南京河西地区软土次固结特性试验探究

Experimental study on secondary consolidation characteristics of soft soil in Hexi region of Nanjing

河西地区广泛分布着淤泥质粉质黏土,这种含水量高、流变性强的土样承载力较差,用作建筑地基时会影响建筑物的安全,因为主固结完成后往往伴随着次固结变形,研究这一现象对建筑物工后沉降有重大意义。文章取用该地区的原状、重塑土样进行室内一维次固结试验,主要分析次固结的过程,以及次固结系数与压力、塑性指数的关系等,进一步探究主、次固结阶段的划分。试验结果表明,该地区的软黏土的蠕变变形会经历初始、稳定、加速蠕变3个阶段,且与重塑土样相比,原状土样有更高的次固结系数。

In lhe Hexi region, silty clay is widely distributed. The soil with high water content and strong rheological properties is poor, and it can affect the safety of buildings when used as a foundation. Because the main consolidation is often accompanied by the seeondary eonsolidation deformation, the study of this phenomenon on the post-construction settlement of the building is of great significance. This paper is to take the original state of the region, reshaped soil samples for indoor one-dimensional consolidation test, mainly to analyze the proeess of sub-consolidation, as well as the secondary consolidation coefficient and pressure, plasticity index, and further explore the main, secondary eonsolidation stage of the division. The results show that the creep deformation of the soft clay in this area will be affected by three stages： initial, stable and accelerated creep. Compared with the remolded soil samples, the subsurfac soil samples have higher seeondary consolidation eoeffieient.