为研究变荷载作用下软土的一维非线性固结特性,通过引入新的一维非线性压缩模型,推导出变荷载作用下考虑非达西渗流的饱和软土地基一维非线性固结方程。基于有限差分法求解,并通过与半解析解结果对比分析,验证了其合理性与可靠性。根据该固结方程的解答,详细讨论了非达西渗流参数(m和i1)、土体初始压缩系数、压缩指数与渗透指数的比值以及加载速率与加载形式对土体固结的影响。结果表明:随着非达西参数(m和i1)及压缩指数与渗透指数的比值的增大,土体的固结速率减慢;土体初始压缩系数越大,土体的固结速率越快;荷载的加载速率越快,土体的固结速率就越快;与已有模型相比,引入的新模型无需测量土体的初始有效应力,可更加方便地应用于工程中。
Abstract
To investigate the nonlinear consolidation behavior of soft soil under varying loads in one dimension, we introduce a novel one-dimensional nonlinear compression model to establish the one-dimensional nonlinear consolidation equation in consideration of non-Darcy flow for saturated soft soil subjected to variable loads. The equation is solved using the finite difference method. The excellent agreement between the obtained results and the analytical solution confirms the validity and reliability of the equation. Based on the solution of the consolidation equation, we thoroughly examine the effects of non-Darcy seepage parameters (represented by m and i1), the initial compressibility coefficient of the soil, the ratio of compression index to permeability index, as well as the rate and form of external load, on soil consolidation. The results demonstrate that an increase in the non-Darcy parameters (m and i1) and the ratio of compression index to permeability index leads to a decrease in the consolidation rate of the soil. Moreover, a higher initial compression coefficient or larger loading rate results in a faster consolidation rate. In comparison with existing models, the established model in this study eliminates the need for measuring the initial effective stress of the soil. Consequently, it can be more easily applied to engineering.
关键词
软土 /
非达西渗流 /
一维非线性固结 /
变荷载作用
Key words
soft soil /
non-Darcy flow /
one-dimensional nonlinear consolidation /
variable load action
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基金
国家自然科学基金项目(51879104);高等学校博士学科点专项科研基金项目(20130161110017)
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