饱和孔隙-裂隙黏土双层地基的一维固结分析

doi:10.16183/j.cnki.jsjtu.2021.019

摘要/Abstract

摘要：

为研究双孔结构饱和黏土双层地基的一维固结特性,在一维完全侧限条件下根据混合物理论建立了饱和孔隙-裂隙介质的固结控制方程.采用Fortran语言编制了饱和孔隙-裂隙黏土一维固结的有限元程序,利用单层地基研究成果验证本文模型和程序的正确性.运用有限元程序分析压缩模量、渗透系数及土层厚度等因素对饱和孔隙-裂隙黏土双层地基固结特性的影响.结果表明:增大上层较软土的压缩模量和渗透系数能更显著地加快地基的固结速率;裂隙和孔隙中的超孔压具有不同的消散规律,地基底部孔隙超孔压的消散滞后于裂隙超孔压,滞后效应随上层土渗透系数而增大.对于饱和孔隙-裂隙黏土双层地基,改良上层较软孔隙-裂隙黏土性质可较好地改善整个地基的固结特性.

关键词: 双层地基, 一维固结, 饱和孔隙-裂隙黏土, 混合物理论

Abstract:

In order to study the one-dimensional (1-D) consolidation behavior of double-layered saturated porous-fissured clay foundation, the governing consolidation equations of saturated porous-fissured media were developed based on the mixture theory under the condition of one-dimensional complete confinement. The finite element program for 1-D consolidation of saturated porous-fissured clay was compiled by Fortran language, and the results of single-layered foundation research were used to verify the correctness of this model and program. The influences of compression modulus, permeability coefficient, and soil thickness on the consolidation behavior of double-layered saturated porous-fissured clay foundation were analyzed by using the finite element program. The results show that the consolidation rate of the foundation can be significantly accelerated by increasing the compression modulus and permeability coefficient of the softer topsoil, and the dissipation laws of excess pore water pressure and excess fissure water pressure were different. The dissipation of excess pore water pressure at the base of the foundation would lag behind that of excess fissure water pressure, and the lag would increase with the increase of the permeability coefficient of topsoil. For double-layered saturated porous-fissured clay foundation, improving the softer porous-fissured clay properties of the upper layer can better improve the consolidation behavior of the foundation.

Key words: double-layered foundation, one-dimensional (1-D) consolidation, saturated porous-fissured clay, mixture theory

中图分类号:

TU43

胡亚元, 王啊强. 饱和孔隙-裂隙黏土双层地基的一维固结分析[J]. 上海交通大学学报, 2022, 56(4): 443-453.

HU Yayuan, WANG Aqiang. Analysis of 1-D Consolidation of Double-Layered Saturated Porous-Fissured Clay Foundation[J]. Journal of Shanghai Jiao Tong University, 2022, 56(4): 443-453.

图/表 11

图1

图2

图3

图4

表1

饱和孔隙-裂隙黏土双层地基模型计算参数[3, 15, 20]

土层	E_s/MPa	E_r/MPa	k_F_z×10⁶/(m·s^-1)	k_P_z×10¹⁰/(m·s^-1)	φ^F	φ^P	γ_w/(kN·m^-3)	$α -$ /m^-2
上土层	1.5	2.5	2.47	6.18	0.05	0.4	10.0	10.0
下土层	5.0	8.33	2.47	6.18	0.05	0.4	10.0	10.0

表1

表2

图5

表3

图6

图7

图8

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