脱空状态下接缝传荷系统服役规律及机制研究

Research on Service Law and Mechanism of Joint Load Transfer System under Void Conditions

摘要: 厘清复合式路面脱空状态下接缝传荷系统服役规律及工作机制，对于脱空病害的处治及复合式路面结构设计具有重要意义。本文构建了含弹簧单元的三维有限元模型，通过批量设置弹簧、连接器单元实现了复合式路面接缝传荷系统的模拟，对比分析了板角半脱空、板角全脱空下不同弹簧刚度的弯沉及接缝传荷系数变化规律，并对连接器单元的三向应力分布规律进行了分析。结论表明：脱空尺寸不变，弯沉和接缝传荷系数随弹簧刚度总体增加而减小，弹簧刚度宜在0.5q~5q范围内；弹簧刚度不变，接缝传荷系数随脱空尺寸增加而减小，弯沉随脱空尺寸增加而增加，脱空尺寸在400~800 mm时，弯沉迅速增加；接缝传荷系统工作特点为局部协同工作机制，弹簧并非同时参与工作，而是以脱空局部区域为中心，随着脱空区域板角挠度的增加，邻近的弹簧由近及远分批地协同参与工作。

Abstract: Clarifying the service law and working mechanism of the joint load transfer system in composite pavements under void conditions is of great significance for void treatment and structural design of composite pavements. In this study, a three-dimensional finite element model incorporating spring elements was established. The joint load transfer system of the composite pavement was simulated by employing spring elements and connector elements in batches. A comparative analysis was conducted on the variations in deflection and joint load transfer efficiency under partial corner voids and full corner voids with different spring stiffness levels. In addition, the triaxial stress distribution of the connector elements was analyzed. The results show that when the void size remains constant, deflection and joint load transfer efficiency generally decrease with increasing spring stiffness, and the recommended spring stiffness ranges from 0.5q to 5q. When the spring stiffness is constant, joint load transfer efficiency decreases with increasing void size, while deflection increases. Deflection increases rapidly when the void size ranges from 400 mm to 800 mm. The joint load transfer system exhibits a localized cooperative working mechanism. The spring elements do not engage simultaneously. Instead, they are activated in a coordinated manner from near to far, centered around the localized void area, as the deflection ratio at the slab corner increases.