Abstract
Reliable design codes are of great importance when constructing new civil engineering concepts such as floating bridges. Previously only a scarce number of floating bridges have been built in rough wave conditions and only limited knowledge of the extreme environmental conditions and the associated extreme response exists. To form a better design basis an increased understanding of the sensitivity in the structural response towards changes in short-crested sea parameters is needed. Furthermore, acquiring the necessary accuracy in simulated extreme response is often a computationally expensive endeavour and the number of simulations needed is often based on experience. The present study investigates the wave-induced short-term extreme response of a simplified end-anchored floating bridge concept for several wave environments with a return period of 100 years. The study includes convergence of the coefficient of variation for the extreme response for different realization lengths as well as number of realizations. The sensitivity in the structural response towards different main wave directions and spreading exponents is investigated and includes both transverse and vertical displacement response spectra and extreme Von Mises stress in the bridge girder cross-section. The extreme response is based on an accuracy of 2% in the coefficient of variation equivalent to 40 3-h realizations and a low sensitivity in the response is found for natural occurring spreading exponents and for main wave directions within 15° from beam sea.
Highlights
The Norwegian Public Roads Administration (NPRA) is currently undertaking a large infrastructure project involving floating bridge structures over their wide and deep fjords
Stochastic wave loading processes and their application in stochastic response of floating bridges has been a research topic since the late 1970s and the structural response of a short curved floating bridge with continuous pontoons was thoroughly investigated in the late 1970s and the 1980s [1,2,3,4,5,6] when construction of the Bergsøysund Bridge and the Nordhordland Bridge was under way
Hutchison [8] showed that a logical consistency existed between the two principal methods existing at the time for describing the dynamic response from short-crested waves, i.e. superposition of long-crested waves and an explicit representation of the short-crested behaviour of the incident wave field such as the one described by Sigbjörnsson [2]
Summary
The Norwegian Public Roads Administration (NPRA) is currently undertaking a large infrastructure project involving floating bridge structures over their wide and deep fjords. Stochastic wave loading processes and their application in stochastic response of floating bridges has been a research topic since the late 1970s and the structural response of a short (less than 1500 m) curved floating bridge with continuous pontoons was thoroughly investigated in the late 1970s and the 1980s [1,2,3,4,5,6] when construction of the Bergsøysund Bridge and the Nordhordland Bridge was under way The studies included both time domain and frequency domain analyses and included regular waves, irregular long-crested waves and short-crested waves. Langen and Leira [4,5,6] carried out several studies on the probabilistic design of the short floating bridge structure focusing on the bending moments and pre-tension force in the bridge
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
