Mechanical Characteristic Analysis Of Buried Drainage Pipes After Polymer Grouting Trenchless Rehabilitation

Polymer grouting technology has been widely used for repairing leakage and subsidence of buried pipeline,but the research on calculation theory after pipeline repairing is relatively insufficient.Therefore,the Winkler model and Vlazov model was established to analyse pipe-soil-polymer interaction based on elastoplastic theory,and then applies the above models to the static and dynamic response analysis of normal pipelines,void pipelines and polymer grouting repair pipelines.At the same time,the calculated value is compared with the field test value,and the force and deformation characteristics of the polymer grouting repair of the buried drainage pipeline are studied.The main research contents are as follows:(1)By summarizing and summarizing the relevant research on pipe-soil interaction of buried pipelines,the Winkler model and Vlazov model of pipe-soilpolymer interaction analysis are established based on the elastoplastic theory,and the polymer grouting repair pipe-soil-is derived.Calculation formula for polymer interaction.(2)Based on the transfer matrix method,use the above-established pipe-soilpolymer interaction analysis Winkler model and Vlazov model to simulate the pipesoil-polymer interaction,compile MATLAB calculation program,and inject the polymer into the underground pipeline.The force and deformation before and after the grout repair are calculated.The calculated values of radial deformation and hoop bending moment calculated by the Winkler model and the Vlazov model considering the pipe-soil-polymer interaction are basically consistent with the experimental values,and the model can be used for calculation and analysis of pipelines.(3)Refer to the field test results and compare with the model calculation results to discuss the accuracy and rationality of the Winkler model and the Vlazov model,and carry out the research on the force and deformation characteristics of the pipeline after the vented polymer grouting repair.The working conditions include Pipeline depth,load concentration,elastic modulus of backfill,pipe wall thickness,etc.After being repaired by polymer grouting,the radial deformation,axial internal force and hoop bending moment of the pipeline are close to the normal pipeline,indicating that the polymer grouting has a better function of repairing the pipeline.(4)Based on the elastic foundation beam theory,establish the longitudinal and lateral vibration model of the polymer repaired pipeline considering the traveling wave effect.The seismic input adopts artificially generated random seismic waves,and then the pipeline vibration equation is solved.Seismic response analysis under three conditions of normal,void and polymer grouting repair.After considering the traveling wave effect,the reaction of each measurement point of the pipeline has obvious phase characteristics.Under the traveling wave effect,the peak displacement of the pipeline after emptied will increase by 100%～300% compared with the normal situation.There is a 20%～30% difference between the amount of deformation and the normal situation,indicating that the bottom vent will have a great impact on the deformation of the pipeline,and the polymer repair can basically restore the mechanical properties of the pipeline to the normal level.