基于可靠度的旧水泥路面加铺层设计优化

Optimization of overlay design of old cement pavement based on reliability

为了更加科学合理地进行旧水泥路面加铺混凝土层结构设计,充分考虑加铺设计过程中参数值的不确定性和变异性,利用有限元分析软件,提出了基于目标可靠度的加铺层设计优化方法。利用Sigma误差理论实现路面可靠度的计算,采用响应面法分析各设计变量(加铺层厚度、加铺层弹性模量、轮胎接触压力、旧路回弹模量、累计轴载作用次数)对加铺后路面可靠度的影响规律。结果表明,加铺后路面可靠性对轮胎接触压力和旧路回弹模量的敏感程度最高。在满足一级安全等级90%目标可靠度的条件下,给出了加铺层厚度、加铺层弹性模量和期望交通量的设计建议值。

In order to carry out a more scientific and rational structural design of the concrete layer of old cement pavement,the uncertainty and variability of the parameter values in the design process of the pavement addition were fully considered.Using finite element analysis software,an optimization method for the design of the pavement overlay based on the target reliability was proposed.Sigma error theory was used to realize the calculation of pavement reliability,and the response surface method was used to analyze the influence law of each design variable(thickness of overlay,elastic modulus of overlay,tire contact pressure,rebound modulus of old road,accumulative axle load action times) on the reliability of the pavement after overlay.The results show that the reliability of the pavement after surfacing is most sensitive to the tire contact pressure and the rebound modulus of the old road.The recommended design values for thickness of overlay,elastic modulus of overlay and desired traffic volume are given in graphical form under the condition that the target reliability of 90% of first-level safety level is met.