Numerical Method of Flexible Pavement considering Moisture and Stress Sensitivity of Subgrade Soils
Numerical Method of Flexible Pavement considering Moisture and Stress Sensitivity of Subgrade Soils
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考虑路基土湿度和应力敏感性的柔性路面数值方法
DOI：
10.1155/2019/7091210
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发表时间：
2019-05
影响因子：
1.8
通讯作者：
Junhui Peng
中科院分区：
文献类型：
--
作者：
Jue Li;Jianlong Zheng;Yongsheng Yao;Junhui Zhang;Junhui Peng
路基结构的缺陷导致沥青路面病害的发生，缩短了柔性路面的使用寿命。然而，路基土的回弹模量（Mr）是很难直接评估，因为路基被隐藏和覆盖的粒料或沥青层。本研究旨在建立一种考虑路基土应力敏感性和湿度变化的柔性路面动力特性数值预测方法。首先，在半正弦荷载作用下，对柔性路面进行了二维有限元模拟。提出了一种考虑吸力和八面体剪应力的路基土本构模型。用3种土样的室内三轴试验数据进行了验证。利用ABAQUS软件中的用户自定义材料子程序（UMAT）对模型进行编程。最后，通过水池模型验证了有限元模型的有效性。最后，通过拉应力和竖向压应变分析，研究了含水率对路面结构动力响应的影响。结果表明，有限元模型的表面弯沉与实际路面结构的表面弯沉相似，R2为98.44%。所开发的UMAT程序是可靠的，因为在有限元模型中的MR的分布受到路基土的应力和水分条件的影响。当含水量增加63%时，路基土的平均Mr降低了18.7%。同时，路基土的刚度软化使路基顶部的竖向压应变和表层底部的拉应力增大。值得注意的是，该模型可用于分析路基和表层的疲劳开裂在未来。
Weaknesses of the subgrade structure induce the asphalt surface diseases and shorten the service life of flexible pavement. However, the resilient modulus (Mr) of subgrade soils is difficult to be evaluated directly since the subgrade is hidden and covered by the granular or asphalt layer. This study aimed to establish a numerical approach to predict the dynamic behavior of flexible pavements considering the stress sensitivity and moisture variation of subgrade soils. Firstly, 2D FEM simulations of flexible pavements were performed with half-sine loadings. A constitutive model of subgrade soils was proposed to incorporate soil suction and octahedral shear stress. It was validated using the laboratory triaxial test data of 3 selected soils. Then, the developed model was programmed by the user-defined material subroutine (UMAT) in the software ABAQUS. Subsequently, the validity of FEM model was verified by the laboratory tank model. Finally, the effect of moisture contents on the dynamic response of pavement structures was studied by tensile stress and vertical compressive strain. Results show that the surface deflection of the FEM model is similar to that of the actual pavement structure with the R2 of 98.44%. The developed UMAT program is reliable since the distribution of Mr in the FEM model is influenced by the stress and moisture condition of subgrade soils. When the moisture content is increased by 63%, the average Mr of subgrade soils is decreased by 18.7%. Meanwhile, the stiffness softening of subgrade soils increases vertical compressive strain at the top of the subgrade and the tensile stress at the bottom of the surface layer. It is interesting that the developed model can be applied to analyze the fatigue cracking of both subgrade and surface layers in the future.
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影响因子：
2.4
作者：
P. Ekins
通讯作者：
P. Ekins
影响因子：
1.9
作者：
F. Blattner
通讯作者：
F. Blattner
DOI：
10.1061/(asce)te.1943-5436.0000727
发表时间：
2015
期刊：
Journal of Transportation Engineering-asce
影响因子：
--
作者：
Changjun Zhou;Baoshan Huang;E. Drumm;X. Shu;Qiao Dong;S. Udeh
通讯作者：
Changjun Zhou;Baoshan Huang;E. Drumm;X. Shu;Qiao Dong;S. Udeh
影响因子：
1.6
作者：
Vicki D Crinis
通讯作者：
Vicki D Crinis
影响因子：
0.2
作者：
R. Eglash
通讯作者：
R. Eglash