Bearing capacity tests and settlement calculation method of plastic tube cast-in-place concrete pile

The plastic tube cast-in-place concrete pile (TC pile), which is suitable for soft ground treatment, is comprised of pre-driven plastic tube filled with concrete, which has the advantages of high bearing capacity, fast construction speed and reliable pile quality etc. According to the model and in-situ tests on bearing capacity of TC piles, the working behaviors of TC piles are investigated. Taking into account the pile-soil settlement difference of rigid pile composite foundation under embankment load, the additional stresses generated by pile groups and foundation soils are separately computed by using the Mindlin stress solution and the Boussinesq solution. The two kinds of stresses are added together, and the settlement of composite foundation is calculated by using the layer-wise summation method. The results show that the bearing capacity ofTC piles exhibits obvious, time-dependent behaviors, however, there are significantly different bearing behaviors in different intermissions, and the calculated results of settlements of TC piles agree well with the measured data.