摘要
基于非牛顿指数描述的非达西渗流定律,同时考虑地基内部竖向附加应力随深度线性变化以及变荷载的影响,建立了一维固结控制方程并应用有限差分法进行数值求解,同时对不同参数单级加荷下的固结性状进行分析。结果表明:基于非达西渗流比达西渗流下固结速率要慢,且渗流模型中非牛顿指数越大,土层的固结速率越慢;土层厚度越厚,固结速率越慢,因此,传统固结理论中室内土样与地基土层之间的相似关系不再成立;作用于土层的平均附加应力越大,土层的固结速率越快;在单面排水情况下,附加应力分布对土层固结速率有较大影响;相反,双面排水条件下土层固结速率与附加应力的分布是无关的;荷载的加荷速率越快,则土层的固结速率越快。最后,讨论了达西渗流计算固结变形的适用范围。
Based on the non-Darcy flow described by non-Newtonian index, the theory of one-dimensional consolidation is modified to consider a linear variation in the additional stress with depth and the effect of time-dependent loading. The numerical solutions are derived in detail by FDM for pore water pressure and the average degree of consolidation. The influence of various parameters on consolidation behavior is investigated. The results show that the rate of consolidation is reduced when non-Darcy flow is considered; furthermore, the greater the non-Newtonian index, the slower the rate of consolidation. The greater the thickness of a soil layer, the slower the rate of consolidation. Thus, the classical similitude with non-Darcy flow between laboratory samples and field layers is no longer satisfied. The greater the value of the additional stress in a foundation, the faster the rate of consolidation. The distribution of additional stress has a great influence on the rate of consolidation for the case of single drainage condition; on the contrary, the rate of consolidation is independent of the distribution of additional stress for the case of double drainage condition. The faster the loading rate, the faster the consolidation rate. Finally, applicability of Darcy＇s flow to consolidation deformation is discussed.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2011年第1期281-287,共7页
Rock and Soil Mechanics
基金
国家自然科学基金资助(No.50878191)
关键词
非达西渗流
非牛顿指数
一维固结
变荷载
non-Darcy flow
non-Newtonian index
one-dimensional consolidation
time-dependent load
