Based on experiment and simulation to evaluate the quality of large diameter concrete drain-pipe by jacking method

The large diameter reinforced concrete drain-pipe were applied in a underground drain-pipe jacking engineering. The inside and outside diameter of the drain-pipe are 3.5 m and 4.2 m respectively. The weight is 26000 kg, and jacking distance is 640 m. The nondestructive testing technology and three-edge bearing test were used to evaluate quality of the two large diameter concrete drain-pipe which selected randomly in engineering. The load-displacement curves and load-strain curves of drain-pipe were obtained, the global and local deformation laws of drain-pipe were analyzed through static test. The finite element model was established by ABAQUS, and the test results and simulation results were compared. The results of comparison show that the displacement of each measuring point increases with increasing load, and both of the two drain-pipe show well overall performance, and the well overall performance was shown in both of the two drain-pipe. The maximum displacement and strain were measured at the top of the drain-pipe, and the cracks are observed at the sidewall and bottom of drain-pipe. The load-displacement curves from simulation results is in well agree with the load-displacement curves from test results. It means that there is a good accuracy of the calculation results with the finite element model, which could be used as the basis for the corresponding research. Cracking load values under three-edge bearing test (the load value when the width of crack reaches 0.20 mm) of the two drain-pipe are 325 kN/m and 324 kN/m, respectively. And both drain-pipe meet the Chinese national standard, which the large diameter reinforced concrete drain-pipe could be used in actual engineering.