论文部分内容阅读
对黏粒含量为34%的粉土泥浆样进行无宏观裂缝出现的慢速干化试验,对干化至不同目标含水率的试样进行压汞试验,获得孔隙分布曲线,系统地研究干化过程中粉土微观结构的演变规律,分析微观裂隙的形成及发展机制。研究结果表明:随着干化的发展,最大进汞量逐渐减小,当含水率达到缩限后,最大进汞量保持不变;不可侵入孔随干化逐渐增多,当含水率小于缩限后,不可侵入孔增大的趋势减缓;当含水率大于缩限前,孔径分布(PSD)曲线峰值对应孔径随干化呈单调递减的关系,含水率继续减小至缩限以下时,峰值对应孔径逐渐增大至固定值;由饱和到非饱和过渡时,PSD曲线在0.1~1?m范围有隆起并达到最大,随着干化的深入,隆起减小直至消失。PSD曲线峰值孔径随干化先减小后增大的趋势以及隆起随干化的变化规律,均证明干化过程中有可能产生微观裂隙,并反映了微观裂隙的演变过程。粉土泥浆样干化过程中,当由饱和过渡到非饱和状态时,黏土会像“外套”一样裹在粉土颗粒周围,微观裂隙在黏土颗粒间及黏土颗粒与粉土颗粒间的交界面上开始出现,该微观裂隙和宏观干燥裂缝在本质上是不同的,是对土体龟裂研究机制的补充。
The silty mortar samples with clay content of 34% were subjected to a slow drying test without macroscopic cracks, and the mercury penetration test was carried out on the samples dried to different target moisture contents to obtain pore distribution curves. The effects of drying The process of silt microstructure evolution of the law to analyze the formation of micro-cracks and development mechanism. The results show that with the development of drying, the maximum mercury intrusion gradually decreases. When the moisture content reaches the limit, the maximum mercury intrusion remains unchanged. The invading pores gradually increase with the drying. When the moisture content is less than the limit When the moisture content is larger than the limit, the peak corresponding to the pore size distribution curve (PSD) shows a monotone decreasing relationship with the dry pore size. When the moisture content continues to decrease below the limit, the peak corresponds to The pore size gradually increases to a fixed value. When the transition from saturation to non-saturation occurs, the PSD curve reaches a maximum in the range of 0.1 ~ 1 μm and reaches the maximum with the deepening of drying. The peak pore size of PSD curve decreases firstly and then increases with the increase of dryness, and the regularity of the variation of updip dry-dry shows that microcracks may be generated during the drying process and reflect the evolution of microscopic fractures. In the process of silt mud-like drying, the clay will be wrapped around the silt particles like “jacket” when the transition from saturated to unsaturated state occurs. The micro-cracks are between clay particles and between clay particles and silt particles The interfaces begin to appear. The microscopic fractures and the macroscopic dry fractures are different in nature and complement the research mechanism of soil cracking.