Axial Behavior of Buried Rehabilitated Pipe in Liquefaction Ground

Abstract

In Japan, the total length of aging irrigation pipeline increases and requires a lot of repair work. As part of the repair work for an aging pipeline, pipe rehabilitation has been used. In this method, the inner pipe (rehabilitated pipe) is inserted into the outer aging pipe. Studies on the axial behavior of the rehabilitated pipe are not readily conducted although the influence of the outer aging pipe on the cross-section behavior of the inner pipe is evaluated by model tests, centrifuge tests, and FEM analyses. In this study, shaking table tests are conducted to verify the dynamic behavior along the axial direction of the inner pipe used for the method. To model inner pipes, polyvinyl chloride (PVC) and polyethylene (PE) pipe, which are 3040 mm in length and 140 mm in diameter, are used. To model outer pipes, different types of concrete pipes in length are used. Test results indicate that the amplitude of the bending strain of the PVC pipe with the outer pipe is large shortly after the pipe was moved horizontally due to liquefaction. In addition, the gradient of the bending strain increment to the horizontal displacement increment of the pipe end increases in proportion to the length of the outer pipe.