真空堆载预压联合电渗竖向排水地基非线性固结解析解  

Nonlinear analytical solutions for vertical drainage consolidation of foundations under vacuum-surcharge preloading combined with electroosmosis

作　　者：黄鹏华 王柳江[1] 刘斯宏[1] 沈超敏[1] 鲁洋[1] HUANG Penghua;WANG Liujiang;LIU Sihong;SHEN Chaomin;LU Yang(College of Water Conservancy and Hydropower,Hohai University,Nanjing,Jiangsu 210098,China)

机构地区：[1]河海大学水利水电学院,江苏南京210098

出　　处：《岩石力学与工程学报》2021年第1期206-216,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：中央高校基本科研业务费(2019B11214);国家自然科学基金青年基金资助项目(51509077);江苏省研究生科研与实践创新计划项目(KYCX20_0542)。

摘　　要：基于等应变假设,采用非线性渗透及压缩模型,考虑真空度沿深度线性衰减以及随指数时间增加、附加应力随深度线性减小、有效电压随时间指数衰减特征,推导瞬时加载、单级加载和多级加载方式下的真空堆载预压联合电渗竖向排水地基非线性固结解析解。通过与现有文献中的试验和数值结果对比,验证推导的解析理论的正确性。在此基础上,利用该解对真空度、附加应力及有效电压的变化开展参数分析。结果表明:真空度沿深度衰减将减小最大负孔压及沉降,但对固结速率影响较小;初期固结速率随着真空度增长速率的加快呈非线性增长;多级加载可有效减小堆载引起的超静孔压,确保地基稳定;考虑附加应力沿深度减小,计算得到的超静孔压及最终沉降将显著减小;有效电压残余值越大、衰减速率越慢,对应的最大平均负孔压和沉降越大;固结速率随着有效电压衰减速率加快呈非线性减小趋势。Based on the equal strain assumption and nonlinear permeation and compression models,analytical solutions for instantaneously loading,single stage loading and multi-stage loading under combined electroosmosisvacuum-surcharge preloading,considering the variations of vacuum degree with depth and time,the decrease of additional stress with depth,and the decrease of effective voltage with time,were proposed. The proposed analytical solution was validated by comparing with the experimental and numerical results in the literature,and a parametric study was conducted to investigate the variations of the vacuum degree,the additional stress and the effective voltage with depth and time. The results show that the reduction of the vacuum degree with depth will induce the decrease of the maximum negative pore water pressure and the settlement but has little influence on the consolidation rate. The initial consolidation rate increases nonlinearly with the increase rate of the vacuum degree. The multi-stage loading will effectively decrease the excess pore water pressure induced by loading,which ensures the stability of the soft foundation after loading. The excess pore water pressure and the final settlement will decrease obviously due to the reduction of the additional stress along depth. The larger the residual value of the effective voltage or the smaller the decrease rate of the effective voltage,the larger the maximum average negative pore water pressure and the settlement. Moreover,the consolidation rate decreases nonlinearly with the decrease rate of the effective voltage.

关 键 词：土力学 真空–堆载预压 电渗 竖向排水 固结 解析解 

分 类 号：TU43[建筑科学—岩土工程]