基于Forchheimer渗流的土石混合体单向固结模型研究

Research on One-dimensional Consolidation Model of Soil-rock Mixtures Backfill under Forchheimer Seepage Model

土石混合体回填土的渗流属于非达西渗流,不符合Terzaghi固结理论的前提。因此,土石混合体回填土的固结沉降问题难以依靠Terzaghi固结理论解决。经验证Forchheimer渗流模型符合土石混合体的渗流特性,基于Forchheimer渗流模型并加以理论推导,建立了欠固结饱和土石混合体回填土线性单向固结模型。利用MATLAB软件编制有限差分计算程序,将有限差分解与达西解析解以及固结压缩试验结果进行对比,验证有限差分解的有效性。结果表明:基于Forchheimer渗流模型推导得到的线性单向固结模型能够较好地预测分析土石混合体的固结沉降,对西南地区欠固结土石混合体回填土固结沉降问题具有理论指导意义。

The seepage in the soil-rock mixture belongs to non-Darcy flow and it does not conform to the premise of Terzaghi’s consolidation theory.Therefore,the consolidation settlement of soil-rock mixture backfill can hardly be solved by Terzaghi’s consolidation theory.Based on Forchheimer seepage model which was confirmed to accord with the seepage characteristics in soil-rock mixture,the linear one-dimensional consolidation model of the under consolidated saturated soil-rock mixture is established by theoretical derivation,with its finite difference solution calculated.The program of finite difference calculation is compiled by MATLAB software to verify the effectiveness of finite difference solution,and the finite difference solution is compared with Darcy’s analytical solution and the results of consolidation compression test.The results show that the linear one-dimensional consolidation model derived from the Forchheimer seepage model can predict and analyze the consolidation settlement of the soil-rock mixture well,and is of theoretical significance to the consolidation settlement of the under consolidated soil-rock mixture backfill in the southwest region.