作用于平台桩腿的海冰屈曲破坏冰压力随机过程模型及其参数确定

冰对结构的作用过程是典型的随机过程。本文在冰压力过程为平稳过程的假设下，从渤海海冰对平台桩腿作用的大量实测冰压力数据中，选取了２１条冰屈曲破坏时的冰压力时程曲线，对它们进行谱分析后，得到了单点冰屈曲破坏的压力随机过程的谱密度，并确定了谱参数及其跟环境要素的关系，依据文献［１］中冰压力沿圆柱面的空间分布，建立了绕桩腿的冰压力随机场模型，并得到了作用于桩腿的总冰力随机过程及其谱密度。本文的研究成果为平台结构冰激随机振动和疲劳累积损伤分析提供了荷载基础

THE STOCHASTIC PROCESS MODEL OF ICE ACTING ON LEGS OF MARINE PLATFORM PRESENTING BULKING FAILURE AND DETERMINATION OF MODEL PARAMETERS

The action of ice on structures is a typical stochastic process. In this paper, under the hypothesis that the ice force process is a stationary one,21 pieces of ice force vs. time sampling lines in buckling failure mode are selected from large amount of field data of ice force acting on legs of platform at Bohai sea area. The spectrum density of ice force on a point is obtained through spectrum analysis of the sampling lines, and the relationship between the spectrum density parameters and environmental factors is determined. The stochastic field model of ice force encircling leg is established using the distribution of ice force on column in . Then the stochastic process and its spectrum density of total ice force on legs are obtained. The Aresults in this paper provide load model for structural random vibration analysis and fatigue damage accumulation analysis excited by ice.