Performance of Piled Footings in a Lightly Cemented Residual Soil Site

Piled footings are composite foundations that offer technical and economic advantages over traditional designs. This type of foundation combines the benefits of shallow and deep foundations into a unique structure. This paper investigates the behavior of piled footings supported on lightly bonded residual soil. Two full-scale load tests in a pile group and a piled footing were conducted at an experimental site, using geotechnical instrumentation to investigate the load-sharing between foundation elements. Numerical modeling was performed to verify the soil-structure interactions and deformation mechanisms during the loadings. The results show that piled footings are an efficient alternative to reduce settlements and increase the load capacity of the foundation system. The high initial stiffness from natural cementation in the residual soil ensures a great contribution of the footing’s base. The field instrumentation and numerical results demonstrated that the contact between the footing base and the soil reduces the mobilization of shaft friction by affecting the relative displacements in the soil surrounding the top of piles. Nevertheless, the outcomes indicate the feasibility of piled footings as an alternative for the foundation system of small and low-cost housing in developing countries with similar residual soils.