深厚表土底部含水层疏水沉降试验及数值模拟研究

Experiment of dewater settlement of bottom aquifer in overburden and its numerical simulation study

通过对19个砂土试样实施的疏排水渗透和沉降均匀设计试验,得出:渗透系数与有效应力之间呈现指数型的衰减变化规律;侧限条件下的压缩模量与水压降呈正相关关系,有效应力越大,压缩模量越大.用大分层和小分层相结合的方法来处理疏排水沉降的差分格式所编写的程序计算表明:数值模拟结果与试验结果有很高的拟合程度,该方法用于疏排水沉降量的计算是可靠的;理论公式应用于疏排水沉降量的计算将导致疏排水初期计算结果偏小,疏排水后期计算结果偏大.

According to the results of the uniform experiment design of dewater permeability and settlement implemented on 19 sand samples, such conclusions could be reached as following: A law of delaying exponential is presented between the permeability coefficient and the effective stress; under constrained conditions the compressibility modulus varies positively with the diminution of hydraulic pressure, namely, the larger the effective pressure is, the bigger the compressibility modulus is.The program dealing with dewater settlement written by the author in a format of difference combining large and small layers indicates that the results of numerical simulation matches perfectly with that of experiment design, so it is reliable to get the quantity of dewater settlement with such method.Meanwhile, if the theoretical formular is applied to the calculation of dewater settlement, the results will be lower in initial stages than actual while be higher in later stages.