加宽工程路面开裂影响因素的数值分析

基于线弹性断裂力学,使用大型有限元软件ABAQUS对加宽工程路面在2种荷载作用模式下开裂的影响因素进行了分析.对沥青面层厚度和模量的分析结果表明,偏荷载对面层裂缝扩展的影响比正荷载大,增加面层厚度和减小面层模量能降低面层反射裂缝应力强度因子.对老路基层和新路基层模量的分析结果表明新老路基层模量相同时,应力强度因子K2数值最小,几乎为零,并随裂缝扩展长度变化不大,面层反射裂缝扩展的可能性最小,因此,选择合适的新路面结构使其模量与老路基层模量相同是非常重要的.此外,随差异沉降增加,应力强度因子K2略有增大,并且差异沉降越大,K2增大得越明显.这表明除合理选择路面结构外,进行地基处理降低差异沉降也非常重要.

Analysis of influence factors of widening pavement cracking

Based on the linear elastic fracture mechanics,the paper analyses the influence factors of widening pavement cracking under two load modes using the computer package ABAQUS.The results of analyzing the pavement surface show that influence under bias load is bigger than middle load,and the thickness increase and modulus decrease of surface can reduce the stress intensity factor.The results of contrasting the old and the new pavement base show that when the old and new base has a uniform modulus the value of stress intensity factor K2 is minimum,almost equals zero,and will change very little with the length of cracking.At the same time,the possibility of reflective cracking development declines.Thus,selecting proper pavement type and making the modulus of the old and new pavement identical are very important.In addition,the differential settlement can enhance the stress intensity factor.Accordingly,besides reasonable selection of pavement type,it is important to treat the soft foundation properly to reduce the differential settlement.