基于一次二阶矩的冻融作用下沥青路面性能可靠度分析

Applying first order second moment to solve the reliability of asphalt pavement performance under freeze-thaw impacts

温度裂缝与水损坏是寒冷地区沥青路面常见的病害形式,对路面性能有重要影响。通过冻融循环试验模拟,分析了温度与水分冻融环境对沥青混合料性能的影响;基于沥青路面结构可靠度方程,通过考虑影响因素不确定性,采用一次二阶矩法求解路面结构强度可靠度功能函数,对沥青路面结构的可靠性展开研究。研究结果表明:沥青混合料的抗压回弹模量随冻融循环作用次数的增加呈减小趋势;路面结构可靠度随冻融循环次数的增加也呈降低趋势,冻融循环作用对路面结构的可靠度有显著影响;冻融循环变异系数取值对路面结构可靠度也有一定影响;在实际工程分析中应重视外界环境的影响。

Thermal cracks and moisture distresses are principal distress forms of asphalt pavement in cold regions, which have a significant impact on asphalt pavement performance. In this paper, freeze-thaw （F- T） cycle test was used to simulate and analyze the impact of environment temperature and moisture on asphalt mixture performance. Based on the asphalt pavement reliability function and the uncertainties of influencing factor the first order second moment （FOSM） method was employed to solve the performance function of the pavement structural strength and reliability and the research on the asphalt pavement reliability was carried out. Analytical results show that the resilient modulus of asphalt concrete mixture declines with the increase of F-T cycle. F-T cycle has a significant impact on estimating reliability, which declines with the increase of F-T cycle. Besides, the value of variation coefficient of freeze-thaw cycle also has some influence on the reliability of pavement structure. As a result, environment and other influence factors should not be neglected in the practical engineering analysis. 2 tabs, 4 figs, 19 refs.