Experimental Study on Secondary Consolidation Coefficient of Clayey Soil in Cangzhou Land Subsidence Zone
The consolidation deformation of clayey soil layer is an important cause of ground settlement,and secondary consolidation coefficient is an important parameter of secondary consolidation deformation.Secondary consolidation tests were carried out by obtaining undisturbed clay samples of different depths and prepared remodeled soil samples,and the effects of e-lg(t)curve,load and time on secondary consolidation coefficients were analyzed,and then the relationship formula reflecting the time effect of secondary consolidation coefficients was established.The results show that:the curve of pore ratio during the secondary consolidation stage shows a non-linear variation with time.When the consolidation pressure is greater than and less than the initial consolidation pressure,the curve shows an upward convex and upward concave shape,respectively.The coefficient of secondary consolidation is influenced by consolidation pressure and time.It is found that when the over consolidation ratio is greater than 1 and the over consolidation ratio is less than or equal to 1,the coefficient of secondary consolidation gradually decreases and increases with time,respectively.We have established an empirical formula for the coefficient of secondary consolidation when the over consolidation ratio is greater than 1,and verified it using experimental data.The research results can provide a basis for the calculation of secondary consolidation deformation in the Cangzhou area.
land subsidence areaclayey soilsecondary consolidation coefficientconsolidationtime effect