连续排水边界条件下考虑自重的地基一维固结分析

STUDY ON ONE-DIMENSIONAL CONSOLIDATION CONSIDERING SELF-WEIGHT UNDER CONTINUOUS DRAINAGE BOUNDARY CONDITIONS

基于连续排水边界条件,建立考虑自重的地基一维固结方程,利用有限正弦Fourier变换方法,给出了解析解,然后通过数值方法获得不排水对称面,分析了界面参数和自重系数对不排水对称面的影响。针对实际工程中水平排水砂垫层铺设位置的优化问题,通过建立考虑土体自重下的固结数学模型,运用半数值半解析方法获得了土体在不同时间因数下设置排水砂垫层的最优位置。分析了水平排水砂垫层设置位置对地基固结度的影响,并进一步给出不同土体界面参数下砂垫层最优铺设位置与时间的关系图。结果表明:考虑土体自重的不排水对称面随时间变化,自重系数越大,不排水对称面越靠近土体底部;最优砂垫层铺设位置是随时间不断变化的。最后,通过一个算例表明考虑优化砂垫层对于固结时间效率的提高具有明显效果。

Based on continuous drainage boundary conditions, the one-dimensional consolidation equation considering self-weight is established. Using the Finite Sine Fourier transform method, the analytical solution is proposed, and the undrained symmetric plane is presented by the numerical method. The influence of the interface parameter and gravity coefficient on the undrained symmetric plane is discussed. Aiming at the optimization problem of horizontal drain in engineering practice, the consolidation equation considering self-weight is established, and the optimal position of the sand blanket under different time factors is proposed by the semi-analytic method. The influence of the sand blanket position on the consolidation degree is investigated, and the relationship chart of the position and time of the optimum sand blanket under different soil interface parameters is further given. The results show that the undrained plane considering self-weight varies with time. The larger the weight coefficient is, the closer to the bottom soil is the undrained plane of symmetry. The optimal placement of sand blanket also varies with time. An engineering example is provided to show that the optimization of drainage sand blanket has obvious effect on the improvement of consolidation time efficiency.