LAUSR

The undrained shear strength of clay is important for deep-sea foundation design. T-bar penetrometer as a key tool has been widely used in laboratory and offshore site investigation. To obtain a continuous soil strength profile, it is necessary to apply shallow corrections before the penetrometer reaching the full-flow state. Meanwhile, the actual soil strength may be underestimated if the strain softening behavior is not considered. In this study, the process of T-bar penetration is analyzed for the soil with strain softening. The buoyancy effect on the bearing capacity factor is studied, which shown that the buoyancy mainly has an effect on the test soils with extremely low strength, but have little effect in the field tests. The characteristics of soil heave in the T-bar tests are analyzed to estimate soil sensitivities. To estimate the soil strength at shallow penetration depth, a relation to correct the T-bar bearing factors is built both on the soil with strain softening and no strain softening.