深水导管架平台结构动力推覆分析方法

针对动力放大效应明显的深水导管架平台，将非线性动力分析与传统Pushover相结合，提出动力推覆分析（DPA）方法，用于研究平台结构极限承载能力及倒塌力学行为。提出安定状态的概念，作为平台动力倒塌的临界判据，引入动强度储备比和动载比等指标，建立了完善的DPA评估体系。以某深水导管架平台为例，分别从平台极限承载能力、位移响应以及失效模式3个方面对DPA和传统Pushover方法进行对比分析。结果表明：考虑动力放大效应后，基于DPA评估的平台极限位移增大，强度储备有所降低，相比Pushover方法，评估精度更高；DPA与Pushover方法所得到的塑性分布基本相同，载荷动态效应不会改变平台结构的失效模式；DPA能够更好地反映环境载荷动态历程，有效追踪平台结构的倒塌失效过程。

Dynamic pushover analysis method of deep-water jacket platform

Aiming at the deep-water jacket platforms with significant dynamic amplification, Dynamic Pushover Analysis(DPA) method was proposed based on nonlinear dynamic analysis and traditional Pushover analysis, and used to estimate the ultimate bearing capacity and collapse mechanical behavior of deep-water jacket platforms. The concept of shakedown was put forward as the critical criterion of platform dynamic collapse. Dynamic Reserve Strength Ratio, Dynamic Load Ratio and other indicators were introduced, so as to establish the perfect DPA evaluation system. Taking a certain deep-water jacket platform as an example, a deeply comparative analysis was conducted between DPA and traditional Pushover method from three aspects of platform ultimate bearing capacity, displacement response and failure mode. The results show that with consideration of dynamic amplification and based on DPA evaluation, the platform ultimate displacement is increased, and the reserve strength is reduced; the evaluation precision is higher as compared with Pushover analysis results. The plastic distribution obtained by DPA and Pushover is basically similar, and the loading dynamic effect is unable to change the failure mode of platform structure. DPA can better reflect the dynamic process of environmental loading, so as to effectively track the collapse failure process of platform structures.