水泥混凝土路面板角脱空判定指标

Criterion for void identification beneath cement concrete pavement slab corner

以ANSYS有限元计算软件为基础,利用FWD(Falling weight deflectometer)板中板角实测弯沉值,建立以板角弯沉为判定指标的板角脱空范围估算方法。对均匀支承的无限大板板角理论弯沉值修正平面尺寸效应和板间接缝传荷能力,求解理论板角弯沉值,将其与FWD实测板角弯沉值相比较以评定路面板角脱空状况;提出板角脱空指数λ,并分析λ与脱空尺寸、面板模量、面板厚度和地基反应模量的相关性,建立λ与脱空尺寸的回归关系式估算脱空尺寸。对湖南耒宜高速公路试验段板角脱空识别结果与实际钻芯结果进行对比,发现最大相对误差为6.32%,与检测结果较吻合,表明该方法具有较高的可靠性,能为水泥混凝土路面板底脱空的识别提供合理、可行的新思路和手段。

Based on ANSYS and field FWD （Falling weight deflectometer） deflection testing data for the center and the comer of the slab, a method was established to estimate void scope beneath slab comer. Its criterion of judgment was the deflection in slab comer. By modifying the effect between slab planar dimension and load-transfer efficiency to the theoretical slab comer deflection of both in infinite site slab and good bearing conditions, the theoretical slab comer deflection was calculated and compared with field FWD testing data to estimate the void conditions beneath slab comer. A concept of void index was initiated, and it is defined as the ratio of deflections of field testing in slab comer under FWD load against theoretical deflections. Considering the relationship between void index and some factors such as void size, slab modulus, slab thickness and foundation reaction modulus, the regression formula between void index and void size was established for estimation of void size. The results show that the biggest error is 6.32% between the results of void identification and that of core-drilling for the test road of Hunan Leiyi Expressway, which fits perfectly with the actual results. The agreement between both results indicates that the method is reliable and provides new ideas and means for void identification under cement concrete pavement comer.