湖相软粘土力学特性的试验研究  

An experimental study of the mechanical behavior of lacustrine soft clay

作　　者：陈波[1] 胡云世[1] 张效忠[1] 

机构地区：[1]衢州学院建筑工程学院,浙江衢州324000

出　　处：《水文地质工程地质》2014年第3期76-81,共6页Hydrogeology & Engineering Geology

摘　　要：为研究结构性对软粘土力学特性的影响,对江苏宝应湖相沉积软粘土原状样与不同重塑样进行一系列的压缩、剪切试验研究。根据单向压缩试验得到的压缩曲线,得到不同土体的压缩指数Cc、回弹指数Cs,并确认了结构性对土体变形特性的影响。根据三轴剪切试验结果,比较原状样和不同重塑样的应力-应变-孔压曲线,确认了结构性和孔隙比对土体的强度特性具体有重要影响,并从孔隙比角度合理的解释了为什么高围压下原状样强度反而小于重塑样的强度。最后,提出简单量化土体组构的参数参考孔隙比e*10,将试验结果用参考孔隙比e*10归一化整理后,发现原状样和不同重塑样的Cc-e*10、ef/e*10-log pf,ef/e*10-log qf曲线基本一致。据推断出原状样在结构屈服应力后,结构中的胶结已基本破坏,原状样和重塑样的变形、强度差异主要是由于组构的差异引起的,且土的组构参数可用参考孔隙比e*10表示。A series of triaxial tests have been carried out on the undisturbed,remolded and reconstituted samples obtained from Baoyao,Jiangsu. They are employed to study the effect of soil structure on the mechanical behavior of clay. Comparison of compression curves obtained from the test confirms that the soil structure has great effect on the deformation characteristic of clay. By comparing the stress-strain-pore pressure curves obtained from triaxial tests,it is found that the strength of clay are affected by soil structure and void ratio,and the strength of undisturbed samples is lower than that of the remolded or reconstituted samples at high confining pressures caused by larger void ratio. Finally,the reference void ratio e＊ 10is simply introduced to quantify the soil fabric in this paper. The compression and shear test results dealing with the reference void ratio e＊ 10shows that the Cc-e＊ 10、ef/ e＊ 10-log pf,ef/ e＊ 10-log qfare almost the same for the three different samples. Based on the above normalized results,it can be deduced that if the stress is larger than the structure yield stress,most of bonding is destructured and the difference betweer deformation and strength among the undisturbed,remolded and reconstituted samples are caused by the soil fabric,which can be expressed by the reference void ratio e＊ 10.

关 键 词：软粘土 结构性 孔隙比 组构 参考孔隙比 

分 类 号：TU411.3[建筑科学—岩土工程]