质量偏心和刚度偏心是结构偏心的两种重要形式,该文从单层平台结构体系在地震与波浪环境荷载作用下的一般振动方程出发,推导得到了可以考虑平台不同偏心形式的振动方程。在此基础上,针对不同水深的导管架海洋平台典型算例进行了数值计算,分析了三种荷载工况(地震作用、波浪作用、地震波浪耦合作用)时,平台结构的偏心形式、偏心率以及目标分析点的位置对偏心平台扭转耦联响应的影响规律,同时还分析了地震、波浪荷载强度对偏心平台扭转耦联响应的影响规律。分析结果表明:平台结构的偏心形式、目标点位置以及偏心率的大小都会影响偏心平台的扭转耦联响应,同时地震与波浪的联合作用对不同场地上不同周期类型的平台影响不尽相同,在某些情况下有必要考虑地震与波浪的联合作用对海洋平台进行抗震分析。
Mass eccentricity and stiffness eccentricity are two key forms of asymmetric structures. Based on the general dynamic equation of one-storey asymmetric offshore platform subjected to wave and earthquake loadings, the vibration equation considering different eccentricity forms is deduced in this paper. At different water depths, the performances of asymmetric platforms subjected to earthquake load, wave load, or simultaneously both, are numerically analyzed. The torsionally coupled effects are studied considering the variation in eccentricity form, eccentric ratio and target component's location. In addition, the influence of environmental action intensity on torsionally coupled effect is analyzed. The numerical results show that eccentricity form, eccentric ratio and target position have non-negligible influence on torsionally coupled effects. Furthermore, the influences of combined environmental actions are different for asymmetric platforms with different periods or in different foundation conditions.