同板动弯沉差脱空判别方法和标准

针对目前脱空判别方法在实际工程应用中的不足，为了准确定量地判定水泥板底脱空，提出了采用同板板边中点一板中弯沉差和板角一板中弯沉差为判别指标的脱空判定方法。采用ANSYS有限元法建立了板边脱空和板角脱空三维模型，模拟FWD加载效果，计算了在不同脱空深度、脱空面积和传荷能力下的板边中点、板中、板角弯沉值，得出了板边、板角与板中的弯沉差范围；以烟威高速公路为依托，对FWD弯沉检测数据进行统计分析，参考理论计算和钻芯取样结果，给出了同板弯沉差判别标准和传荷能力修正系数，并通过试验路验证了所提标准的可行性，结果表明：ANSYS有限元理论模拟值符合工程实际，所提标准板边弯沉差的准确度为88．5％，板角弯沉差的准确度为84．6％。该方法是在同一条件下进行分析评定，消除了大部分弯沉影响因素引起的变异性，可以分级评定脱空严重程度，更好地指导水泥路面养护维修。

Determination Method and Criterion for Voids by Dynamic Deflection Difference in the Same Cement Slab

Aiming at applications, in order proposed with slab ed the lack of to accurately current determination quantify the voids beneath method for voids in practical engineering cement slab, the determination method was ge - slab center deflection difference and slab corner - slab center deflection difference in the same cement slab for voids. Three-dimensional models were set up using the ANSYS finite element method for voids beneath slab corner and slab edge. And the load was simulated with FWD test results. Thereafter, the deflection values were calculated in slab center, slab corner, slab edge under different void depth, void area and load transfer capacity. And the range of deflection diffidence was obtained. With Yantai-Weihai expressway, detection data for deflection using Falling Weight Deflectometer were statistically analyzed. And the criteria and correction factors of load transfer capacity were given with simulation and samples analysis. The feasibility of criteria was verified by actual test data. It is found that the simulation values and the test values are in good agreement. The accuracy of void determination by lab edge - slab center deflection difference and slab corner - slab center deflection difference are 88.5 % and 84. 6%, respectively, which meet the engineering requirements. The voids were determined under the same conditions with the elimination of deflection variability.