直立式非灌浆桩腿导管架平台超常态振动研究

Investigation on the Excessive Vibration of a Jacket Type Offshore Platform with Ungrouted Vertical Piles

通过理论分析和有限元计算 ,提出了非灌浆桩腿导管架平台在不同状态下刚度的简化计算公式 ,揭示了具有直立式非灌浆桩腿的导管架平台桩、腿间的相对运动使平台的服役状态与设计模型发生的较大变化 ,使平台的动力特性偏离了设计值 ,导致平台在正常海况条件下发生了超常的振动。计算结果表明 ,桩、腿存在相对运动时 ,平台的一阶频率降低了 5 0 %左右 ,对环境荷载的响应增大了 6倍左右。

The formula for calculating the stiffness of the Jacket Type Offshore Platforms with ungrouted vertical lags is proposed in this paper. It is shown that the excessive vibration of the jacket type offshore platforms with ungrouted vertical lags is caused by the unexpected change of the structural stiffness as well as the impact between the piles and the lags. It is recommended that the vertical lags should be grouted to reduce the vibration.