【摘要】 本文通过室内三轴试验研究冻融作用下边坡表层粉质粘土土体随含水量、密实度、冻融次数、是否存在植物根系等不同条件下土的力学指标变化规律,对提高季冻区边坡防护效果具有一定的理论指导意义。研究结果表明:(1)土体主应力差在植物根系作用下明显提高,在含水率13%左右提高明显;加根土主应力差随土的密实度增加而显著提高。(2)含水率较小时,土体黏聚力随含水率的增加而增大,当含水率在13%左右时,黏聚力最大,当含水率大于13%后,黏聚力开始随含水率增加而减小。植物根系作用下粘聚力随土体密实度增加而增大。(3)随含水率增加土体内摩擦角减小,含水率越大内摩擦角减小幅度越大。含水率较大时植物根系对土体内摩擦角影响较小;含水率较小和密实度较大时植物根系对提高土内摩擦角作用明显。更多还原

【Abstract】 In this paper,through indoor triaxial test the soils mechanics index variation laws of slope surface layer silty clay under the action of freezing and thawing with different water content,compactness,freezing and thawing times,plant roots were analyzed,which has a certain theoretical guiding significance for the improvement of the effect of slope protection in seasonal frozen area.The results showed that:( 1) The difference of principal stress of soil under the effect of plant root system increased significantly,and the increase was obvious at 13% moisture content; The principal stress difference of the plant roots soil increased significantly with the increase of the compactness of soil.( 2) Under low moisture content,soil cohesion increased with the increase of moisture content,and reached the maximum at moisture content of around 13%. When moisture content was more than 13%,the cohesion began to decrease with the increase of moisture content. Plant roots under the action of cohesive force increased with increasing soil compactness.( 3) With the increase of moisture content,the angle of internal friction of soil was reduced,the greater the moisture content the greater the decrease amplitude of the angle of internal friction. When soil moisture content was larger the plant roots had little effect on the internal friction angle. When the moisture content was smaller and the compactness was larger,plant roots had obvious effect in improving the soil angle of internal friction.更多还原