Effect of lattice leg on penetration resistance of spudcan foundations-Physical and numerical modeling

Abstract

To further address the effects of lattice leg on penetration resistance of spudcan foundations, centrifuge model tests are conducted in both single soil layer and layered soil deposits. The centrifuge model test results show that, in a single soil layer, increased vertical penetration resistance has been observed for spudcan footing with lattice leg. The magnitude of the increase varies with the opening and area ratios of the leg, with a smaller opening ratio and a larger area ratio tending to confer larger penetration resistance. For the dual soil layer with sand overlying clay, the spudcan without lattice leg shows an abrupt decrease in penetration resistance towards the lower part of the sand layer, which suggests severe punch-through failure. In contrast, the spudcan footing with full sleeve not only shows an increase in penetration resistance but the decrease in penetration resistance is significantly minimized. This suggests that upward sleeve may be useful in mitigating risk of punch-through in a manner similar to the downward skirt. Furthermore, an effective stress finite element method is used to investigate spudcan penetration, which is shown to gives a good prediction of the penetration behavior with lattice leg enclosed. © 2010 Taylor & Francis Group, London.