浮筒辅助大型导管架结构整体拆除上浮过程动力响应特征研究

浮筒辅助大型导管架结构整体拆除作业是一个连续过程，作业过程中拆除系统的动力荷载及动力参数均会发生显著变化，传统基于某一稳定状态的结构动力响应分析方法不能准确预测拆除系统上浮过程中的动力响应。通过建立浮筒辅助大型导管架结构整体拆除上浮过程动态分析模型，对拆除系统上浮过程的动力响应特性进行研究。结果表明，整体拆除动态分析模型可以准确描述拆除系统上浮过程中浮筒及导管架浮力变化对上浮高度的影响机制，拆除系统上浮高度约为不考虑浮筒和导管架浮力变化时的90%。此外，浮筒辅助大型导管架整体拆除方法的动态稳定性较强，四级海况下拆除系统的最大偏移量仅为4.2 m，有较好的工程应用前景。

Study on the dynamic response characteristics of the pontoon-assisted large-scaled jacket platform removal

The pontoon-assisted jacket platform removal is a continuous process, and the dynamic load and the dynamic characteristics of the removal system therefore change significantly in the de-ballasting process of pontoons. The conventional method based on a specific stable state cannot predict the dynamic response of the removal system accurately. The time-varying mass point is adopted to characterize the de-ballasting process of the pontoons, and a numerical model of the pontoon-assisted large-scaled jacket platform removal is established, and the dynamic response characteristics of the removal system are investigated with the numerical model. The results show that the numerical model can describe the influence of the pontoon and jacket platform''s buoyancy change on the floating height of the removal system, and the floating height of the removal system is about 90% compared with that when the buoyancy change of the buoy and jacket is not considered. In addition, the maximum offset of the removal system under the four-class sea conditions is just 4.2 m, and this indicates that the pontoon-assisted large-scaled jacket platform removal method has good environmental adaptability, which has excellent engineering application prospects.