密度对砂土应力应变强度特性影响试验研究  

Experimental study on stress-strain-strength behavior of sand with different densities

作　　者：朱俊高[1] 史江伟[1] 罗学浩 徐佳成[3] 

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]智性科技南通有限公司,江苏南通226010 [3]中国国际工程咨询公司,北京100048

出　　处：《岩土工程学报》2016年第2期336-341,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家重点基础研究发展计划("973"计划)项目(2013CB036404);高等院校博士学科点专项科研基金项目(20110094110002);江苏省"六大人才高峰"项目(JZ-011)

摘　　要：针对某级配砂土,对不同密度试样进行常规三轴固结排水剪切试验,探讨了密度对砂土应力应变特性、强度特性的影响。试验结果表明:密度对砂土应力应变的形态影响不大,对试样破坏时的轴向应变有显著影响;砂土试样发生相变时的体积应变受密度影响显著。通过研究密度和围压对变形的影响,定量分析了相变体积应变随相对密实度和围压的变化关系,同时,发现砂土密度对其变形模量影响较大;密度对试样破坏偏应力比影响较大。试样砂土的强度指标总体上随相对密实度增大而增大,但在试验范围内影响有限。对非线性指标φ_0,Δφ,随试样相对密实度变化均可近似用直线表示;D_r每增大0.1,内摩擦角φ增大0.66°。The influences of density on the stress-strain properties and strength of sand with the same gradation are investigated by using the triaxial consolidation drained shear tests on the samples with different densities. The experimental results show that the density has little impact on the shape of stress-strain curve. The axial strain at failure as well as the axial and volumetric strains for deformation is significantly affected by the density. Through analyzing the influences of density and confining pressure on the axial and volumetric strains for deformation, the relationships among strains, densities and confining pressures are established. The density has great influences on the deviator stress ratio at failure, while the influences on the residual deviator stress can be ignored. The strength index increases with the increase of the relative density generally. In terms of the nonlinear indexes such as φ_0 and Δφ, its relationship with change of the relative density is approximately linear, and the internal friction angle increases by 0.66 degrees with the increment of D_r of 0.1.

关 键 词：砂土 三轴试验 密度 围压 应力应变 强度 

分 类 号：TU411[建筑科学—岩土工程]