摘要
对用不同制样方法得到的饱和膨润土及其与砂混合物进行了压缩试验。试验结果表明,饱和膨润土的压缩曲线呈双线性,不同于普通黏土的压缩曲线。压缩试验中量测了侧向应力,由此得到的饱和膨润土的静止侧向压力系数值较一般黏土的数值要大。对膨润土与砂混合物的击实样进行了由非饱和到饱和状态的浸水试验,并得出试验过程中侧向应力的变化规律。由于浸水饱和的试样和抽真空饱和的试样在较高压力时压缩曲线趋于一致,可采用快速抽真空饱和的方法进行试验研究,以缩短非饱和混合物击实样浸水饱和所需时间。引入骨架孔隙比的概念,用来判断膨润土与砂混合物中砂骨架是否形成,得出影响混合物压缩特性的决定因素。
The compression tests are completed on saturated bentonite and sand-bentonite mixtures with different preparations. The test results show that the compression curves present a bilinear shape, which is different from that of ordinary normal consolidated clays. The coefficient of lateral earth pressure of saturated bentonite at-rest is obtained by Ko-oedometer; and the K0 value is greater than that of ordinary clays. The change in the lateral stress is obtained during the water uptake test on compacted sand-bentonite mixtures which is transited from unsaturated to saturated states. The compression curves of compacted specimens saturated by the water uptake test and the vacuumized methods tend to be consistent in the relatively high stress range. Thus the vacuumized method for saturating the specimens can be adopted to save time for performing the water uptake test. The concept of skeleton void ratio is used to judge if the sand skeleton is formed in sand-bentonite mixtures, and to obtain main factors affecting the compression behaviour of the mixtures.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2009年第11期3249-3255,共7页
Rock and Soil Mechanics
基金
国家自然科学基金(No.10572081)
上海大学研究生创新基金(No.shucx080168)
作者简介
孙文静，女，1981年生，博士研究生，主要从事非饱和土力学的研究。E-mail：wjsun@shu．edu．cn
