基于薄板单元的水泥混凝土路面荷载应力分析

将刚性、半刚性基层上水泥混凝土路面结构简化为弹性地基上不等平面尺寸双层结构模型,在轴(轮)载作用下,采用薄板单元,讨论了模型网格划分和计算精度的关系.研究了移动轴载作用下路面结构最大荷载应力大小和位置的变化规律.分析了基层超宽对面层和基层自身最大荷载应力的影响,基层超宽降低了面层的荷载应力,幅度为0～33%;但基层自身荷载应力明显增大.比较了采用薄板单元及实体单元时面层和基层最大荷载应力的差异,当面、基层厚度增大时,采用薄板单元得到的面层荷载应力偏大0～20%;而基层荷载应力偏小2%～30%.给出了标准轴载作用于纵边中部荷位的荷载应力修正系数.

Loading Stress Analysis of Double-layered Cement Concrete Pavement Structure Using Thin Shell Element

The cement concrete pavement on rigid or semi-rigid base is hereof simplified as a model of double-layered structure with unequal planar dimensions resting on an elastic foundation, under axle (tire) load, by using thin shell element the relationship between element meshing size and result accuracy is discussed, the locations and magnitudes of the maximum loading stresses in pavement structure under moving axle load along longitudinal edge are thoroughly studied, the effects of base extension on the maximum loading stresses in pavement and base are also analyzed, the results showed that with increase of the base extended amount the maximum loading stress in pavement will drop 0~33%; whereas the maximum stress in base will increase remarkably. Furthermore, the difference of the maximum loading stresses in pavement and base by using shell element and solid element is compared, when the thicknesses of pavement exceeding a limited value, the maximum stress in pavement based upon shell element is 0~20% larger than that of solid element; but in base is 2~30% smaller; in the end, the modified coefficient for the maximum stresses in pavement and base by using shell element is provided.