半刚性基层裂缝无损监测与评价技术研究

Research on Non-destructive Monitoring and Evaluation of Crack in Semi-rigid Base

目前半刚性基层裂缝无损评价技术尚不成熟,无法科学高效地判断基层损坏情况。文中通过室内试验采用分布式光纤传感器监测水泥稳定级配碎石小梁结构应变,提出半刚性基层裂缝无损监测技术。依托某高速公路实体工程,采用传统检测手段获得各结构层质量评定指标,建立半刚性基层损坏状况无损评价方法,结果表明,分布式光纤可以对基层裂缝的位置及大小进行有效监测,在实际铺设过程中应该加以封装保护,以提高光纤在实际应用中的成功率。基层表面弯沉与其损坏状况具有显著相关性,通过基层表面弯沉可以推断出其损坏状况及特征。基层模量衰减比与其损坏状况在双对数坐标系下具有良好的线性相关关系,通过面层弯沉盆可以反演基层模量,进而实现基层状况无损评价。

At present,the non-destructive evaluation technology of semi-rigid base crack is not mature,which can not judge the damage of base scientifically and efficiently.In this paper,the distributed optical fiber sensor is used to monitor the strain of cement-stabilized graded crushed stone beam through laboratory tests,and the non-destructive monitoring technology of semi-rigid base crack is proposed.Based on a highway physical project,the quality evaluation index of each structural layer was obtained by traditional detection means,and a non-destructive evaluation method was established for the damage condition of semi-rigid base.The results showed that distributed optical fiber could effectively monitor the location and size of the base crack,and should be packaged and protected during the actual laying process to improve the survival rate of optical fiber in practical application.There is a significant correlation between the surface deflection of the base and its damage condition,and the damage condition and characteristics can be inferred from the surface deflection of the base.The attenuation ratio of the base modulus has a good linear correlation with the damage condition in the double logarithmic coordinate system.The base modulus can be retrieved by the surface layer deflection basin,and the objective of the non-destructive evaluation of the base condition can be realized.