Field investigation of the performance of composite foundations reinforced by DCM-bored piles under lateral loads

The DCM-bored pile (DCM-BP) is a new kind of composite foundation formed by inserting a core-bored pile into a deep cement mixing (DCM) column socket, and the DCM-BP has only been used in a few projects to date. Unlike the conventional bored pile (CBP), the performance of the DCM-BP is enhanced by the surrounding cement-soil materials, which should result in a large change compared to that of the CBP. In this paper, a series of full-scale load tests on the DCM-BP were conducted to investigate the performance of the DCM-BP under lateral loads compared with that of the CBP. The lateral bearing characteristics of the DCM-BP and its advantages are presented in this study. Based on the test results, the DCM-BP displays a greater bearing capacity than that of the CBP, with much smaller lateral displacement under the same lateral load. Comparisons of the bending moments and lateral resistances of the DCM-BP and CBP were also analysed in detail. It is concluded that the DCM-BP has considerable advantages over the CBP because the DCM-BP improves the surrounding lateral resistance and enhances the performance of the core bored pile.