基于改进Burgers模型的海相软土剪切蠕变特性  

Shear creep characteristics of marine soft soil based on improved Burgers model

作　　者：郭培玺 虞子楠 GUO Pei-xi;YU Zi-nan(Xijing University,Xi’an 710123,China;Key Laboratory of Safety and Durability of Concrete Structures in Shaanxi Province,Xi’an 710123,China;College of Highway,Chang an University,Xi’an 710064,China)

机构地区：[1]西京学院,陕西西安710123 [2]陕西省混凝土结构安全与耐久性重点实验室,陕西西安710123 [3]长安大学公路学院,陕西西安710064

出　　处：《水运工程》2022年第3期157-162,192,共7页Port & Waterway Engineering

基　　金：国家重点基础研究发展计划(973计划)资助项目(2017YFD0800501)。

摘　　要：以珠三角地区某港口地基海相软土为例,分别开展固结排水和固结不排水三轴剪切蠕变试验,并结合剪切蠕变试验结果,在传统Burgers模型的基础上,引入一个非线性SP元件,串联后得到一个新的一维蠕变本构模型,并将其拓展为三维情形,利用改进模型拟合海相软土剪切蠕变曲线,并验证其正确性和合理性。结果表明,每一级加载瞬间海相软土均表现出瞬时弹性变形,随即表现出衰减和稳定蠕变阶段,最后一级加载海相软土发生加速蠕变;每一加载等级的不排水条件下的轴向应变量值和孔隙水压力均大于排水条件;海相软土的渗透性影响蠕变变形,弱渗透性条件更有利于蠕变变形的累积;改进Burgers模型拟合海相软土剪切蠕变曲线,吻合良好。Taking the marine soft soil of a port foundation in the Pearl River Delta as an example, we carry out the triaxial shear creep tests of consolidated drainage and consolidation undrained respectively. Based on the results of shear creep tests and the traditional Burgers model, we introduce a nonlinear SP element, obtain a new one-dimensional creep constitutive model after series connection, extend it to three-dimensional case, use the improved model to fit the shear creep curve of marine soft soil, and verify the rationality and correctness of the model. The results show that the marine soft soil shows instantaneous elastic deformation at each moment of loading, and then shows the stage of decay and stable creep, and the last stage of loading marine soft soil has accelerated creep. The axial strain and pore water pressure of each loading level are higher than these of drainage condition. The permeability of marine soft soil affects creep deformation, and the weak permeability condition is more conducive to the accumulation of creep deformation. The improved Burgers model is used to fit the shear creep curve of marine soft soil, which is in good agreement.

关 键 词：港口地基 海相软土 剪切蠕变 BURGERS模型 渗透性 

分 类 号：U655[交通运输工程—港口、海岸及近海工程]