为评估应变软化和应变率效应对四桩基础水平承载特性的影响,通过ABAQUS有限元软件,建立四桩基础二维平面应变模型,并在vumat用户子程序中定义软黏土不排水抗剪强度su随累积塑性剪切应变和最大剪切应变速率的变化关系,进而分析应变软化参数δrem、ξ95和应变率参数μ对四桩基础水平承载特性的影响。分析结果表明：四桩基础水平承载力会随着应变软化参数δrem、ξ95的减小而逐渐降低,其中δrem对水平承载力的影响较为显著;应变率参数μ与四桩基础水平承载力呈现线性正相关。最终,基于上述数值分析结果建立考虑应变软化和应变率效应的四桩基础水平承载力统一预测模型。
Abstract
In order to evaluate the influence of strain softening and strain rate effect on the horizontal bearing characteristics of the four-pile foundation, a two-dimensional plane tetrapod pile foundation model by ABAQUS is developed. The relationship between the change of the undrained shear strength su of soft clay with the cumulative plastic shear strain and the maximum shear strain rate is defined in the vumat user subroutine, and the effects of the strain softening parameters δrem, ξ95 and the strain rate parameter μ on the horizontal bearing characteristics of the four-pile foundation are analyzed. The analysis results show that the horizontal bearing capacity of the four-pile foundations decreases with the decrease of the strain softening parameters δrem and ξ95, among which δrem has a more significant effect on the horizontal bearing capacity; The strain rate parameter μ shows a linear positive correlation with the horizontal bearing capacity of the four-pile foundations. Finally, based on the study findings, an unified prediction model of the horizontal bearing capacity of four-pile foundations considering strain softening and strain rate effect is established.
关键词
海上风电 /
黏土 /
应变率 /
应变软化 /
水平承载力 /
四桩基础
Key words
offshore wind power /
clay /
strain rate /
strain softening /
horizontal bearing capacity /
four-pile foundation
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基金
国家自然科学基金青年项目（52008268）; 国家自然科学基金面上项目（52378357）; 辽宁省博士科研启动基金（2022-BS-195）; 教育部“春晖计划”合作科研项目（HZKY20220416）
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