Mechanical Analysis And Device Research On Grouted Clamps Of Damaged Structure Of Offshore Platforms

This paper is based on the project of the research of the clamp's strengthening technology of the platform's underwater structure.This project is authorized by the China National Offshore Oil Corporation and its purpose is to develop the strengthening structure of the ocean platform's underwater jacket which is used to strengthen the jacket's fragile points and damaged structure.This paper can provide technical support for the strengthening area of the civil ocean platform.Through the study of the clamp's strengthening technology and the typical strengthening structure of clamp,combined with the status of the underwater clamp's strengthen technology both in civil and abroad,this paper designed the general planning of the structure of grouted clamp which meet the requirements of clamp fixing and node strengthening.This paper also presented experimental program of mechanical properties of the grout and sealing of grouted clamp for clamp design.Combined with the structural forms of grouted clamp,the static strength of grouted clamp was analyzed and calculated in this paper.According to the underwater working conditions,theoretical buckling analysis was done under uniform external pressure and uniform axial compression for jacket before and after installing grout clamp and ten modal finite element buckling analysis was done for jacket before and after installing grout clamp with the software of ANSYS.The reliability of damaged pipeline was also analyzed and compared with the reliability of the damage pipeline installed with clamp.The overall structure of the clamp was designed in this paper,it includes the main mechanical structure of the clamp,hydraulic telescopic device and locking device,they achieved the goal of the automation of the clamp's closed and locked process.This paper used ABAQUS to analyze the ring and did experiment about the ratio of grout,and it selected a ring which is suitable in material and size and the best program of the ratio of grout.Prototypes of grout clamp were processed according to the design.And the experiments of mechanical properties of the grout and sealing of grouted clamp were carried out combined with experimental design.Thus the experiments verified the sealing properties and mechanical properties of grout clamp and ensured the safety and reliability of offshore platforms.