A new type of expand-footed tubular pile constructed by static driving

As a new type of pile, expand-footed tubular pile consists of pre-stressed concrete tubular pile and enlarged concrete foot formed by extruding concrete. Its construction technique, load transfer characteristic, laboratory model experiment, in-site test and application in a project are introduced here. It is found that by statically driving some concret into tubular pile bottom, an ellipsoidal foot is shaped, the pile vertical capacity increases evidently, the soil near foot has been squeezed more dense. The pile is proved with the property of higher bearing capacity, smaller settlement, more economic and environment protection compared with ordinary close bottom tubular pile. It is valuable to be spread in use.