基于足尺试验的机场沥青道面轮辙发展与预测

Development and Prediction of Ruts in Airport Asphalt Pavement Based on Full-Scale Test

轮辙是引起沥青道面过早破坏的重要因素,飞机地面滑行渠化交通显著,由轮辙病害引起的道面平整度与舒适性问题突出.为此,建立飞机轮组-地基-沥青道面结构体系仿真分析模型,提出适应轮组荷载特征的等效循环加载方式,依托NAPTF (National Airport Pavement Test Facility)足尺沥青道面轮辙试验,验证仿真结果的适用性与可靠性,并开展加载时间间隔与环境温度等多因素分析.研究结果表明:考虑轮载作用横向偏移效应,轮辙总宽度达到轮组宽度的3倍,轮辙断面曲线有多处转折点与以往单一凹陷面特征明显不同;循环加载时间间隔对轮辙发展影响显著,经过150 s间隔后沥青面层回弹变形趋于稳定,可兼顾分析效率需要;前10%循环加载次数对轮辙变形的贡献超过40.4%,可基于初始轮辙建立指数型轮辙发展预测公式,对循环加载全过程拟合度高于96.4%,轮辙分析效率有明显提高.

Ruts can be one of the key reasons for early damage of asphalt pavement.Due to the channelized traffic characteristics of aircraft taxiing,the evenness and comfort of airport pavement are notably affected by rut damage.In this paper,a simulation analysis model of aircraft landing gears-foundation-asphalt pavement system is established.An equivalent cyclical loading process is proposed according to the loading characteristic of landing gears.The feasibility and reliability of the simulation model are verified by the rut test result of full-scale asphalt pavement conducted by National Airport Pavement Test Facility(NAPTF).Factors such as the loading interval and environment temperature are then analyzed.The results show that due to lateral shift effect of landing gear load,the total width of the ruts reaches 3 times the width of the landing gears,and the rut section curve has many turning points,which is obviously different from those of the previous single concave surface.The cyclical loading interval has a remarkable influence on rut development.The rebound deformation of the asphalt surface course becomes stable after a loading interval of 150 s,which can meet the requirement of analysis efficiency.Since the first 10% number of cyclical loading contributes more than 40.4% of overall rut deformation,an exponential rut deformation prediction formula is derived based on initial ruts.The goodness of fit result during the whole cyclical loading process is over 96.4%,and the efficiency of rut analysis is dramatically increased.