昆明盆地泥炭质土动力学参数统计研究

泥炭质土在昆明盆地分布广泛,由于其工程性质差,因此其土动力学性质受到许多学者的重视。首先收集近年来昆明盆地内埋深为0~100 m的62个取样点,128组泥炭质土样的动三轴实验数据进行统计分析,得到了泥炭质土的不同剪应变下的动剪切模量比和阻尼比的统计值;然后讨论土动力学参数随埋深的变化特征,并与《工程场地地震安全性工作规范》给出的黏土值、粉质黏土值、淤泥质黏土值进行了对比;最后在昆明盆地内挑选了2个典型钻孔模型,分别输入统计值、实测值、规范黏土值、粉质黏土值、淤泥质黏土值,进行一维土层反应分析计算。结果表明:规范给出的黏土值、粉质黏土值、淤泥质黏土值与泥炭质土实测值得到的结果差异较大,泥炭质土统计值与实测值得到的结果差异较小。当现场工作取样困难,得不到可供试验的原状样时,可考虑选择使用本文的泥炭质土统计值。

Statistical Analysis on Dynamic Parameters of Peaty Soil in the Kunming Basin

Peat soil are widely distributed in the Kunming Basin,but its engineering properties are poor,and its dynamic properties are valued by many scholars. In this paper,the dynamic parameters of peat soil in the Kunming basin are collected,and statistical analysis is made to obtain the statistical values of shear modulus ratio G/Gmax and damping ratio λ of peat soils. We selected two typical borehole models in the Kunming basin,entered the statistical values or measured values,and used the one-dimensional soil response analysis to calculate. The results of the statistical values calculated were not different from the results of the measured values calculated. If it is difficult to get the original sample that can be tested,one can consider using the statistical values of this paper.