Analysis of Combined Pile Raft Foundations Based on a Static Load Test

Combined pile raft foundations (CPRF) take into account the synergy of a raft with a group of piles in transferring the load to the ground. In many ground conditions, such foundations are optimal in both utilitarian and economic terms. Based on a literature review, it can be concluded that, despite the numerous extant calculation methods for the analysis of piled raft foundations, there is lack of research related to the possibility of using a load-settlement curve from a static pile test in the full range, in order to analyse the load-settlement curve of a pile working in a group under the raft. Furthermore, the current trend in the design of pile foundations, based on the static load test databases, encourages the formulation of methods using the results of the static pile test. These methods allow for analyses closer to the physical model. In this paper, the above research postulate was answered, formulating a mathematical model in which a particular emphasis was placed on the actual work of a single pile in the ground, taking into account the interaction among raft, piles and subsoil. The developed mathematical model was verified on the basis of the results of field research. For this purpose, the results of settlement of two tanks were used.