目前钢桥面板以其容重小、强度较高、适应装配化生产而得到了广泛的应用.铺筑于钢桥面板之上的沥青铺装可有效分散轮载,并起到强化钢桥面板刚度的作用,可有效减缓顶板与纵肋构造细节疲劳损伤速率.但沥青铺装的荷载分散效应和刚度强化作用易受温度和荷载频率的影响,为探究铺装特性对顶板与纵肋疲劳损伤的耦合影响机制,基于沥青铺装材料动态应力-应变关系,分析并量化了沥青铺装层温度与动力特性对顶板与纵肋构造细节疲劳损伤的影响效应.在此基础上,结合实桥车流数据建立了日内每小时随机车流荷载模型,量化了沥青铺装层温度与动载效应对关注细节疲劳损伤特性的耦合影响.研究结果表明,在其他边界条件相同时,夏季钢桥面板疲劳损伤约为冬季钢桥面板疲劳损伤的 3.7 倍;传统不考虑铺装特性的钢桥面板寿命评估偏于不安全,考虑铺装的温度效应和动载效应后,钢桥面板的疲劳寿命从约 54.2 a 降低至约 42.7 a,降低幅度达21.2%.
Coupling Effect Mechanism of Pavement Characteristics on Fatigue Damage of Orthotropic Steel Decks
Orthotropic steel decks have been widely used in steel bridges due to their small volume weigh,high strength and good applicability of assembly fabrication.The asphalt pavement laying on the orthotropic steel deck can effectively disperse the vehicle wheel loads,and enhance the stiffness of orthotropic steel decks,and release fatigue damage of deck-to-rib welded joints of orthotropic steel decks.However,the effects of asphalt pavement on orthotropic steel decks were affected by the temperature and loading frequen-cy.To determine the coupling effect mechanisms of pavement characteristics,based on the dynamic stress-strain relations,the effects of temperature and dynamic properties on the fatigue damage of deck-to-rib wel-ded joints were firstly analyzed and quantified.The hourly random traffic flow model in a day was estab-lished by using the real traffic flow data,then the coupling effects of temperature and dynamic loads on the fatigue damage characteristics of asphalt pavement layers were quantified.The results indicated that when other boundary conditions were the same,the fatigue damage of deck-to-rib welded joints in summer was a-bout 3.7 times as the fatigue damage in winter.The fatigue life assessment without consideration of pave-ment properties was underestimated.The fatigue life would reduce from 54 years to 47 year after consider-ing the pavement properties.
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万方数据
