梁—墩—桩基的动力特性研究

对大跨度桥的连续刚构部分，应用有限元法建立了三维梁-墩-桩的力学模型，采用大型工程软件对其进行动力特性分析。首先对桩基模型进行合理简化，建立了桩基空间计算模型并计算其动力特性。其次建立刚构桥的动力分析模型，并对无桩、有桩基不考虑土对桩振动的影响和考虑桩土相互作用的计算模型的计算结果加以分析比较。结果表明，桥梁体系的第三阶频率主要受高墩的影响，桥梁桩基对该体系振动特性的影响不明显。

Vibration Characteristics of a 3-Dimensional Beam-Pier-Pile System

A mechanical model for a 3 dimensional beam pier pile system is proposed with finite element methods for a continuous rigid frame bridge to analyze its vibration characteristics. The pile soil system is simplified to build the space model and to calculate the dynamic behaviors of the system. Then the dynamic analysis model for the rigid frame bridge is set up. The dynamic behaviors of the rigid frame bridge are calculated and compared with different models, including that without considering the pile, that with pile base but without considering the effects of soil properties on vibration of the pile, and that with the interaction of the soil and the pile considered. The results show that the main factor affecting the third order frequencies are the properties of piles, but the properties of pile bases have not significant effects on the vibration characteristics of the beam pier pile system..