卸荷作用下饱和软黏土次固结变形研究

Study on Secondary Deformation of Saturation Soft Clay from Unloading Tests

通过室内土工试验研究了饱和软黏土在卸荷条件下的次固结变形规律。结果表明:软黏土试样的次固结系数与固结压力无关;超载预压对软黏土的次固结变形有显著影响,其预压卸荷后的次固结系数减小。讨论了计算软黏土次固结变形时各参数的取值,并根据现场实测资料,分析了软土层卸荷后的变形特点,应用次固结变形计算公式对地基沉降进行了预测,结果表明:实测最大沉降量与预测值变化趋势相似,利用计算附加次固结变形的公式可以预测软土地基的长期沉降变形。

The secondary consolidation deformation of saturation soft clay in the total deformation takes up a large proportion.A large number of indoor tests studied the secondary consolidation deformation characteristics of saturated soft clay from unloading conditions.Research shows that the consolidation coefficient has nothing to do with the consolidation pressure of soft clay.The ratio of the consolidation coefficient to compression index is a constant;surcharge preloading has a significant influence on secondary deformation of soft clay;the secondary consolidation coefficient decreases after unloading.The paper discussed the each parameter selection about calculation secondary consolidation deformation of soft clay times,and analysis the deformation characteristics of clay from unloading based on the in-situ measured data.Finally the paper gives prediction on secondary consolidation settlement of the foundation using calculation formulae.