动荷载作用下沥青路面的表面裂缝扩展研究

发布时间：2018-10-19 14:26

【摘要】：【目的】研究沥青路面表面裂缝在动荷载作用下的扩展行为,分析完整沥青路面结构和含表面裂缝结构的负荷响应,探讨应力强度因子K2随着荷载变化的规律,以及表面裂缝在扩展过程中K2的敏感性,为公路工程中路面结构抗裂设计提供一定理论依据。【方法】应用有限元软件ABAQUS建立沥青路面表面裂缝结构模型,基于动力学理论对交通荷载作用下沥青路面结构进行数值计算。【结果】动荷载作用下,完整沥青路面的表面弯沉较静态荷载有所减小,随着裂缝扩展深度的增大,弯沉值会逐渐增大;动应力强度因子K2的变化曲线较荷载变化曲线具有一定的滞后性,且最大值大于静态荷载下K2的值;表面裂缝向下扩展过程中,K2在扩展前期增长速率较快,扩展至面板厚度一半后,K2的增长速率逐渐放缓;减小面层模量、增大基层模量和厚度,能够较好地抑制表面裂缝的扩展,其余参数则影响较小;K2随着行车荷载的增大呈线性增长趋势,裂缝扩展越深K2增加越显著。【结论】延长含表面裂缝的沥青路面结构的使用寿命,较好的方法是减小面层动态模量,适当增大基层的动态模量以及增大基层的厚度。
[Abstract]:[objective] to study the spreading behavior of asphalt pavement surface crack under dynamic load, analyze the load response of the intact asphalt pavement structure and the structure with surface crack, and discuss the law of stress intensity factor K2 changing with the load. The sensitivity of K2 in the process of surface crack propagation provides a certain theoretical basis for the anti-crack design of pavement structure in highway engineering. [methods] the surface crack structure model of asphalt pavement is established by using finite element software ABAQUS. Based on the dynamic theory, the asphalt pavement structure under traffic load is numerically calculated. [results] under dynamic load, the surface deflection of the intact asphalt pavement is smaller than that of the static load, and with the increase of crack propagation depth, The deflection value increases gradually, the dynamic stress intensity factor K2 curve has some hysteresis compared with the load change curve, and the maximum value is larger than that under static load, and the growth rate of K2 is faster during the downward propagation of surface crack. After extending to half of the thickness of the face plate, the growth rate of K2 gradually slows down, and the surface modulus decreases, and the base modulus and thickness increase, which can better restrain the growth of surface cracks. The other parameters have little effect, K _ 2 increases linearly with the increase of driving load, and the deeper the crack is, the more K _ 2 increases. [conclusion] prolonging the service life of asphalt pavement structure with surface cracks, The better method is to reduce the dynamic modulus of the surface layer, increase the dynamic modulus of the base and increase the thickness of the base.
【作者单位】：南京林业大学土木工程学院;苏州建设交通高等职业技术学校;
【基金】：江苏省普通高校学术学位研究生科研创新计划(KYLX_0884)
【分类号】：U416.217;U418.6

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