Research On Bearing Capacity Of Pipeline Repaired By Grouting Anchor Lining Method

The technology of grouting anchor lining method is a kind of pipeline repair method,also known as slurry lining method,which installs the quick pad in a new pipeline and fills the annular gap between the quick pad and the original pipeline by grouting,without earthwork excavation.At present,the technology of grouting anchor lining method is basically decided by the actual construction experience,lacking the design theory and calculation method of the system.Therefore,the design theory of the repairing pipeline with liner method is deeply studied in this paper.The research contents and conclusions are as follows:(1)Summarized the existing Trenchless Pipeline Repair Methods at home and abroad,discussed the applicability of different Trenchless Pipeline Repair methods,compared and analyzed the applicability,advantages and disadvantages of different methods.The existing design theory of Trenchless Pipeline Repair is studied,which provides a theoretical basis for the design and analysis of liner repair structure.(2)The technological principle,material and equipment as well as the corresponding inspection and acceptance criteria of the liner repair project are analyzed.The design content and calculation of the main parameters of the liner repair project are studied.The main loads and key parameters of the pipeline during operation are analyzed and calculated.The selection method of the wall thickness of the pipeline is discussed with emphasis on structural repair and semi-structural repair.The formula of the thickness of the complex lining is deduced,and the calculation and analysis are carried out according to the actual case.(3)Based on elasticity mechanics and pipeline repair codes at home and abroad,according to the difference of pipeline damage degree,the calculation model of repairing pipeline by liner method is deduced.According to the proposed calculation model,the bearing capacity of repaired pipeline and the stability of repaired pipeline are calculated through case analysis.In addition,the field test results and theoretical calculation results are compared and analyzed.It is found that they are in good agreement and the reliability of theoretical analysis is verified.In view of the phenomenon that the theoretical calculation value is generally lower than the experimental value,the main reason is that some parameters are conservative in the calculation process,and the effect of internal water pressure and vacuum pressure is not taken into account in the experiment process,and there are some errors with the actual conditions.(4)Using Abaqus finite element analysis software,the stress distribution on the old concrete pipe and grouting layer repaired by liner method was studied.The uniformly corroded concrete pipe,corroded perforated concrete pipe and concrete pipe with axial crack repaired by liner method were analyzed by finite element method.The stress and deformation of pipeline before and after repairing were calculated,and the finite element models with different repairing thickness were established.The influence of grouting thickness on repairing effect was further discussed.The reliability of repairing pipeline by liner method was verified,and the safe operation of repaired pipeline was ensured.