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为研究淤泥质砂土的动力特性,利用动三轴仪对现场饱和淤泥质砂土进行不同固结应力状态下(固结围压σ3c=100,200,300,400 kPa,固结应力比Kc=1.0,1.5,2.0)的动力变形特性及动强度特性试验研究。分析动应力–动应变关系,阻尼比、动强度等一系列变化规律,并对淤泥与砂含量比例对淤泥质砂土动力特性的影响进行初步探索。研究结果表明:固结应力状态对饱和淤泥质砂土动应力–动应变关系影响很大;阻尼比随动应变的增大而增大,相同固结围压下,阻尼比随固结应力比的增大而增大;不同固结应力状态下,动应力随破坏振次的增大而降低,相同固结应力比,不同固结围压下σd/(2σ3c)与fN关系可以近似归一;不同的淤泥含量对饱和淤泥质砂土的动力特性影响显著,在相同的动应变条件下,动应力随着淤泥含量的增大而减小;在相同的固结围压下,阻尼比随着淤泥含量的增大而增大;强度并不是随着淤泥含量的增加而单调增加,在淤泥含量为20%时强度最低。
In order to study the dynamic characteristics of silt sand, the dynamic triaxial apparatus was used to test the saturated silty sand at different consolidation stress conditions (consolidation confining pressure σ3c = 100,200,300,400 kPa, consolidation stress ratio Kc = 1.0,1.5,2.0 ) Dynamic deformation and dynamic strength of the experimental study. The dynamic stress-dynamic strain relationship, damping ratio and dynamic strength were analyzed. The influence of the ratio of silt to sand on the dynamic characteristics of silty sand was also discussed. The results show that the consolidation stress state has a great influence on the dynamic stress-strain relationship of saturated silt sand. The damping ratio increases with the increase of dynamic strain. Under the same consolidation confining pressure, the damping ratio increases with the consolidation stress ratio The dynamic stress decreases with the increase of failure frequency under different consolidation stress. The relationship between σd / (2σ3c) and fN under the same consolidation stress ratio and different consolidation confining pressure can be approximated by the same ; Different silt content has a significant impact on the dynamic characteristics of saturated silt sand, under the same dynamic strain, the dynamic stress decreases with the increase of silt content; with the same consolidation confining pressure, the damping ratio The content of silt increases and increases; the intensity does not monotonically increase with the increase of silt content, and the lowest strength when the content of silt is 20%.