变截面双肢薄壁高墩基础约束刚度动力识别方法

以汝郴高速公路山店江大桥1号高墩为工程背景，基于Rayleigh能量法和South—well频率合成法导出变截面双肢薄壁桥墩结构复合振动基频计算公式，将基频表示成各惯性元和变形元所组成子系统的频率合成。在此基础上建立结构基础约束刚度识别方法，利用结构固有基频和地基约束刚度的关系，采用脉动实验测得桥墩2个不同施工阶段的振动频率，估算出基础约束刚度，并与设计值进行比较，为桥梁桥基~k_T-质量评估提供了科学依据。

Dynamic identification method of foundation restraint stiffness of double- leg thin -walled tapered high pier

On the background of NO. 1 pier of Shan Dian river bridge in Ruchen highway, based on the combina- tion of Rayleigh and Southwell＇ s methods, the fundamental frequency calculation formulas of double -leg thin - walled tapered high pier were derived from energy method where the fundamental frequency was expressed as a composition of frequencies of each sub - system, consisting of a deformable component and an inertia component. Based on the relationship between fundamental frequency of structure and foundation restraint stiffness. The iden- tification method of foundation restraint stiffness can be established, and the foundation restraint stiffness couId be estimated through measuring the vibration frequency of piers under two different construction period with the help of oscillation experiments. Then, the results estimated are compared to the design value, which provides scientific basis for the evaluation of the construction quality of bridze foundation.