基于静-动力分析相结合方法的桥梁桩基础地震反应分析及抗震性能评价

SEISMIC RESPONSE ANALYSIS AND SEISMIC PERFORMANCE EVALUATION ON BRIDGE PILE FOUNDATIONS BASED ON THE METHOD COMBINED STATIC WITH DYNAMIC ANALYSIS

针对强震下高速铁路桥梁桩基础抗震设计中存在的问题,对桩基础的抗震性能提出了多级设防目标并给出了相应的评价指标与合理取值。该文提出了两种计算模型:静力Pushover分析模型及动力SR分析模型。首先通过Pushover分析模型获得结构的能力曲线、性能点控制值及承台底平动与转动弹簧本构关系。然后采用动力SR分析模型输入地震波进行非线性时程反应分析,获得结构的响应值,并与能力曲线控制点对比评价桩基础的抗震性能。最后以高速铁路32 m简支箱梁桥墩为研究对象,通过实例验证了该法的可行性。

In view of existing questions in the aseismic design of high-speed railway bridge pile foundation under strong earthquakes, the aseismic performance of pile foundation based on a multilevel fortification goal is proposed and the corresponding evaluation index and rational values obtained. This paper presents two kinds of calculation model, a Static Pushover analysis model and a SR dynamic model. Firstly, the structure capacity curve, the performance control value and constitutive relation to translational springs, and the rotational springs at the bottom of the pile cap can be obtained by the Static Pushover analysis model. Secondly, structure response value can be attained by the nonlinear time history analysis using the SR dynamic model. The aseismic performance of pile foundation is evaluated by the comparison of control points on the capacity curve. With one pier of a 32 m simply-supported box girder bridge in high-speed railway as the research subject, the feasibility of the method is verified by case study.