摘要
文章基于连续排水边界,利用Merchant模型描述土体的黏弹性,并结合Terzaghi一维固结理论建立荷载作用下双层地基一维固结模型。通过边界转换法和Laplace变换推导频域内控制方程的解析解,利用Stehfest数值逆变换法得到时域内土体超孔隙水压力和沉降的半解析解,并依次给出沉降和孔隙水压力定义下2种固结度的半解析表达式。基于已有的单层黏弹性解,退化分析验证了解法的正确性。最后,通过算例分析探究2种定义下固结度的区别以及界面参数、土体物理力学性质和水文地质参数对地基固结过程的影响。结果表明:相较于已有的弹性解答,黏弹性解解释了土体变形总是滞后于超孔隙水压力消散的现象;超孔隙水压力的消散速率随界面参数的增大而加快,黏滞系数越小且渗透系数越大时土体固结越快,但黏滞系数对固结的影响主要在中后期,渗透系数的影响则主要体现在前中期。该研究结果可为软土地基的沉降预测提供一定的理论参考。
Based on the continuous drainage boundary,combined with Terzaghi’s one-dimensional consolidation theory,the one-dimensional consolidation model for double-layered foundation under external loads is established,in which the Merchant rheological model is used to simulate the soil viscoelasticity.The analytical solutions of the governing equation in the frequency domain are derived by applying the boundary transformation method and Laplace transform,and the semi-analytical solutions of excess pore water pressure in soil element and total settlement of foundation in the time domain are calculated by using the Stehfest numerical inversion method.The semi-analytical expressions for the two kinds of consolidation degrees defined by settlement and pore water pressure are given,respectively.Subsequently,the validity and correctness of the proposed solutions are verified by comparison with the degradation results of the present method and the existing viscoelastic solutions of single foundation.Finally,the detailed parametric analyses are conducted to reveal the difference between the two kinds of average consolidation degrees and the influences of interface parameters,physical and mechanical properties of the soil and hydrogeological parameters on the consolidation process of foundation.The results show that the proposed viscoelastic solutions,compared with the existing elastic solutions,illustrate the phenomenon that soil deformation always lags behind the dissipation of excess pore water pressure.Moreover,the dissipation rate of excess pore water pressure accelerates with the increment of interface parameters.The smaller the viscosity coefficient and the larger the permeability coefficient,the faster the soil consolidation,but the influence of viscosity coefficient on the consolidation is mainly in the middle and late stage of the consolidation process,while the influence of permeability coefficient is mainly reflected in the early and middle stage.The research conclusion of this paper can provide theoretical reference for the settlement prediction of soft soil foundation.
作者
邱昌虎
蒋明杰
杨伟涛
梅国雄
QIU Changhu;JIANG Mingjie;YANG Weitao;MEI Guoxiong(School of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;Ocean College,Zhejiang University,Zhoushan 316021,China)
出处
《合肥工业大学学报(自然科学版)》
北大核心
2025年第2期260-266,共7页
Journal of Hefei University of Technology:Natural Science
基金
国家自然科学基金资助项目(52108309,52178321)
广西自然科学基金资助项目(2021GXNSFBA196091)。
关键词
连续排水边界
双层地基
固结
黏弹性
半解析解
continuous drainage boundary
double-layered foundation
consolidation
viscoelasticity
semi-analytical solution
