混凝土路面传力杆疲劳松动行为的试验研究与数值模拟  

Experimental Study and Numerical Simulation of Fatigue Looseness Behavior of Dowel Bars in Concrete Pavement

作　　者：严圆 李洛克[2] 周亦唐[2] 保亮 YAN Yuan1, LI Luo-ke2, ZHOU Yi-tang2, BAO Liang2(1. Yunnan Provincial Highway Science and Technology Research Institute, Kunming Yunnan 650000, China; 2. Kunming University of Science and Technology, Kunming Yunnan 650500, Chin)

机构地区：[1]云南省公路科学技术研究院,云南昆明650000 [2]昆明理工大学,云南昆明650500

出　　处：《公路交通科技》2018年第5期8-15,共8页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(50808058);云南省人才培养基金项目(KKSY201306093)

摘　　要：针对水泥混凝土路面传力杆的疲劳失效问题,从传力杆与混凝土接触面力学性能退化的角度入手,研究了传力杆疲劳失效现象的产生机理与扩展规律。首先,建立了考虑传力杆与混凝土、面层与基层接触面力学行为的水泥混凝土路面三维有限元模型,研究了多种车辆轴载作用于板边时传力杆装置的力学特性;其次,开发了传力杆与混凝土接触面力学性能试验系统,设计了传力杆试件的拟静力加速加载试验,模拟了传力杆疲劳松动的形成过程;再次,根据试验现象建立了含弥散裂纹体的缩缝子结构有限元模型,应用扩展有限元法模拟了传力杆的疲劳松动行为;最后,提出了基于数值分析技术的水泥混凝土路面缩缝临界车辆轴载计算方法。研究发现:轮胎与路面接触位置下方传力杆附近应力集中区域是荷载传递过程中缩缝结构的最不利位置;重载车辆长期作用导致传力杆周边混凝土材料长期处于高接触应力加卸载状态,由此引发的龟裂与剥落最终将造成传力杆疲劳松动量的不断增加;应用数值分析技术可有效地反演路面缩缝结构的临界车辆轴载,防止传力杆周边混凝土内出现损伤累积,避免传力杆发生疲劳松动。研究成果有助于更精确地评估水泥混凝土路面传力杆装置的工作状态,了解传力杆在交通荷载与环境等因素长期作用下的失效过程,科学地预测传力杆装置的疲劳寿命,快速地进行设计方案对比。Focusing on the fatigue failure of dowal bar in cement concrete pavement（ CCP）,the mechanism and propagation rule of the fatigue failure are studied in respect of the mechanical performance degradation of the contact interface between dowel bar and concrete. First,the 3 D FE model of CCP is established considering the mechanical behaviors of dowel bar to concrete and surface to base,and the mechanical characteristics of dowel bar system under various vehicle axle loadings act on the edge of plate are studied.Second,the testing system of contact interface between dowel bar and concrete is developed,the pseudostatic accelerate fatigue loading test is designed to simulate the loosening process of dowel bar. Then,the shrink joint substructure FE model which contains the smeared cracks is established based on the test,and the fatigue looseness behavior is simulated by extended FE method. Finally,the calculation method of critical vehicle axel load of shrink joint of CCP is presented. The result shows that（ 1） the unfavorable position ofthe shrink joint in load transfer process is the stress concentration region located around the dowel bar under wheel loading;（ 2） the long term action of heavy-duty vehicles caused the high contact stress loading/unloading state of the concrete around the dowel bar and the cracking and spalling of concrete,which will eventually lead to the increasing fatigue looseness of the dowel bar;（ 3） application of numerical analysis technique can effectively invert the critical vehicle axle load of the pavement shrinkage structure,prevent the accumulation of damage in the concrete around the dowel bar and avoid the fatigue loosening of the dowel bar. This study helps more accurate evaluation on the working condition of dowel bars in CCP,understand the failure process of the dowel bar under long-term effects of traffic load and environment,helps more scientific prediction on the fatigue life of dowel bar,and helps more rapid comparisons for design schemes.

关 键 词：道路工程 疲劳失效行为 子结构试验方法 传力杆松动 声发射 扩展有限元法 弥散裂纹 

分 类 号：U416.216[交通运输工程—道路与铁道工程] TU317[建筑科学—结构工程]