The possibilities and advantages of FRP as a building material for ecoducts were investigated. 19 preliminary design solutions were developed in order to determine the most suitable ecoduct structural system with an emphasis on the bearing capacity of the structural elements of different cross-sections. The types and performance of FRP composites under static load were evaluated to select the most efficient composite materials for the design of ecoducts. Existing production possibilities were considered for the further prospects of manufacturing of the bridge elements. The final proposed design includes a detailed design of the bridge members and provides several possible solutions for the structural joints. Finite element analyses were performed to optimize the final design decision. The deflection under the static load, maximum allowable stresses and buckling behavior of the bridge sections were investigated. Humidity, temperature and creep effects on the FRP material were taken into consideration. The proposed design is an effective solution in terms of the carrying capacity of the developed section and the material use.