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为探讨黄土动力特性受加筋方式的影响,利用GDS动态三轴测试系统,以玻璃纤维单丝窗纱为筋材,开展了4种围压下10种不同加筋方式的黄土动力特性试验,研究了黄土动弹性模量和阻尼比随围压、加筋位置、加筋层数的变化规律。结果表明:未加筋和加筋试样动弹性模量都随动应变增加呈指数衰减,但随围压增加而增大;应变小于0.05%时,阻尼比分布较离散,应变大于0.05%时,阻尼比随围压和动应变增加而增大;筋材的加入提高了土样的动弹性模量,并有效降低了阻尼比。通过构建加筋效用规格化系数并对比发现:加筋效益受围压与动荷载传播方向影响最为显著;中等围压下筋材发挥效益最明显;对本试验土样尺寸而言两层加筋效果较佳;动静荷载作用下土体中筋材布置都应优先考虑土样2/3~3/4附近。
In order to investigate the dynamic characteristics of loess reinforced by the way of reinforcement, using GDS dynamic triaxial test system, fiberglass monofilament screens were used as reinforcement to carry out four dynamic tests of loess with ten different reinforcement methods under confining pressure The law of elastic modulus and damping ratio of loess with the change of confining pressure, reinforcement location and reinforcement layer was studied. The results show that the dynamic modulus of both un-stiffened and stiffened specimens decreases exponentially with the increase of dynamic strain, but increases with the increase of confining pressure. When the strain is less than 0.05%, the distribution of damping ratio is more discrete. When the strain is greater than 0.05% The damping ratio increases with the increase of confining pressure and dynamic strain. The addition of reinforcement material increases the dynamic elastic modulus of soil samples and effectively reduces the damping ratio. Through the construction of the normalized coefficient of reinforcement effectiveness and comparison, it is found that the reinforcement effect is most significantly affected by confining pressure and dynamic load propagation direction; the reinforcement material with medium confining pressure has the most obvious benefits; and the two-layer reinforcement effect Better; soil material should be given priority to soil near 2/3 ~ 3/4 under static and dynamic load.