Abstract
A caisson type foundation is generally used for power transmission towers in mountainous areas. The leg of the tower, which is a steel pipe with ribs, is embedded in the cylindrical concrete structure as an anchor. Some experiments have been conducted by pulling out the anchor for investigating the failure mode and ultimate capacity. It was found that the failure mode was the splitting failure with cracks propagating from the pipe rib.
This paper describes the simulation of the behavior of the concrete cylinder with pullout anchors. It is impossible to simulate splitting cracks by a pure axial symmetric geometry. Therefore, a quasi 3-dimensional analysis using an axial symmetric geometry with the smeared crack element and the non-linear constitutive model in the circumferential direction based on fracture mechanics is carried out. The results of the simulations show the same failure mode and load-displacement relationship compared with experimental results. Some real size foundations, having a diameter of three meters, are also computed by the same numerical method. From the results of the analysis, it is found that the bearing capacity has a size effect.
