Undrained Shear Properties of Shallow Clayey-Silty Sediments in the Shenhu Area of South China Sea

Suction piles are used to ensure wellhead stability during natural gas hydrate production in the Shenhu area of South China Sea (SCS). Undrained shear properties clayey-silty sediments play a critical role analysis suction piles. However, it has not been fully studied. This study conducts series undrained triaxial tests on shallow SCS, and stress–strain curves under different overconsolidation ratio (OCR) conditions obtained. OCR effects discussed, model predict pore pressure coefficient at failure is proposed. Results show that isotropic compression index 0.175, swelling 0.029. The strength proportional effective confining pressure, proportionality 0.42 for normally consolidated specimens, while OC specimens nonlinearly increases with OCRs increasing. proposed aptly predicts SCS OCRs.