级配碎石基层塑性变形预估模型

Prediction Model for Plastic Deformation of Graded Crushed Stone Base

基于Pérez永久变形预估模型,以初始塑性应变为因变量,建立了包含荷载作用次数和级配碎石厚度的塑性变形预估模型;根据塑性变形试验结果对模型系数进行了标定;基于等效换算原理,建立了0.7 MPa标准轮压ps下的第60 min的塑性变形量d60,ps等效转化为p应力水平下第60 min的塑性变形量d60,p的关系;应用分层总和法的原理,最终建立了级配碎石基层塑性变形预估模型,并进行工程实例应用分析。结果表明:级配、含水率、应力水平几乎对模型系数没有影响,级配碎石基层塑性变形预估模型具有通用性,能客观反映级配碎石基层塑性变形发展规律,可供沥青路面级配碎石基层的结构设计参考。

Based on the permanent deformation prediction model established by Pérez,the initial plastic strain is proposed as the dependent variable and the initial plastic strain prediction model including the number of loads repetition and the thickness of graded crushed stone(GCS)is established.Model coefficient of the prediction model were calibrated by using test results of plastic deformation of GCS.According to the principle of equivalent conversion,the plastic deformation in the 60th min under the standard wheel pressure of 0.7 MPa(d60,ps)and the plastic deformation in the 60th min under the stress of p(d60,p)was established.Finally,the prediction model for plastic deformation of GCS base was established based on the principle layer-wise summation method,and analyzed by engineering example.The results show that the aggregate gradation,moisture content and load stress have almost no effect on model coefficients,and the prediction model for plastic deformation of GCS base is universal;the developed model can objectively reflect the development law of plastic deformation of GCS base,which can serve for guiding the structural design of asphalt pavement with GCS base.