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砂泥岩混合料是砂岩颗粒和泥岩颗粒按一定比例混合的一种常见的填筑土体,因其取材方便而经常被用于水库、路堤、基坑开挖、渠道等实际工程中。本文通过GDS三轴试验系统,对砂泥岩混合土体在不同的砂泥岩颗粒比例、干密度和含水率情况下的强度和变形特性进行了分析。结果表明:低围压时,砂泥岩混合料应力-应变关系曲线表现为应变软化型,随着围压的增加曲线表现为应变硬化型;含水率对砂泥岩混合料应力-应变关系曲线的形态影响不大,偏应力峰值强度随着含水率的增大先增加后减小;干密度较小时,砂泥岩混合料应力-应变曲线表现为应变硬化型,随着干密度的增加,应力-应变曲线形态向应变软化型转变;砂泥岩混合料抗剪强度参数均随干密度的增加而增大;土体抗剪强度参数随砂岩颗粒含量的增加而增加。
Sand-mudstone mixture is a kind of common soil which sandstone particles and mudstone particles are mixed according to a certain proportion. Because of its convenient materials, it is often used in practical projects such as reservoirs, embankments, excavation of foundation pit and channels. In this paper, the GDS triaxial test system was used to analyze the strength and deformation characteristics of sand-shale mixed soil with different proportion of sand-shale particles, dry density and moisture content. The results show that the stress-strain curve of sand-shale mixture shows strain-softening type under low confining pressure, and the curve shows strain hardening type with the increase of confining pressure. The shape of the stress-strain curve And the peak stress of deviatoric stress firstly increases and then decreases with the increase of water content. When the dry density is small, the stress-strain curve of sand-shale mixture shows strain hardening. With the increase of dry density, the stress-strain The curve shape changes towards strain softening; the shear strength parameters of sand-shale mixture increase with the increase of dry density; the shear strength of soil increases with the increase of sandstone content.