Abstract:To analyze the drained uplift bearing capacity of suction anchors in soft clay seabed, a statistical damage model based on the Weibull distribution function was established for the saturated clay-structure interface, integrating the principles of damage mechanics and the Mohr-Coulomb strength criterion. Subsequently, a simplified shear displacement method for the uplift bearing capacity of suction anchors was proposed. A series of ring shear tests of saturated clay-steel interface were conducted to determine the model parameters and validate the accuracy of the model. It is found that the drained shear of saturated clay-steel interface exhibits significant strain softening characteristics. During the uplift process of suction anchors, stress redistribution occurs at the clay-anchor interface, leading to its progressive failure. For the same area of anchor wall, increasing the anchor length is more beneficial for enhancing the drained uplift bearing capacity of suction anchors compared to increasing the anchor diameter. Additionally, the stress level is a critical factor influencing the shear strength of clay-anchor interface. In practice, prioritizing sites with higher soil density can effectively improve the uplift bearing performance under drainage conditions.