龍卷風(fēng)環(huán)境下連續(xù)梁頂推施工階段導(dǎo)梁極值響應(yīng)分析

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關(guān)鍵詞：連續(xù)梁；頂推施工；參數(shù)敏感性分析；極值分析；龍卷風(fēng)中圖法分類號： 文獻(xiàn)標(biāo)識碼：A 文章編號：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

近年來，我國東南沿海和東北部地區(qū)頻遭龍卷風(fēng)侵襲。（剩余12753字）