Prediction of long-term extreme load effects due to wave and wind actions for cable-supported bridges with floating pylons

Abstract The characteristic values of the extreme environmental load effects should correspond to a specified annual probability of exceedance. These load effects can be calculated using short-term or long-term methods. The full long-term method is considered the most accurate approach, but it requires tremendous computational effort for complicated structures, especially when nonlinearities must be considered. In a case study of the dynamic behavior of a three-span suspension bridge with two floating pylons, these nonlinearities are found to have a significant effect on the extreme values of some of the load effects. It is thus recommended to determine these responses in the time domain. However, time-domain simulations can be very time consuming even by using simplified approaches such as the environmental contour method (ECM) and the inverse first-order reliability method (IFORM). Therefore, this paper introduces a computationally efficient approach utilizing the ECM and the IFORM to determine long-term extreme values based on responses from combined frequency- and time-domain simulations.

[1]  Stephen J. Wright,et al.  Numerical Optimization , 2018, Fundamental Statistical Inference.

[2]  S. Haver,et al.  Joint Distribution For Wind And Waves In the Northern North Sea , 2002 .

[3]  Hong Li,et al.  An inverse reliability method and its application , 1998 .

[4]  R. Rackwitz,et al.  Structural reliability under combined random load sequences , 1978 .

[5]  Luis Volnei Sudati Sagrilo,et al.  On the long-term response of marine structures , 2011 .

[6]  Oleg Gaidai,et al.  Estimation of extreme values from sampled time series , 2009 .

[7]  Ahsan Kareem,et al.  Advances in modeling of Aerodynamic forces on bridge decks , 2002 .

[8]  Bernt J. Leira,et al.  Long-Term Extreme Response Analysis of Marine Structures Using Inverse SORM , 2017 .

[9]  A. Kareem,et al.  AERODYNAMIC COUPLING EFFECTS ON FLUTTER AND BUFFETING OF BRIDGES , 2000 .

[10]  Torgeir Moan,et al.  Hybrid frequency-time domain models for dynamic response analysis of marine structures , 2008 .

[11]  Torgeir Moan,et al.  Time Domain Modelling of Frequency Dependent Wind and Wave Forces on a Three-Span Suspension Bridge With Two Floating Pylons Using State Space Models , 2017 .

[12]  A. Kareem,et al.  TIME DOMAIN FLUTTER AND BUFFETING RESPONSE ANALYSIS OF BRIDGES , 1999 .

[13]  Ove Ditlevsen,et al.  Principle of Normal Tail Approximation , 1981 .

[14]  J. N. Sharma,et al.  Second-Order Directional Seas and Associated Wave Forces , 1981 .

[15]  Einar N. Strømmen.  Theory of Bridge Aerodynamics , 2010 .

[16]  Yan-Gang Zhao,et al.  A general procedure for first/second-order reliabilitymethod (FORM/SORM) , 1999 .

[17]  Ragnar Sigbjörnsson,et al.  Finite element formulation of the self-excited forces for time-domain assessment of wind-induced dynamic response and flutter stability limit of cable-supported bridges , 2012 .

[18]  Robert H. Scanlan,et al.  AIR FOIL AND BRIDGE DECK FLUTTER DERIVATIVES , 1971 .

[19]  Ragnar Sigbjörnsson,et al.  Simplified prediction of wind-induced response and stability limit of slender long-span suspension bridges, based on modified quasi-steady theory: A case study , 2010 .

[20]  Lance Manuel,et al.  Design Loads for Wind Turbines Using the Environmental Contour Method , 2006 .

[21]  Torgeir Moan,et al.  Joint Distribution of Environmental Condition at Five European Offshore Sites for Design of Combined Wind and Wave Energy Devices , 2015 .

[22]  Shun Wei Gong.  Dynamic Response of Suspension Bridge with Floating Towers , 2016 .

[23]  Sverre Haver,et al.  Environmental Contour Lines for Design Purposes: Why and When? , 2004 .

[24]  S. Haver,et al.  Environmental Contour Lines: A Method for Estimating Long Term Extremes by a Short Term Analysis , 2008 .

[25]  Torgeir Moan,et al.  Stochastic Dynamics of Marine Structures: Index , 2012 .

[26]  Torgeir Moan,et al.  Modified environmental contour method for predicting long-term extreme responses of bottom-fixed offshore wind turbines , 2016 .

[27]  Torgeir Moan,et al.  Prediction of long-term extreme load effects due to wind for cable-supported bridges using time-domain simulations , 2017 .

[28]  Torgeir Moan,et al.  Modified environmental contour method to determine the long-term extreme responses of a semi-submersible wind turbine , 2017 .

[29]  Torgeir Moan,et al.  Time domain simulations of wind- and wave-induced load effects on a three-span suspension bridge with two floating pylons , 2018 .

[30]  M. Rosenblatt.  Remarks on a Multivariate Transformation , 1952 .

[31]  Armen Der Kiureghian,et al.  Inverse Reliability Problem , 1994 .

[32]  Ahsan Kareem,et al.  Aeroelastic Analysis of Bridges under Multicorrelated Winds: Integrated State-Space Approach , 2001 .

[33]  G. Kleiven,et al.  Met-Ocean Contour Lines For Design; Correction For Omitted Variability In the Response Process , 2004 .

[34]  Odd M. Faltinsen,et al.  Sea loads on ships and offshore structures , 1990 .

[35]  Ahsan Kareem,et al.  Multimode coupled flutter and buffeting analysis of long span bridges , 2001 .