沥青路面路基结构组合优化力学数值探析

Analysis of the Structural Combination Optimization of Asphalt Pavement

采用ABAQUS建立了沥青路面结构的三维有限元模型,对典型沥青路面的动力学特征进行了模拟计算,通过分析路面结构动力响应量和结构参数的关系,获得了两者的正负相关性,并提出了改善路面结构受力状态的有效途径。研究结果表明:面层模量一定时,随基层模量的增加,路表弯沉下降,半刚性路面和组合式路面基层层底应力增加;当基层模量一定时,随面层模量的增加,半刚性路面路表弯沉的变化较小,倒桩式路面和组合式路面路表弯沉变化明显,且组合式路面的基层层底应力明显提高;随基层模量增大,半刚性路面收底基层层底应力变化显著,受面层模量影响较小;当面层模量达到2 000 MPa后,基层模量对倒桩式路面底基层层底应力影响可忽略;面层模量较高时,基层模量和面层模量的增加,组合式路面的底基层底应力减小;随基层厚度的增加,路面各力学响应指标逐渐减小,基层厚度大于40 cm时,通过增加基层厚度来改善路面疲劳开裂效果减弱;基层厚度小于20 cm时,底基层的弯拉应力较大,路面基层为主承重层,承担较大的荷载作用,因而可通过提高基层厚度来抑制弯拉破坏,改善基层受力。

in this paper,using ABAQUS to establish a three-dimensional finite element model of asphalt pavement,the typical asphalt roadbed dynamic characteristics of the simulation calculation,based on the analysis of dynamic response of pavement structure and structure parameters,the relationship between the both positive and negative correlation,and put forward the effective ways to improve the pavement structure bearing state. The research results show that the surface layer modulus must,with the increase of the modulus at the grass-roots level,the road table deflection down,semi-rigid pavement and composite pavement base layer bottom stress increases; When modulus must be at the grass-roots level,with the increase of the surface layer modulus,the semi-rigid pavement road deflection change smaller,pour pile type pavement and composite pavement road deflection changes significantly,and composite pavement base layer bottom stress increased significantly; At the base level,the stress variation of the bottom layer of semi-rigid pavement is significant,and the surface layer modulus is less affected. The number of molds in the face is 2 000 MPa. At the base level,the effect of the bottom layer stress on the bottom layer of the pile pavement is negligible. When the surface layer modulus is high,the base level modulus and the surface layer modulus increase,and the bottom layer of the combination surface is reduced; With the increase of the thickness at the grass-roots level,the pavement mechanical response index decreases,the grass-roots thickness more than 40 cm,by increasing the thickness at the grass-roots level to improve the pavement fatigue cracking effect; Grass-roots thickness less than 20 cm,base layerof bending tensile stress is larger,the roadbase main bearing layer,bear a larger load,by improving the thickness at the grass-roots level to restrain flexural failure,improve the stress at the grass-roots level.