不同应力路径及颗粒级配下青岛海砂试验研究

Study of Sand Mechanical Behavior With Different Grain Distribution under Different Stress Path

进行青岛海砂在不同应力路径下的三轴试验.利用GDS三轴试验系统,得到青岛海砂的应力-应变曲线,分析青岛海砂在不同应力路径下力学响应的细观机理.分别探讨了标准三轴路径、等p路径、被动压缩路径、等主应力比路径下青岛海砂的力学性质.将不同应力路径下青岛海砂的应力-应变曲线进行对比,分析不同应力路径和颗粒级配对青岛海砂力学性质的影响.标准三轴路径下青岛海砂的峰值强度最高,等p路径下次之,被动压缩路径下最低;被动压缩路径下体应变值最大,等p路径次之,标准三轴试验最小.这说明随着围压的增大,砂土强度值逐渐增大,体应变值会逐渐减小.颗粒级配对峰值强度有一定影响,但对剪胀量的影响不明显.

The laboratory triaxial tests of Qingdao sea sand under different stress paths are carried out. The stress-strain curves of Qingdao sea sand are obtained by using the GDS triaxial system, and the micro mechanism for the mechanical response of Qingdao sea sand under different stress paths is analyzed. Probe into the mechanical behavior under standard three axis test, constant p, reduced triaxial and the principal stress ratio stress paths. The stress-strain curves under different stress paths are contrasted and the effect of stress paths and grain distribution on menchanical behavior of Qingdao sea sand is analyzed. The peak value strength under standard three axis test path is the greatest, the constant p is in the middle, and the reduced triaxial is the lowest. But the reduced triaxial has the greatest volumetric strain, the constant p is still in the middle and the standard triaxial has the lowest volumetric strain, which indicates that the peak strength value is increased with confining pressure but the volumetric strain is decreased with confining pressure. Grain distribution has some effect on peak strength value, but has little obvious effect on volumetric strain.