冻融作用下木质素改良土的力学性能研究

1吉林建筑大学 交通科学与工程学院,长春 130118 2中交一公局公路勘察设计院有限公司,北京 100024

改良土; 三轴试验; 木质素; 峰值强度

Study on mechanical properties of lignin improved soil under freezing and thawing
MA Xin-yang1,DONG Wei-zhi1,XIA Lin-feng1,OUYANG Yun2

1 School of transportation science and engineering,Jilin Jianzhu university,Changchun 130118,China 2 CCCC highway survey & design Co.Ltd.of FHEC,Beijing 100024,China

improved soil; triaxial test; lignin; peak strength

备注

为了研究木质素用于季冻区路基土改良的效果,在最佳含水率,不同木质素掺量、不同养生龄期和不同冻融循环次数的条件下,进行不固结不排水的三轴压缩试验.结果表明,少量木质素的加入可以提高土体的黏聚力和内摩擦角,减弱冻融的影响.养生对于木质素改良土有积极意义,经过60 d养生后改良土的剪切峰值得到较大提升; 随着冻融循环次数的增加,素土和改良土剪切峰值减小,在12次循环后趋于稳定,相比较于素土,木质素改良土冻融损失率较小.本试验中使用的木质素应用于土体改良掺量可选择 6%,养生期可选择28 d.

In order to study the effect of lignin on subgrade soil improvement in permafrost regions,triaxial compression tests without consolidation and drainage were carried out under the conditions of optimum moisture content,different lignin content,different curing ages and different freeze-thaw cycles.The results show that the addition of a small amount of lignin can improve the cohesion and internal friction angle of soil and weaken the effect of freezing and thawing,and health preservation has positive significance for lignin improved soil,and the shear peak value of lignin improved soil is greatly increased after 60 days.with the increase of the number of freeze-thaw cycles,the shear peak value of plain soil and improved soil decreased and tended to be stable after 12 cycles,and the freeze-thaw loss rate of lignin-improved soil was lower than that of plain soil.In this experiment,the content of lignin used in soil improvement can be 6%,and the curing period can be 28 days.