花岗岩残积土抗剪强度的尺寸效应研究  

Size Effect on the Shear Strength of Granitic Residual Soils

作　　者：林孔斌 柯国贵 

机构地区：[1]福州大学环境与资源学院资源与城乡建设系,福州350116 [2]福建省交通规划设计院,福州350004 [3]地质工程福建省高校工程研究中心,福州350116 [4]福建省林业勘察设计院,福州350001

出　　处：《土工基础》2017年第4期521-525,共5页Soil Engineering and Foundation

基　　金：国家自然科学基金(41102167);福州大学科技发展基金(2011-XQ-12)

摘　　要：针对花岗岩残积土原状样、重塑样和剔除粒径大于5mm颗粒的重塑样,分别进行小型、中型和大型3种不同直径试样的三轴固结不排水剪切试验,研究了不同试样尺寸下花岗岩残积土的应力-应变特性,探讨了颗粒大小和试样尺寸对花岗岩残积土应力-应变特性及抗剪强度的影响。研究表明:不同尺寸大小的试样所测定的应力-应变关系相似,但量值大小有差异;存在超粒径颗粒会造成土样的有效粘聚力偏高,有效内摩擦角偏低;当不存在超粒径颗粒时,随着试样尺寸的增加,土样的有效粘聚力增大、有效内摩擦角减小,且其变化趋势具有线性规律,总粘聚力减小、总内摩擦角增大;总体来说,粘聚力变化较大,内摩擦角变化较小。To investigate the soil grain size as well as the sample size effect on the stress-strain characteristics of the granitic residual soils,consolidated undrained triaxial shear tests were performed on remolded granitic residual soils with grain sized greater than 5mm removed under three different sample diameters for the triaxial shear tests.The results indicate that the stressstrain curves from samples tested under different diameters are similar with different stress magnitudes;the presence of the large grain size in the sample will increase the tested effective cohesion and reduce the internal friction angle.When the large grain soils are removed from the samples,with the increase of the sample diameters,the tested effective cohesion increases and the effective internal friction angle reduces.However,the total cohesion reduces and total internal friction angle increases with the sample diameters.In general,the sample size has a larger impact on the effective cohesion and less impact on the effective internal friction angle.

关 键 词：花岗岩残积土 尺寸效应 三轴试验 抗剪强度 应力变形特性 

分 类 号：TU458[建筑科学—岩土工程]