Soil pressures on pile shaft due to spudcan penetration in clay

In order to analyze the soil pressures on the adjacent pile shaft during spudcan penetration, the CEL (coupled- Eulerian-Lagrangian) method is used to calculate the soil pressures, and the efficacy of the method is proved by comparison with a centrifugal model test. On this basis, the relationship between the soil-pile relative displacements and the soil pressures is analyzed. The results show that the soil pressures facing the spudcan increase with the soil-pile displacements: within 6 times the adjacent pile diameter below the mud surface, the maximum value along the pile increases with the depth, changing within the range of 3.5s_u~9.0s_u; and when the depth is more than 6 times the pile diameter, the maximum value tends to stabilize at about 9s_u. The soil pressures not facing the spudcan decrease with the soil-pile displacements, and the minimum value along the pile shaft is 1.5s_u ~2.0s_u. The resultant pressures increase with the soil-pile displacements: within 6 times the adjacent pile diameter below the mud surface, the ultimate soil pressure along the pile increases with the depth, and the changing range is 2.0s_u~7.5s_u; when it is deeper than 6 times the pile diameter, the ultimate soil pressure tends to stabilize at about 7.5s_u. In addition, the shear strength of clay and the spudcan-pile clearance have little influences on the relationship between the soil pressures and the relative displacements. And the relative displacements required to reach the ultimate soil pressure decrease from 0.3 to 0.1 times the pile diameter when the modulus increases from 100s_u to 300s_u.