Centrifuge model tests on the bearing behavior of large-diameter rock-socketed pile group in valley area

Large-diameter rock-socketed pile groups are an effective method for distributing bridge and traffic loads in long-span bridges. Currently, the bearing behavior of large-diameter rock-socketed pile groups in valley areas remains insufficiently understood. In order to understand the bearing behavior of large diameter rock-socketed pile group in valley area, three centrifuge model tests were carried out to simulate the mechanical characteristics of pile group with different slope angle. The results indicated that pile groups shown linear load-settlement responses until the ultimate load, and the settlement of pier cap was positively correlated with slope angle. There are obvious differences in the load sharing of single piles, and the existence of the slope angle exacerbated the differences in load sharing for single piles. Moreover, the tendency of axis force-depth was similar, showing that the axis force of the large-diameter rock-socketed pile decreased modestly in the overburden layer, and decreased steeply in the rock-socketed layer. The slope angle reduces the shaft resistance of the overburden layer, which reduces the bearing capacity of the group pile, and this negative effect increases with the slope angle. Accordingly, the valuable results obtained from the centrifugal model tests to guide the design and construction of large diameter rock-socketed pile group in valley area.