温度场下城市沥青路面车辙成因力学机理分析

发布时间：2018-04-30 03:08

  本文选题：城市道路 + 沥青路面　； 参考：《中南大学》2014年硕士论文

【摘要】：随着汽车数量的急剧增加,人们对城市道路系统量和质的要求也不断提高。作为城市道路沥青路面主要的破损形式之一,沥青路面车辙问题越来越受到人们的关注。现有城市沥青路面车辙的研究大多是基于恒定温度条件进行的,忽略了周期变化的气候和交通条件对沥青路面车辙产生、发展的影响。 本文首先以长沙市部分城市主干道为背景,现场调查了部分主干道的路面交通和车辙状况,结合对车辙类型和形成机理的分析,探讨城市沥青路面车辙成因、特点及影响因素。 其次,采用ABAQUS建立了沥青路面结构三维有限元模型,以长沙多年的月平均气象数据为边界条件,利用DFLUX和FILM子程序实现对沥青路面温度场的日变化分析。计算结果显示：温度的不断变化,引起沥青路面结构沿路面厚度方向产生较大的温度梯度,使路面各结构层的温度分布存在不均匀性和不稳定性。 最后,编写DLOAD和UTRACLOAD子程序施加移动荷载,对温度场条件下不同荷载组合的路面力学响应进行了对比分析,并探讨了不同温度场、车速、水平荷载和接地压力对力学响应的影响。结合温度场条件下的累计荷载作用下车辙日变化规律及影响因素分析,得出交叉口沥青路面车辙产生的力学机理。结果表明：水平荷载作用下,沥青面层表面显著增大的水平剪应力是导致交叉口路面车辙的主要原因。车辙发展是具有温度区间效应的,气温超过25℃后沥青混合料的抗剪强度和模量会随温度升高而急剧下降,从而导致车辙的显著发展。水平剪应力和车辙量均随着车速的减小和水平荷载系数、接地压力的增大而递增。
[Abstract]:With the rapid increase in the number of cars, the demand for the quantity and quality of urban road system is also increasing. As one of the main damaged forms of urban asphalt pavement, people pay more and more attention to rutting of asphalt pavement. Most of the existing researches on the rutting of urban asphalt pavement are based on constant temperature conditions, ignoring the influence of periodic climate and traffic conditions on the rutting and development of asphalt pavement. Based on the background of some urban main roads in Changsha, this paper investigates the traffic and rutting situation of some main roads on the spot, analyzes the rutting types and formation mechanism, and probes into the causes, characteristics and influencing factors of rutting in urban asphalt pavement. Secondly, the three-dimensional finite element model of asphalt pavement structure is established by using ABAQUS. Based on the monthly average meteorological data of Changsha for many years, the daily variation of temperature field of asphalt pavement is analyzed by using DFLUX and FILM subroutine. The calculation results show that the continuous change of temperature leads to a large temperature gradient along the road surface thickness direction of asphalt pavement structure and makes the temperature distribution of each structure layer of the pavement uneven and unstable. Finally, DLOAD and UTRACLOAD subroutines are compiled to apply moving load to analyze the mechanical response of pavement under different load combinations under temperature field, and the effects of different temperature field, speed, horizontal load and grounding pressure on the mechanical response are discussed. Based on the analysis of the rut diurnal variation and its influencing factors under the accumulative load under the condition of temperature field, the mechanical mechanism of rutting of asphalt pavement at intersection is obtained. The results show that the obvious increase of horizontal shear stress on the surface of asphalt surface is the main reason for rutting of intersection pavement under horizontal load. Rutting development has the effect of temperature range. When the temperature exceeds 25 鈩，

本文编号：1822792