主应力轴旋转下中主应力系数对重塑盐渍土变形特性的研究  

Study on the effect of the intermediate principalstress coefficient on the deformation characteristics of remoldedsaline soil under the rotation of principal stress axis

作　　者：鲁生斌 马艳霞[1] Lu Shenbin;Ma Yanxia(School of Civil Engineering,Qinghai University,Xining 810016,China)

机构地区：[1]青海大学土木工程学院,西宁810016

出　　处：《青海交通科技》2023年第2期101-106,共6页Qinghai Transportation Science and Technology

基　　金：青海省科技厅应用基础研究项目(2018—ZJ—749)。

摘　　要：为研究三维复杂应力状态下重塑盐渍土变形和强度的影响,采用空心圆柱扭剪仪对重塑盐渍土开展定向剪切和主应力轴往复旋转后定向剪切两种应力路径下的研究,分析八面体剪应力—剪应变的发展以及各应变分量和强度的变化规律。研究结果表明:不同中主应力系数下,经历主应力轴往复旋转后剪切时试样破坏需要的剪应力比定向剪切需要的剪应力小,定向剪切时,随着中主应力系数的增大,八面体剪应变随着八面体剪应力的增大而减小,而主应力轴往复旋转后定向剪切时,八面体剪应变随着中主应力系数的增大呈现先增大后减小的趋势;定向剪切应力路径下试样破坏时不同中主应力系数下的轴向应变、径向应变和环向应变均达到或超过4%,而主应力轴往复旋转下中主应力系数对轴向应变、径向应变和环向应变的影响不明显;定向剪切时的整体强度要高于主应力轴往复旋转后定向剪切的强度。In order to study the influence of the deformation and strength of the remolded saline soil under the three-dimensional complex stress state,the hollow cylindrical torsion shear apparatus was used to carry out the directional shear and the principal stress axis reciprocating rotation of the remolded saline soil under two stress paths.Research and analyze the development of octahedral shear stress-shear strain,as well as the change law of each strain component and strength.The research results show that under different intermediate principal stress coefficients,the shear stress required for specimen failure during shearing after the principal stress axis reciprocates is smaller than the shear stress required for directional shearing.During directional shear,the shear stress required for specimen failure is smaller than the shear stress required for directional shear.Increases,the octahedral shear strain decreases with the increase of the octahedral shear stress,and when the principal stress axis rotates back and forth and directional shear,the octahedral shear strain first increases and then increases with the increase of the intermediate principal stress coefficient Decrease trend;the axial strain,radial strain and hoop strain under different intermediate principal stress coefficients when the specimen is broken under the directional shear stress path all reach or exceed 4%,while the principal stress axis under the reciprocating rotation of the principal stress axis The coefficient has no obvious influence on the axial strain,radial strain and hoop strain;the overall strength during directional shear is higher than the strength of directional shear after the principal stress axis rotates back and forth.

关 键 词：重塑盐渍 土中主应力系数 定向剪切 主应力轴 往复旋转 

分 类 号：TU448[建筑科学—岩土工程]