裴必達 李立峰 邵旭東 王連華 曾研

摘? ?要：鋼-UHPC輕型組合橋面板是一種由正交異性橋面與密集配筋的UHPC薄層通過剪力釘連接而成的新型橋面結(jié)構(gòu).為研究UHPC層對鋼-UHPC輕型組合橋面結(jié)構(gòu)性能的影響，以楓溪大橋為工程背景，研究正交異性鋼橋面常見疲勞細節(jié)在鋪設(shè)UHPC層前、后的應(yīng)力幅變化.首先通過整體有限元模型確定測點位置以及加載范圍，然后根據(jù)加載方案分別在鋪設(shè)UHPC層前后采用三軸加載車進行低速加載試驗，同時采集并整理正交異性鋼橋面常見疲勞細節(jié)應(yīng)力響應(yīng)試驗數(shù)據(jù)，最后建立了節(jié)段有限元模型并與實測結(jié)果進行對比分析.試驗結(jié)果表明：鋪設(shè)UHPC層后，常見疲勞細節(jié)應(yīng)力響應(yīng)均有明顯降低，其中面板上的細節(jié)（縱肋-面板焊縫、面板對接焊縫、面板-橫隔板-縱肋交叉焊縫面板位置）應(yīng)力幅降幅比例最大，高達75%～90%;其次為縱肋上疲勞細節(jié)（縱肋底部對接焊縫、縱肋-橫隔板焊縫焊縫端部位置、面板-橫隔板-縱肋交叉焊縫縱肋位置）應(yīng)力降幅約為65%～80%;最后為橫隔板上疲勞細節(jié)（橫隔板弧形切口、橫隔板弧形切口起點位置、面板-橫隔板-縱肋交叉焊縫橫隔板位置）應(yīng)力降幅約為20%～50%.同時，隨疲勞細節(jié)與頂面距離的減小，UHPC層對細節(jié)應(yīng)力降幅的貢獻明顯增大.有限元模型結(jié)果與實測結(jié)果吻合較好，也得出了相似的規(guī)律.本文實測結(jié)果為推廣鋼-UHPC輕型組合橋面的應(yīng)用提供了最直接的數(shù)據(jù)參考.

關(guān)鍵詞：橋梁工程;輕型組合橋面板;現(xiàn)場試驗;疲勞細節(jié);應(yīng)力幅;UHPC層

中圖分類號：U443.33? ? ? ? ? ? ? ? ? ? ? ? 文獻標志碼：A

文章編號：1674—2974（2019）01—0076—09

Abstract： The steel-UHPC lightweight composite deck is a novel bridge deck pattern that consists of an orthotropic steel deck（OSD） and a thin ultra-high performance concrete（UHPC） layer. In order to reveal the effect of UHPC layer on the performance of the OSD， field measurement was performed for Fengxi Bridge to evaluate the stress ranges in the typical detail categories of the OSD with/without UHPC layer， respectively. Before the field measurement was conducted， the global finite element model of Fengxi Bridge was developed to determine the instrumented sections. Then， a triaxial loading vehicle， according to the loading scheme，was arranged to run on the bridge deck with/without UHPC layer at a low speed， respectively. The field measurement data of the typical detail categories were collected and sorted. Finally， a local finite element model of Fengxi Bridge was built to compare with the field measured results. The field measurements show that the stress response of the typical detail categories are significantly reduced after installment of UHPC layer. For the detail categories related to the steel deck（i.e.， rib-to-deck weld， deck splices， and deck of rib-to-deck at diaphragm joint），the stress range decreased by about 75% ～ 90%;for the detail categories related to the trapezoidal rib（i.e.， rib splices， weld end of rib-to-diaphragm joint， and rib of rib-to-deck at diaphragm joint），the stress range decreased by about 65% to 80%; for the detail categories related to the diaphragms（i.e.，cut-out on diaphragm， diaphragm base metal at cut-out transition， and diaphragm of rib-to-deck at diaphragm joint），the stress range decreased by about 20% to 50%. Meanwhile， with the decrease of the distance from detail categories to top surface， the contribution of UHPC layer to the stress reduction of the detail categories was significantly increased. The results of the local finite element model agreed well with the measured results， and the similar rules were obtained. The field measured results of this paper provide the reference data for the application of steel-UHPC lightweight composite bridge deck.