交通循环荷载作用下粉土路基的动态响应分析

Dynamic Analysis of Silt Subgrade under Traffic Loads

摘要:

粉土是一种介于粘土和砂土之间具有特殊工程性质的土类。为了研究粉土路基在长期交通循环荷载作用下的动态响应过程，利用有限元动态分析方法，采用一种能够描述粉土累积变形发展过程的循环本构模型，对安徽淮北地区粉土路基在长期交通荷载作用下的动态响应过程进行了数值模拟分析。分析结果表明粉土路基在长期循环加载过程中会产生显著的累积沉降变形。车辆荷载传递至路面以下的附加应力，在经过路面层以后首先发生较大程度的衰减，然后通过1.5m厚的路基层，附加应力会进一步衰减至最大附加应力的10%左右。因此，1.5m厚的路基层可以考虑作为粉土路基承受车辆荷载的主要工作区。

Abstract:

Silt has special engineering characteristics between clay and sand. To study the dynamic response of silt subgrade under long-term traffic loads, a dynamic FEM analysis based on a constitutive model that can describe the developing process of accumulated deformation was conducted. It is shown that large accumulated deformation occurs during the long-term traffic loading process. The additional stress transferred to the silt subgrade decreases greatly when passing through the pavement structure. Then, the addition stress decreases further to about 10% of the maximum additional stress within the silt subgrade with the thickness of 1.5m. Therefore, the subgrade with the thickness of 1.5m can be considered as the principal working area to sustain the traffic loads.