采用基于Tresca屈服准则的理想弹塑性模型,结合建议的软土刚度弱化模型,通过编制USDFID子程序,建立描述软土中吸力桶基础循环弱化过程的数值分析方法;针对张紧式吸力桶循环加载模型试验开展三维数值模拟,验证建立的数值方法的合理性,同时分析吸力桶基础的循环弱化承载特性。研究结果表明,该方法能预测吸力桶基础在软黏土中的循环变形和承载能力,描述其荷载-位移曲线的非线性滞回及循环累积特性。增加吸力桶的直径或长度均能一定程度上降低基础刚度的弱化,且在用钢量相同的条件下,相较于增加桶径,增加桶长对循环承载力的提升更为显著。
Abstract
A numerical analysis method describing the cyclic degradation for suction bucket in soft soil is developed by employing a perfect elastic-plastic soil model with Tresca yield criterion and the proposed stiffness degradation model of soft clay. The USDFID subroutine is encoded to realize this method. In order to verify the rationality of the numerical method, the three-dimensional numerical simulation is performed for the cyclic loading model test of the tensioned suction bucket foundation. In addition, bearing characteristics of the suction bucket foundation considering the cyclic degradation is also analyzed. Research results show that the numerical method can simulate the cyclic deformation process of suction buckets in soft clays, and predict the nonlinear hysteresis and cyclic accumulation of the load-displacement curves, as well as predict the cyclic bearing capacity of buckets. Increasing the diameter or length of the suction bucket can reduce the degradation of the foundation stiffness to a certain extent. Under the condition of the same steel consumption, increasing the length can improve the cyclic bearing capacity more significantly than increasing the diameter.
关键词
海上风电 /
黏土 /
循环荷载 /
循环弱化 /
吸力桶
Key words
offshore wind turbines /
clay /
cyclic loads /
cyclic degradation /
suction buckets
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基金
国家自然科学基金（52108334）; 中国电建集团华东勘测设计研究院有限公司科技项目（KY2020-KC-08-01-2021）; 天津市科技支撑计划重点项目（19YFZCSN01180）
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