非饱和网纹红土比例加载特性研究  

Research on behavior of unsaturated reticulate red clay under proportional loading

作　　者：徐有娜 李建中[2] XU Youna;LI Jianzhong(China Institute of Geotechnical Investigation and Surveying Ltd.,Beijing 100007,China;School of Geosciences and Info-physics,Central South University,Changsha Hunan 410083,China)

机构地区：[1]建设综合勘察研究设计院有限公司,北京100007 [2]中南大学地球科学与信息物理学院,湖南长沙410083

出　　处：《钻探工程》2021年第2期117-124,共8页Drilling Engineering

基　　金：国家自然科学基金资助项目“非饱和网纹红土的蠕变与加载速率效应研究”(编号:41572269)。

摘　　要：通过利用应力控制式全自动GDS静三轴仪对含水率相同、干密度相同的重塑网纹红土进行不同基质吸力条件下的恒应力比的三轴固结排水试验,研究了非饱和网纹红土比例加载特性。研究结果表明:(1)在不同恒应力比的分级加载条件下,非饱和网纹红土的基质吸力平衡过程中,反压排水量有一个明显的转折点,此转折点可作为判断基质吸力是否到达平衡的标志;(2)通过对比不同基质吸力下的轴向应变和时间的关系曲线发现,基质吸力的增加引起轴向应变增加;(3)在偏应力保持不变的条件下,基质吸力的增加没有引起轴向应变的显著增加;(4)不同基质吸力条件下的偏应力和净平均应力之间呈直线关系,其斜率近似为恒应力比;(5)提出了一种可以预测非饱和网纹红土比例加载条件下的径向应变的方法。With the stress⁃controlled automatic GDS static triaxial gauge,the behavior of unsaturated reticulated red clay under proportional loading was studied through triaxial consolidation and drainage test at constant stress ratio for the remolded reticulate red clay with the same moisture content and dry density at different matric suctions.The experimental results show that:(1)The back pressure displacement of unsaturated reticulate red clay has an obvious turning point in the process of matric suction equilibrium at different constant stress ratios,which can be used as a marker to judge whether matric suction reaches equilibrium or not;(2)By comparing the relation curves of axial strain and time at different matric suctions,it was found that the increase of stromal suction caused the increase of axial strain;(3)Under the condition that the deviator stress remains unchanged,the increase of matric suction does not cause a significant increase of axial strain;(4)There is a linear relationship between the deviator stress and the net mean stress at different matric suctions,and its slope is approximate to the constant stress ratio;(5)A method is proposed to predict the radial strain of unsaturated reticulate red clay under proportional loading.

关 键 词：非饱和土 网纹红土 恒应力比 应变 加载特性 

分 类 号：P642.1[天文地球—工程地质学] TU43[天文地球—地质矿产勘探]