Study On The Jacking Force Induced By Linear And Curved Pipe Jacking Construction

As a modern laying pipe jacking technics, the pipe jacking construction technology has much advantage. With the environment getting more attention, the use of not-dig pipe jacking technology has become more extensive. However, being sluggish in the theory and immature in the construction, the application of the pipe jacking construction technology is affected.This dissertation based on the summary of existing theory testing fruit and computed approaches, the behavior of jacking force of linear curved and long pipe jacking has been analyzed during construction. More reasonable method for jacking force has been raised. The theoretical computing formulae of linear and curved pipe jacking have been deduced; then an experienced formula of linear pipe jacking is presented. At last, the influence domino effect to pipe jacking and soil has been analyzed by using FEM during construction. The main contents are as follows:1 Based on the existing formulae of jacking force, the influence factors for linear pipe jacking have been analyzed. Considering the soil arch domino, the formula of linear pipe jacking has been deduced. On the basis of the case of sewage disposal factory, experienced formula of friction has been obtained by using subsection function and then experienced formula of jacking force is acquired for this area. The results of computing analysis are contrast to the experimental dada in the form of figure.2 The mechanics behavior for cuneiform ringer and pillow the cell curved pipe jacking technique has been analyzed, the incremental formula of soil resistance is obtained. The arch domino of steady soil is concerned, the incremental formula of cuneiform ringer and pillow technique has been deduced. Combining with results of test, the theoretic analysis is contrast to the experimental dada in the form of figure.What's more, the computed method of axial stress of pipe jacking is presented in the form of figure and table during the curved pipe jacking construction. The stress formulae for the center of pipe jacking and the joint have been summarized.3 The influence domino effect for pipe and soil caused by construction has been analyzed by using FEM. Be based upon the deformation harmonious principle for pipe jacking and soil, the stress of soil and internal force of pipe jacking have been attained. The relationship between elasticity modulus diameter of pipe jacking, covered height and internal force of pipe jacking and soil stress are discussed.4 From the technology of reducing friction slurry and the relay jacks, the jacking force of long pipe jacking has been analyzed. On the side, a suggestion for the design of the relay jacks has been put forward and the development of long pipe jacking has been expected.