Collapse Safety Reserve And Performance Improvement Of Long-term Serving Jacket Platform

Since short construction period,simple design process and relative low cost,jacket offshore platform is widely used for production of marine resource in China.The service life of the platform is generally long and many platform structures are located in areas with high seismic hazard,the influence of seismic must be taken into decision making when the platform is designed.At present,the safety analysis of the jacket platform under the action of the earthquake is not comprehensive.In order to ensure the safety of the platform,a typical jacket platform is chosen as the research object of this paper,and carried out a series of safety analysis of jacket platform under the action of seismic.The main contents of the paper are as follows:In this paper,detailed description of several security reserves and theirs calculation method is given.This paper summarizes the main research status of the importance of component analysis,and briefly introduces the method of improving the seismic performance of the jacket platform,and puts forward some suggestions on how to improve the performance of the jacket platform.In addition,In this paper,the problems such as the double damage of the jacket platform under the action of corrosion and earthquake are briefly discussed.The method of improving the seismic performance of the jacket platform based on the weak position is proposed,the method of determining the weak layer of the jacket platform with the component importance and interlayer displacement angle is made.The validity of the method is proved by numerical experiments.Considering the dual effects resulted from earthquake and corrosion,corrosion model considering different corrosion zone and time-in-service is set up.The results show that the influence of corrosion on the seismic safety performance of the jacket platform cannot be neglected.The reliability of the corrosion model established in this paper is verified.This paper puts forward the improvement of the numerical simulation of the progressive collapse of offshore platform under the seismic load,and point out that a more practical scene of gradually failure of the elements and progressive collapse of the whole structure can be reflected by modifying of the structural model during the analyzing process.The idea of progressive collapse simulation based on component removal is proposed.