基于FWD的半刚性基层开裂状况无损评价模型

为无损判别半刚性基层开裂状况，以落锤式弯沉仪(FWD)为平台反演基层模量，分析弯沉盆匹配法和规律法模量反演结果的差异，进行基层反演模量与开裂状况的相关性分析，以基层模量比为评价指标，建立基层开裂状况无损评价模型和评价标准。研究表明：铣刨后的半刚性基层表面可视化损坏模式主要为裂缝；与弯沉盆匹配法相比，弯沉盆规律法的模量反演结果唯一且土基模量变异性较低；基层模量比与基层开裂状况在半对数坐标下具有良好的线性关系；基层开裂状况可分为四类，基层模量比分界值分别为0.68、0.47、0.30。该评价模型适用于不同强度的半刚性基层损坏状况的无损判别，可为路面大中修设计是否翻修半刚性基层提供决策支持。

A nondestructive evaluation model based on FWD for semi-rigid base#br#cracking condition

To nondestructively evaluate the semi-rigid base cracking condition, the falling weight deflectometer (FWD) was used as a platform to back calculate the base modulus, the difference in back-calculated modulus between basin matching algorithm and law algorithm was compared, and the correlation between back-calculated modulus and cracking condition of base was analyzed. Furthermore, the base modulus ratio was used as the evaluation indicator to develop the evaluation model and evaluation criteria for base cracking condition. The results show that, the visual damages of semi-rigid base after milling are mainly cracks. Compared with the basin matching algorithm, the solution obtained by the basin law algorithm shall be unique and the variability of the subgrade modulus is relatively low. The base modulus ratio has a good linear relationship with base cracking condition in the semi-logarithmic coordinates. The base cracking condition can be divided into four categories based on the boundary values of the base modulus ratio of 0.68, 0.47 and 0.30. The proposed model is applicable to the evaluation of the cracking condition of semi-rigid base with different stiffness, which can be referred when deciding whether to renovate the semi-rigid base  in the pavement rehabilitation design.