Centrifugal model tests on micro-pile-reinforced shallow foundation in layered soils

The centrifugal model tests are conducted on the micro-pile-reinforced and unreinforced shallow foundations buried in complex formation during vertical loading. The deformations of soil base and the foundation are observed and compared for the micro-pile reinforcement effects. The results show that the micro-piles significantly reduce the settlement of shallow foundations. The main scope of the micro-pile reinforcement is above a depth of 4 m in the silty clay layer. Under the reinforcement of the micro-piles, the settlement of the foundation is more regular and uniform, and the displacement change near the boundary layer between the clay layer and the silty clay layer is more gentle. The depth of the load influence zone decreases if the micro-piles are used, and the width of the influence area of the clay layer is reduced by a greater extent than that of the silty clay layer. The micro-piles suppress the transmission of loads to the lower strata and constrain the horizontal displacement of the soils, thus increase the bearing capacity of shallow foundation. The rules obtained from this study may provide reference for the application of micro-piles in practice.