基于Gibson大变形固结方程的软基沉降预测方法

Settlement prediction of soft clay foundation based on Gibson large-strain consolidation equation

基于Gibson大变形固结方程,结合吹填淤泥高压固结试验成果,对简化该方程的3个假定条件进行了验证,在此基础上提出了分级荷载下双层软基沉降预测的大变形固结简化方法,将其应用于围海造陆工程吹填淤泥与原状淤泥双层软基沉降过程预测,结果表明:1)常规预压荷载(≤200 kPa)下,固结压力0～25 kPa与25～200 kPa范围内,吹填淤泥的孔隙比e与有效应力及渗透系数与(1+e)分别满足线性关系,大变形固结系数近似为常数;2)大变形固结简化方法预测的双层软基沉降曲线相比于经典固结理论,更接近于实测曲线,为软基沉降预测提供了一种简易实用的方法。

Based on the Gibson large-strain consolidation equation,three assumption conditions of simplified equation are verified by the analysis of high pressure consolidation tests of dredged fill.Large-strain consolidation simplied settlement prediction method of double-layered soft clay foundation is proposed under step load,which be applied to the settlement process prediction of double-layered soft clay foundation of dredged fill and marine deposit silt in land reclamation projects.The obtained results verified that： 1）The relationship of void ratio e-effective stress and coefficient of permeability k-（1＋e） of dredged fill is linear,and large-strain coefficient of consolidation of dredged fill is approximately constant under different consolidation pressure of 0～25 kPa and 25～200 kPa.2）Compared with the classical consolidation theory,the consolidation settlement process of double-layered soft clay foundation obtained by the large-strain consolidation simplified method is more reasonable,which provides a facility and practical settlement prediction method for soft clay foundation.