海洋环境荷载下半潜式平台上承房屋钢框架结构的动力响应特征

以1 000 m深海半潜式平台上承房屋钢框架结构为研究对象，首先采用有限元方法模拟了3层、6层、9层3种高度的上承结构在100年一遇极端海洋环境荷载作用下的动力时程响应，获得较适宜的推荐高度；然后对推荐高度结构分别进行陆地地震作用及海洋环境荷载作用下的动力时程响应有限元模拟，并将两种支承条件与作用方式下房屋钢框架结构的动力时程响应结果进行对比。结果表明：海洋环境荷载作用下，3层和6层结构的动力响应水平都相对较小且差距不大，而9层结构的动力响应水平因海风及结构倾斜影响过大而比6层结构的有显著增大，据此选定6层高度作为较适宜的推荐高度；6层房屋钢框架结构在平台支承4个月一遇海况下与在陆地支承8度多遇地震下的动力响应水平总体基本相当，但与陆地支承8度罕遇地震动力响应水平相比，即使是100年一遇的极端海洋环境荷载作用，其动力响应水平总体上也明显小于前者；研究成果可为海洋平台上承结构物的设计提供参考。

Dynamic Response Characteristics of Steel Frame House Structure on Semi-submersible Platform Under Ocean Environmental Load

The steel frame house structure on the semi-submersible platform suitable for 1000 m deep sea was taken as the research object. Firstly, the finite element method was used to simulate the dynamic time-history response of three-story, six-story and nine-story top structures under the ocean environmental load of one-hundred-year return period sea condition, and the suitable recommended height was obtained. Then the dynamic time-history response of the recommended height structure under the actions of both land earthquake and ocean environmental load was simulated by finite element method, and the results of dynamic time-history response under the two supporting conditions and action modes were compared. The results show that, under the ocean environmental load, the dynamic response levels of the three-story and six-story structures are relatively small and the difference is not big, while the dynamic response level of the nine-story structure is significantly higher than that of the six-story structure due to the large influence of sea breeze and structural slant. Thus the six-story height is selected as the recommended height. The dynamic response levels of the six-story steel frame house structure under the four-month return period ocean environmental load and 8 degrees frequent earthquake are similar, while the dynamic response level of even one-hundred-year return period ocean environmental load is lower than that of 8 degrees rare earthquake. The research findings can provide a reference for the design of the top structures on offshore platform.