| Underground pipeline in-situ curing repair technology refers to the use of water pressure or air pressure to turn the soft liner impregnated with resin to the pipeline to be repaired without ground excavation,and form a higher-strength lining through curing.The old pipeline forms a composite pipeline to achieve the purpose of repairing a technology.For the calculation of the strength of composite pipes,there is still a lack of corresponding theories in China.Based on the management theory of combined thick-wall circles,this paper uses the combined form of composite pipes to study the strength calculation method of composite pipes,and draws the following conclusions:(1)Statistics and analysis of the research results of domestic and foreign scholars on the construction technology,strength theory and numerical simulation of CIPP pipeline repair technology,and pointed out the current problems and research directions in the current CIPP repair technology.(2)Based on the failure criterion of fracture strength,the strength failure theory model of the lined pipe is established;the stability bearing theory of the liner pipe is established based on the Cheney buckling model,and the bearing capacity formula is derived.(3)The strength calculation model of the lining pipe under the uneven thickness defect was studied,and it was verified by ABAQUS numerical simulation,and the influence of the uneven thickness defect on the strength of the pipe lining after repair was analyzed.(4)Based on the theory of combined thick-wall circle management,a composite pipe strength calculation model was established,the stress and strain conditions of the composite pipe during the load application process were analyzed,and the calculation formula for the strength of the composite pipe was deduced,which was verified by numerical simulation.The correctness of the compound strength calculation formula. |
