龙卷风环境下连续梁顶推施工阶段导梁极值响应分析

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关键词：连续梁；顶推施工；参数敏感性分析；极值分析；龙卷风中图法分类号： 文献标识码：A 文章编号：1000-2324（2025）03-0536-11

Abstract：ThesoutheasterncoastofChina frequentlyexperiencestormadoes，posingrisks tobridgeconstructionprojects. However，studies onthesafetyof temporary bridgestructures in tornadoconditionsare limited.This paper examines the maximum cantilever phase of the launching nose during the incremental launching of a coastal continuous bridge.A 3D finite element modelofthe temporary structural system was built，andcomputationalfluid dynamics （CFD）analysis was usedto determinethe aerodynamic forces onthe main girderandlaunching noseunderlateraland vertical winds.The study then explored how the maximum deformation of the launching nose varied with the tornado's attack angle ψ ，maximum vortex core radius Rmax， and maximum tangential wind speed Vmax .A response surface model was created to assess the sensitivityof the nose'sdeformation tothese tornadocharacteristicvariables.BasedonaType II extreme value tornado wind speed distribution model，the virtual process method （VPM） was appied toevaluate the probabilityof maximum displacement.ResultsshowthatfortormadoesbelowEF3，thelaunching nose'slateraldisplacementandrotationintheRotX direction are most sensitive to Vmax ，followed by ψ and Rmax .At ψ=10∘ and Rmax=40m ，the 90th percentile extreme displacements are 0.40m （lateral）， 0.28m （vertical）， and 5.2×10-3rad （RotX）. This paper examines the extreme response of temporary bridgestructures during construction frombothdeterministicandstochasticdynamicperspectives，providing guidance forreliability-based bridgewind-resistantdesignandemergencyplanning forbridgeconstructionintorado-prone areas.Aditionally，theextremevaluesensitivityanalysisprovidesatheoreticalbasisforimprovingtheefficiencyof dynamicreliabilitynumericalanalyses for bridgesunder tornadoconditions.

Keywords：Continuousbridge;incrementallaunchingconstruction;parametersensitivityanalysis;extremeanalysis;torado

近年来，我国东南沿海和东北部地区频遭龙卷风侵袭。（剩余12753字）