不同类型近破波作用下沉箱式防波堤的振动-提离摇摆运动

倾覆失稳是沉箱式防波堤的主要破坏形式之一,是稳定性验算的基本内容·　采用质量_弹簧_阻尼器集总参数模型模拟沉箱式防波堤在单峰值冲击型、双峰值冲击型和冲击_振荡衰减型等不同类型近破波作用下的振动_提离摇摆运动过程,研究了不同类型近破波和沉箱的提离摇摆运动对沉箱式防波堤动力响应的影响·　结果表明,在近破波冲击力幅值相同的条件下,近破波类型对沉箱的动力响应影响很大;提离摇摆运动虽然会使沉箱的转角幅值增大,但可有效地减小沉箱的位移、滑移力和倾覆力矩幅值·　研究成果为允许沉箱式防波堤出现提离摇摆运动的设计概念提供了理论基础·

Vibrating-Uplift Rocking Motion of Caisson Breakwaters Under Various Breaking Wave Impact Forces

Overturning is one of principal failure types of caisson breakwaters and is an essential content of stability examination in caisson breakwater design. The mass_spring_dashpot model of caisson_foundation system is used to simulate the vibrating_uplift rocking motion of caisson under various types of breaking wave impact forces, i.e., single peak impact force, double peak impact force, and shock_damping oscillation impact force. The effects of various breaking wave types and the uplift rocking motion on dynamic response behaviors of caisson breakwaters are investigated. It is shown that the dynamic responses of a caisson are significantly different under different types of breaking wave impact forces even when the amplitudes of impact forces are equal. Though the rotation of a caisson is larger due to the uplift rocking motion, the displacement, the sliding force and the overturning moment of the caisson are significantly reduced. It provides the theoretical base for the design idea that the uplift rocking motion of caisson is allowed in design.