Theoretical Study On Trenchless Pipeline Replacement Technology By Static Pipe Bursting

As the most widely used trenchless pipeline replacement technology at home and abroad,the static pipe bursting method can ensure the equal diameter or expanding diameter replacement of buried pipeline under the premise of minimum excavation,so as to meet the low cost and high efficiency of construction to the greatest extent.However,the relevant technical theory of this method is not perfect at present.For this reason,this paper has carried out the following research in order to provide some reference for the actual construction:(1)This paper systematically summarizes the process principle,applicable characteristics,key technology and specific construction process of the static pipe bursting method,lists the current mainstream construction equipment at home and abroad,and sorts out the relevant technical standards that can be relied on at home and abroad.(2)The principle and deficiency of Ariaratnam-Hahn model are analyzed.Based on this derivation,a new model for estimating the pulling force of static pipe bursting is put forward.The validity and applicability of the model are proved by examples and comparison,and several groups of analysis and calculation are carried out assuming different conditions.The influence rules of two main parameters on the estimated pulling force are obtained.(3)Based on the ABAQUS finite element analysis platform,the construction contrast model of static pipe bursting with different buried depth,expanding degree and stratum soil conditions is constructed.Based on the results of numerical simulation,the distribution and evolution of the displacement of the stratum caused by the construction of static pipe bursting are analyzed in detail.Based on the classical Peck formula and its related theory which are often used in the calculation of stratum settlement,the static model is derived and put forward.By comparing the calculated value of the model with the numerical simulation results one by one,the rationality and accuracy of the modified model are verified.(4)On the basis of the research of the finite element simulation,the paper further constructs several groups of comparison models of adjacent pipelines with different spatial positions,analyzes the corresponding numerical simulation results,and reveals the influence on stress and deformation development of adjacent pipelines in the process of static pipe bursting construction.Then,by comparing the results of these models with that without adjacent pipelines,the phenomenon and mechanism of the change of stratum displacement distribution caused by different adjacent pipelines are discussed.