The composition, characteristics, construction equipment, construction process, and quality inspection method of cast-in-place concrete piles (TC piles), with singlewall corrugated PVC plastic tubes used in the construction process, are introduced. In combination with the soft foundation project of the Lianshi-Hangzhou section of the Shen-Jia-Hu-Hang Expressway reinforced by TC piles, the distribution and variation of the soil stress on the top of pile caps, and that between and under pile caps were compared and analyzed based on observations by embedded earth pressure cells and rebar stress meters. Variation curves of the pilesoil stress ratio and load sharing ratio against the filled load were obtained. The results show that the embankment load is gradually transferred to TC piles, and the pilesoil stress ratio increases first and then decreases as the height of embankment is increased. During the measurement period, the pilesoil stress ratio and load sharing ratio of TC piles tend to increase.