Study On Dynamic Catastrophe And Structure Self Existence Ability Of Jacket Platform Under Super Typhoon

With the slowdown in the exploration volume of onshore oil,people are paying more and more attention to offshore oil and gas resources.The proportion of offshore oil resources to the total amount of global petroleum resources is gradually increasing.The development of oil and gas resources in the South China Sea is also in full swing.The jacket platform is the most widely used offshore oil and gas exploration and development equipment.The extreme load caused by super typhoon is more and more concerned about the damage of the jacket platform.This paper relies on the National Natural Science Foundation Program of ?Research on survivability and dynamic catastrophe emergency measures for fixed platforms under extreme marine environment?,and studies the dynamic catastrophic and self existence ability of jacket platform under super typhoon to provide a guarantee for platform survival and safety.In this paper,a complete test procedure is established through the wind tunnel aeroelastic test of the jacket platform,and the vibration response law of the derrick structure under aeroelastic effect is studied.Based on the digital wind tunnel simulation method verified by test,considering the damage evolution of the material and the waves in deck,the failure mechanism of the platform structure is revealed,and the continuous failure mode of the whole platform is studied.Considering the nonlinear coupling effect of pile soil and the nonlinear effect of material,a detailed analysis model of the collapse of the jacket platform is established,and the self existence ability of the platform structure is evaluated under the condition of random extreme load induced by super typhoon.Establish a performance-based structural wind-resistant design process,form multi-level platform wind-resistant fortification target,quantify the structural performance level indicators,and propose the cost objective function of the jacket platform to complete the safety performance evaluation of the example platform.The research results show that the dangerous angle of the offshore platform derrick structure is 270°,and the failure mode is that the narrow faces on both sides of the derrick are turned outward due to the squeezing caused by the derrick bending and the members break with the increase of the bending,and the failure mode of the derrick varies significantly with the wind direction angle.The dangerous angle of the overall structure of the platform is 0°,and the failure mode is that the first layer member breaks for the first time,and then the main string between the first and second layers continues to break until the platform is overturned.The self existence ability of each limit state of the derrick and the whole platform at different wind speeds is evaluated.The failure probability corresponding to the WLS,HLS and SDLS of the 51 m/s super typhoon platform: 0° derrick: 84.08%,64.49% and 50.34%;0° platform overall: 91.44%,63.09% and 43.50%;270° derrick: 98.76%,93.80% and 86.55%;270°platform overall: 73.73%,40.66% and 22.21%,the probability of collapse of the derrick under the super typhoon far exceeds the overall platform.Form a performance-based wind-resistant design method,propose threshold for dividing the performance level of different structures,the displacement angle threshold of the derrick structure: 1/200,1/50,1/30;the overall displacement threshold of the platform: H/600,H/400,H /125.