Abstract: The bearing behaviors of pile in calcareous soil foundation were studied by model test. Silica sand was also tested for comparison. Results reveal that the bearing behaviors of single pile in calcareous sand are different with those in silica sand. The bearing capacity of end-open pipe pile hardly differs from that of end-closed pipe pile. But in the presence of the same relative compaction, the bearing capacity of end-closed pipe pile in calcareous sand is much lower than that in silica sand. Moreover, in calcareous sand, the soil at pile’s endpoint undertakes most of the loads, and the axial force on the upper part of the pile has no big difference with that on the lower part. The greater the soil compactness, the more the ratio of load sharing by pile’s axial force. In silica sand, the axial force of pile reduces rapidly along the depth direction, and the rate of decay grows with the increase of depth. The side friction of pile in silica sand is larger than that in calcareous soils. The side friction of pile in calcareous sand distributes in a parabola shape, which is similar with that in silica sand. In calcareous sand, the side friction resistance of pile does not increase with the increase of relative compactness; whereas in silica sand, the increase is remarkable.

Key words: calcareous sand, model test, bearing capacity, side frictional resistance, grain crushing