基于断裂力学的应力吸收层开裂特性  

Cracking characteristics of stress absorbing layer based on fracture mechanics

作　　者：马培建[1] 徐真真[2] 曹高尚[2] 

机构地区：[1]青岛理工大学土木工程学院,山东青岛266033 [2]天津市市政工程设计研究院,天津300051

出　　处：《长安大学学报（自然科学版）》2013年第5期32-38,共7页Journal of Chang’an University(Natural Science Edition)

基　　金：国家自然科学基金项目(51008033);交通运输部西部交通建设科技项目(2005 318 812 13);中央高校基本科研业务费专项资金项目(CHD2011ZD017)

摘　　要：为了对应力吸收层材料开裂机理及特性进行分析,通过在冲击破碎后加铺层路面应力吸收层层底植入一定长度的初始裂纹,采用三维有限元方法及断裂力学计算初始裂纹尖端应力场强度在荷载、温度及耦合条件下的变化,得到临界开裂荷位、开裂形式及开裂主导因素,提出应力吸收层材料抗开裂性能评价指标,并给出相应的参考韧度值。研究结果表明:行车荷载产生以滑开型为主的开裂形式,温度荷载产生以张开型为主的开裂形式;温度是导致应力吸收层开裂的主导因素;推荐以断裂韧度作为应力吸收层抗开裂性能评价指标,断裂韧度要求值KC≥0.107 2MPa·m1/2。In order to analyze the cracking mechanism and characteristic of stress absorbing layer, after an initial crack was implanted at the bottom of stress absorbing layer in impaction overlay pavement. Three dimensional finite element method and fracture mechanics were used to get the crack tip stress field intensities under different load positions, temperatures and coupling condi- tions in overlay model. Then the critical load position, cracking types and dominant cracking fac- tor of stress absorbing layer were gotten, based on which, an evaluation index was put forward for anti-crack performance of stress absorbing layer, and corresponding reference toughness was also given. The results show that sliding cracking is the main type generated by traffic load and o- pening cracking is the main type generated by temperature load; temperature is the dominant fac- tor of cracking; fracture toughness is recommended as anti-cracking performance evaluation index of stress absorbing layer and required fracture toughness value is Kc≥0.1072MPa·m^1/2. 4 tabs, 12 figs, 13 refs.

关 键 词：道路工程 断裂韧度 断裂力学 应力吸收层 反射裂缝 评价指标 

分 类 号：U418.8[交通运输工程—道路与铁道工程]