摘要
非饱和残积土是厦门地区诸多填方工程的工程用土,而岩土工程的强度与稳定性问题都涉及到非饱和土的抗剪强度及其指标.采用滤纸法测定非饱和残积土的基质吸力,通过一系列的直接剪切试验,测定不同初始含水量状态下土的抗剪强度及其强度指标.试验结果表明:基质吸力随着含水量、体积含水量或饱和度的增加而减小.当含水量小于16%,体积含水量大于35%或者饱和度大于70%时,基质吸力对含水量的变化非常敏感.在低基质吸力区,抗剪强度随着基质吸力的增加显著增加,表观粘聚力随基质吸力的增大而线性增加;在高基质吸力区,强度随基质吸力的增加变化不大,表观粘聚力的增长速率减小.表观内摩擦角仅在基质吸力较小时增加而后可近似为某一定值.
Unsaturated residual soils are often used as backfills of engineering structures in Xiamen. The strength and stability of many geotechnical structures are related with the shear strength of unsaturated soils. A series of direct shear tests were carried out on unsaturated residual soils with different initial moisture contents and matric suction was conducted by filter paper method. Results of tests show that matric suction decreases greatly with increasing of gravimetric moisture content, volumetric moisture content and degree of saturation when gravimet- ric moisture content is less than 16%, volumetric moisture content is less than 35% or degree of saturation is less than 70%. The shear strength and apparent cohesion increase greatly with increasing of matric suction in lower matric suction range and then the increasing rates of them decrease in higher matric suction range. Apparent internal friction angle increases at first with the increasing matric suction and then be approximated to a certain value.
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
2012年第5期877-881,共5页
Journal of Xiamen University：Natural Science
基金
厦门大学2011年度大学生创新性实验计划项目
关键词
基质吸力
滤纸法
残积土
初始含水量
抗剪强度
matric suction
filter paper method
residual soil
initial moisture content
shear strength
