Stress condition of the elements of support blocks of fixed offshore platforms and resource evaluation of them

Abstract

The article analyzes the factors causing the stress state of the support blocks of fixed offshore platforms (FOPs). The data on the wind-wave regime of the Subbotinsky field of the Black Sea are analyzed, the parameters are determined and the cycles of wind-wave loads acting on the platform are systematized. Using the StructureCAD software package, the values of the effective equivalent stresses were determined from the weight of the structural elements of the FOP, the installed technological equipment, the floating forces of the aquatic environment and wind-wave loads under various conditions of the orientation of the wave beam with respect to the support block. Various design options for FOPs are analyzed and the problem of finding “zero elements” is solved. The proposed solutions will allow developing a comprehensive methodology for assessing the stress state of the support block of the FOP. Besides, for the purpose of determining the resource of the elements, the values of the equivalent stresses of the columns, horizontal belts and braces of the support block of the FOP are determined. The example of calculating the resource of platform elements is given.