摘要
考虑到真空联合堆载预压能够加快竖井地基固结速率,以及变荷载、变井阻、土体非线性特性、径竖向组合渗流和土体自重应力分布对竖井地基固结速率的影响,基于真空联合堆载预压固结模型,建立真空联合多级堆载下的竖井地基非线性固结模型.通过公式推导,建立了相应的控制方程组,运用有限差分法求得相应的数值解.最后通过与已有的解析解及工程实测值进行对比,验证数值解的正确性,并对不同条件下竖井地基固结性状进行深入分析.结果表明:竖井地基固结速率随变井阻参数的增大而减小,随着最终排水能力参数的增大而增大;当土体的压缩指数和渗透指数的比值一定时,竖井地基中前期的固结速率会随着两级荷载比值的增大而减小,中后期的固结速率会随着真空负压的增大而增大;当竖井打设深度与竖井影响区半径比值大于20时,竖向渗流对固结速率的影响可以忽略不计.
Considering the consolidation rate of shaft foundation accelerated by the vacuum combined surcharge preloading and the influences of multi-stage surcharge preloading,time-and depth-dependent well resistance,radial and vertical combined seepage flow,soil nonlinear characteristics and soil gravity stress distribution on the consolidation rate of the shaft foundation,based on the vacuum combined surcharge preloading model,the nonlinear consolidation model of shaft foundation under vacuum combined multi-stage surcharge was established.Through formula derivation,the corresponding control equation system was established,and the corresponding numerical solution was obtained by the finite difference method.By comparing with the existing analytical solutions and engineering measured values,the numerical solutions were verified,and the in-depth analysis of the consolidation characteristics of the shaft foundation under various conditions was conducted.The results show that the consolidation rate of the shaft foundation is decreased with the increasing of variable well resistance parameter and increased with the increasing of final drainage capacity parameter.When the ratio of the compression index to the permeability index of soil is constant,the rate of consolidation in the early stage of the shaft foundation is decreased with the increasing of the ratio of two-stage loads,and the rates of consolidation in the middle and later stages are increased with the increasing of vacuum negative pressure.When the ratio of shaft excavation depth to the radius of shaft influence zone is greater than 20,the influence of vertical seepage on the consolidation rate can be ignored.
作者
史蓝天
王路
SHI Lantian;WANG Lu(Faculty of Civil Engineering and Mechanics,Jiangsu University,Zhenjiang,Jiangsu 212013,China)
出处
《江苏大学学报(自然科学版)》
北大核心
2025年第5期595-603,共9页
Journal of Jiangsu University(Natural Science Edition)
基金
国家自然科学基金资助项目(72071097)。
关键词
竖井地基
变井阻
软土固结
变荷载
真空预压
非线性
vertical drain
variable well resistance
consolidation of soft soil
time-dependent loading
vacuum preloading
nonlinear
作者简介
史蓝天(1998-),男,江苏镇江人,硕士研究生(837074054@qq.com),主要从事竖井排水固结研究;通信作者:王路(1986-),男,江苏宿迁人,博士,副教授(luwang@ujs.edu.cn),主要从事工程建造与管理研究.
