Livsløpsvurdering og dimensjonering av stålog limtrebue i en nettverksbuebru

Abstract

This master thesis focuses on the design and life cycle assessment (LCA) of a network arch bridge. The arch is designed and compared by using two different materials, steel and gluelam. This study is carried out on the behalf of Statens vegvesen, Region øst, and serves as the graduate thesis for master degree in Civil Engineering at the University of Agder. The network arch bridge is part of E16 and is located at Oppstadåa. The bridge carries four lanes, which results in a 21 meters wide deck. The span of the bridge is 120 meters. Three different network arch bridges alternatives have been designed in this thesis. The original network arch bridge alternative, with steel arches and wind bracing, is designed based on the preliminary project given by Statens vegvesen. This design is further on optimized to use less construction material. The third design uses gluelam in the arches and wind bracing. The designs are verified using eurocodes and Statens vegvesen handbooks. This thesis also includes a LCA study to compare the three designs on environmental impacts. The data is obtained by EPD’s and the ecoinvent database implemented in the computer program used, Simapro. Excel is used to interpret the results for the comparison. The optimized network arch bridge alternative reduces the construction steel amount by 14,4%. It is confirmed possible to construct the network arch bridge alternative using gluelam, with the given limitations in this thesis. The LCA results concludes that the gluelam network arch bridge alternative is preferable regarding the environmental impacts compared to the steel alternatives.