沿河公路平行悬空混凝土路面板断裂力学模型  

Fracture Mechanics Model of Parallel Dangling Concrete Pavement Slab Along River

作　　者：陈洪凯[1] 周福川 唐红梅[1] 

机构地区：[1]重庆交通大学岩土工程研究所,重庆400074 [2]重庆市渝西水利电力建筑勘测设计院,重庆402160

出　　处：《中国公路学报》2016年第3期25-34,共10页China Journal of Highway and Transport

基　　金：2013年重庆高校创新团队建设计划项目(KJTD201305);重庆市"两江学者"计划专项资金项目(201309);交通运输部西部交通建设科技项目(2009 318 221 035)

摘　　要：为了研究悬空路面板断裂机制,按照Winkler弹性地基假设,借鉴Westergaard求解非悬空无限大板应力解的思路,将平行悬空路面等效为非悬空路面板,按照特殊的边界条件进行处理,得到了平行悬空路面板应力场解析表达式。结合断裂力学的观点,选取三维断裂模型设置表生裂纹,分析受路面板悬空部分自重和车辆荷载作用下的极限承载力。通过工程实例,得出了悬空比例R与极限承载力之间的关系,同时对该等效方法的适用范围进行了讨论。结果表明:当悬空比例R=0.4时,极限承载力为50.3kN,在标准轴载作用下,50kN的车辆荷载就可能使得悬空路面板发生突然的脆性断裂破坏,导致安全事故发生;当0<R<0.5时,悬空路面板发生局部断裂破坏,可以按照所提出的等效方法求解极限承载力;当R≥0.5时,悬空路面板未达到极限承载力即发生整体性倾覆破坏,该求解方法将不再适用。In order to investigate the fracture mechanism of the dangling concrete pavement slab,on the basis of Winkler＇s elastic foundation hypothesis,referring the thought of Westergaard in solving the complete infinite slab＇s stress field,the parallel dangling pavement slab was equivalent to the complete pavement slab.Special boundary conditions were adopted to obtain the analytical expression of the parallel dangling pavement slab field.Combining the view of fracture mechanics,the surface crack was set on the selected 3Dfracture model,and the ultimate bearing capacity under dead weight of the dangling pavement slab and vehicle loads was analyzed.According to the engineering example,the relationship between dangling ratio Rand the ultimate bearing capacity was obtained.The application scope of the equivalent method was discussed.The results show that when the dangling ratio Ris equal to 0.4,the ultimate bearing capacity is50.3kN,which means that under the effect of the standard axle load,the immediate brittlefracture of the dangling pavement slab will take place under 50 kN vehicle load which results in accident.While the dangling ratio Ris between 0and 0.5,the local fracture damage will occur,then the equivalent solution of the ultimate bearing capacity provided by this paper can be utilized;while the dangling ratio Ris no less than 0.5,the ultimate bearing capacity will never achieve the ultimate bearing capacity and the integrity overturn failure will occur and the equivalent method in this paper cannot be used.

关 键 词：道路工程 悬空路面 断裂力学 极限承载力 应力场 

分 类 号：U416.216[交通运输工程—道路与铁道工程]