STUDY ON ANCHORING CAPACITY OF AN ANCHOR EMBEDDED IN A CONCRETE COLUMN CONFINED BY A STEEL PIPE

Abstract

Transmission tower legs are usually embedded in concrete column foundations. Concrete columns are confined by steel pipes to shorten the anchoring length by increasing the anchoring capacity. The anchoring capacity is greatly increased in the experiment. The reason why the anchoring capacity is increased is that the confined steel resists to the failure when radial splitting cracks occur in the concrete body. Two types of failure mode in the experiment were observed: One was where the encasing pipe yielded, and another was where a tower leg was pulled out from the concrete body. Based on the experiment, a method to predict the ultimate capacity of two failure mode is proposed.