改建加铺大粒径级配碎石基层沥青路面结构力学规律分析

Mechanical Response Analysis of Asphalt Pavement with Reconstructed and Overlaid Large-Graded Crushed Stone Base

摘要: 为探讨大粒径级配碎石(LGCS)基层沥青路面的力学响应特性，借助Mpave软件构建了层状弹性体系模型，并采用正交试验方法设计了49组不同的路面结构组合，系统分析了AC层与LGCS层的厚度以及各层模量对路面弯沉、AC层底部拉应变、LGCS层顶层位移、压应力、压应变及剪应变的影响。研究结果显示，各力学响应在荷载中心处呈对称分布，其中弯沉呈“W”形态，压应变呈“U”型，剪应变则呈“S”型分布；在所有参数中，AC层厚度对力学响应影响最大，LGCS层模量影响次之。基于多元线性回归，构建了6项响应指标的预测模型(最大R²达到0.792)，证实了结构参数对力学性能具有显著控制作用。本研究为LGCS基层沥青路面的结构优化提供了理论支持与设计参考。

Abstract: Understanding the mechanical behavior of asphalt pavements with large-graded crushed stone (LGCS) base courses is essential for optimizing structural design and improving service performance. In this study, a multilayer elastic system model was established using Mpave software to evaluate the mechanical response characteristics of asphalt pavements incorporating LGCS bases. An orthogonal experimental design comprising 49 pavement structure combinations was developed to systematically investigate the effects of asphalt concrete (AC) layer thickness, LGCS base thickness, and the elastic modulus of each layer on key mechanical indicators, including surface deflection, tensile strain at the bottom of the AC layer, vertical displacement, compressive stress, compressive strain, and shear strain at the top of the LGCS layer. The analysis results indicate that the mechanical responses are symmetrically distributed about the loading center, with surface deflection exhibiting a “W-shaped” profile, compressive strain following a “U-shaped” pattern, and shear strain presenting an “S-shaped” distribution. Among all structural parameters, the AC layer thickness has the most pronounced influence on mechanical responses, followed by the modulus of the LGCS base. Multiple linear regression models were developed to predict six response indices, achieving a maximum coefficient of determination (R²) of 0.792. The findings demonstrate that structural parameters exert a significant control effect on pavement mechanical performance, offering valuable theoretical guidance and practical references for the structural optimization of asphalt pavements with LGCS base courses.