摘要
引入Koeller定义的弹壶元件修正Merchant模型探究砂井地基的流变固结机理,以此描述土骨架的黏弹性变形行为.引入非牛顿指数渗流模型描述固结过程中的非Darcy渗流,在自由应变假定下修正了Barron的理想砂井地基固结方程,用隐式有限差分法进行数值求解.通过与Barron砂井固结理论的对比,验证了有限差分算法的有效性,分析了非牛顿指数渗流模型参数及分数阶Merchant流变模型参数对砂井地基径向固结过程的影响.结果表明,砂井地基中的孔压消散随着Kelvin体弹性模量的增大而加快;分数导数阶数和黏滞系数在不同的固结阶段对孔压消散的影响规律不同.相比Darcy渗流,非牛顿指数渗流会延缓砂井地基中的孔压消散.
To further investigate into the rheological consolidation mechanism of ground with sand drains,the Koeller spring-pot element was introduced to replace the Newton dashpot element of the classical Merchant model,and the modified Merchant model was used to describe the rheological constitutive relationship of saturated clay.The flow model with the non-Newtonian index was employed to describe the non-Darcy flow in the process of rheological consolidation and,accordingly,Barron’s consolidation theory for clayey ground with vertical ideal sand drains was modified under the assumption that the vertical strains develop freely,and the numerical solution was conducted by the implicit finite difference method.In order to verify its validity,the numerical solutions by the present method were compared with the results of Barron’s consolidation theory.The effects of the parameters of non-Newtonian index and fractional-order Merchant’s model on the rheological consolidation of ground with sand drains were investigated.Numerical results indicated that the dissipation of pore water pressure in the ideal sand-drained ground accelerated with the increase of the Kelvin’s elastic modulus.The fractional order and the viscosity coefficient have different effects on the dissipation of pore pressure in different consolidation stages.
作者
刘忠玉
崔鹏陆
范智铖
宁秉正
张家超
Liu Zhong-yu;Cui Peng-lu;Fan Zhi-cheng;Ning Bing-zheng;Zhang Jia-chao(School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,China)
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
2020年第4期545-552,共8页
Journal of Lanzhou University(Natural Sciences)
基金
国家自然科学基金项目(51578511)
关键词
砂井地基
固结
黏弹性
分数阶导数
非达西渗流
有限差分法
sand-drained ground
consolidation
visco-elasticity
fractional derivative
non-Darcy flow
finite difference method
