基于接触面统计损伤模型的吸力锚排水上拔承载力分析

Analysis of Drained Uplift Capacity of Suction Anchors Based on a Statistical Damage Model of Clay-Structure Interface

摘要

为分析软黏土海床中吸力锚基础的排水上拔承载性能,首先结合损伤力学原理和 Mohr-Coulomb 强度准则,建立基于 Weibull 分布函数的钢结构-饱和黏土接触面统计损伤模型,进而提出吸力锚排水上拔承载力简化剪切位移算法。 通过开展一系列钢结构-饱和黏土接触面环剪试验确定模型参数,并验证模型的准确性。 分析表明:钢结构-饱和黏土接触面的排水剪切呈现显著的应变软化行为,吸力锚上拔过程中锚-土接触面出现应力重分布,界面发生渐进破坏;相同锚壁面积条件下,增加吸力锚长度相较于增加锚径更有利于提高吸力锚排水上拔承载力;应力水平是影响锚-土接触面抗剪强度的关键因素,工程中优先选择土体重度较大的地基,可有效提升吸力锚的抗拔性能。

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.

关键词

吸力锚 / 结构-土接触面 / 界面环剪 / 上拔承载力

Key words

suction anchor / clay-structure interface / interface ring shear / uplift bearing capacity

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基金资助

国家自然科学基金资助项目(52308378)

江苏省自然科学基金资助项目(BK20240501)

扬州市自然科学基金资助项目(YZ2024190)

江苏省高等学校基础科学(自然科学)研究面上项目(22KJB560034)