波音777型飞机载荷下机场跑道实测动力响应

Analysis of Measured Dynamic Response of Airport Runway Under Boeing 777 Loading

摘要:

对丹佛国际机场跑道实测道面应变以及弯沉信号进行分析，研究了波音777型飞机在跑道上滑行时跑道的动力响应.结果表明：轮载离传感器越近，道面应变和弯沉测量值越大；横缝附近处弯沉有3个峰值点，对应飞机的3个轮轴，而纵缝板边中部和板中心处的弯沉呈半正弦形状，只有1个峰值；在横缝板边加载时，相邻的未加载板与基层间发生脱空；地基沉降占总沉降量的主要部分，3.05~6.10 m范围内地基发生的非弹性变形非常小，可将3.05 m深度以下的地基视为弹性地基；板横缝方向的应变表现为达到一定平台后有3次波动，而纵缝方向的应变表现为2次拉压转换，纵缝板边中部轮轴间的应变恢复显著，易发生疲劳破坏；板中部由于绑定效应引起中性面的偏移较大，而板边中性面偏移较小，故板边处可近似为脱离状态，板中心应考虑绑定效应.所得结论对机场跑道工程的优化设计与科学施工具有参考价值.

Abstract:

Pavement strain and deflection of Denver International Airport runway are analyzed to study dynamic response of the airport runway when Boeing777 taxiing on it. The results show that the closer the wheel loads from the sensor, the greater the strain and deflection. There are three peak points for the deflection curve of location near the transverse joint, corresponding to the aircraft’s three axles, while deflection curves for location near central slab and mid longitudinal joint are semi sinusoidal shaped, with only one peak point. When loading at transverse joint edge, void occurs between slab and base for neighboring slab without loading. Settlement of foundation takes up the main part of total settlement amount of pavement, inelastic deformation occurring in depth of 3.05~6.10 m range is very small, which implies that the ground below 3.05 m depth can be regarded as elastic foundation. Transverse strain of slab shows three times fluctuating after reaching a certain level, while longitudinal strain displays twice transforming between tension and compression, and strain recovery between wheel loads at longitudinal joint edge is significant, which means more prone to fatigue damage. Offset of neutral plane due to bonding effect is greater at central slab than at the edge, so the interface between slab and base at the edge can be considered as separated, while bound state is employed at the center. These conclusions are useful as guidance for the optimum design and scientific construction of airport runways.