北京平原区软弱黏性土次固结系数的试验研究

EXPERIMENTAL INVESTIGATION ABOUT SOFT COHESIVE SOIL COEFFICIENT OF SECONDARY CONSOLIDATION IN BEIJING PLAIN

次固结系数通常被认为是一个常数,然而,大量的实验数据表明,随着时间的改变次固结系数也发生着变化。同样,大量的试验表明次固结系数与固结压力、压缩指数、含水率以及塑性指数有着一定的相关性。本文在着重研究北京平原区软弱黏性土次固结特性的基础上,对其规律进行了总结和分析。结果表明:对超固结土,次固结系数随荷载的增大而增大;对正常固结土,次固结系数随荷载增大而减小。次固结系数亦随着土样含水率和塑性指数的增长呈线性增长趋势,且Cα/Cc比值为常数。

The secondary consolidation coefficient has been considered constant in engineering. However, there are many research findings that the secondary consolidation coefficient is not a constant by means of laboratory test. The coefficient can change with the time. The secondary consolidation coefficient has nothing to do with the consoli- dation pressure. But many tests also show that the secondary consolidation coefficient has some correlations with the consolidation pressure, compression index, moisture content and plasticity index. This paper studies the secondary consolidation properties of soft cohesive soil in Beijing plain. It finds and analyses these relations. The results show that for the over-consolidated soil, the coefficient of secondary consolidation increases as the load increases. For the normal-consolidated soil, it decreases as the load increases. It also keeps a linear increase with moisture content and plasticity index. The ratio of CoJCc is a constant.