2018 Volume 13 Issue 1 Pages 41-59
The ground reinforcing pile used in this experiment composed of the soil column and the nodular thin steel pile which had significant different elastic modulus and yielding strain. In this paper, the vertical bearing properties and composite effects were considered by the axial force of the static axial compressive load test results of single ground reinforcing pile. The composite effects of the ground reinforcing pile could be considered by the axial stiffness ratio and the deformation of the composed materials. And the load which sheared with soil cement column and nodular thin steel pipe depended on the axial stiffness, then the yield of the ground reinforcing pile was defined by the yield strain of the thin steel pipe. In the composition with the soil cement column and the thin steel pipe, the axial stiffness ratio over 1 was not profitable because the compressive capacity of the column was over to the compressive capacity of the thin steel pipe. On the other hand, when the ratio fell below 0.1, the compressive capacity of the thin steel pipe became equal to the compressive capacity of the ground reinforcing pile because the value of the compressive capacity of the column approached 0. The column reinforced with the nodular thin steel pipe having the sufficient punching capacity supported the axial force, the ground reinforcing pile was possible to efficiently obtain the vertical bearing capacity of the ground in the depth direction. Furthermore, when the compressive strength of the column was especially small, the compressive capacity of the ground reinforcing pile was improved compared with that of the column alone. The ratio of the limited value of the test result to the value calculated by the allowable stress design method was greater than the safety factor.
