循环荷载作用下纤维水泥土动力特性

Dynamic behavior of soil with fiber and cement under cyclic loading

通过动三轴试验,研究水泥土中掺入不同掺量的聚丙烯纤维和玄武岩纤维条件下,其动应力σ_d、动弹性模量E_d随动应变的变化规律。试验结果表明:水泥土的动强度和动弹性模量与围压、掺入纤维的种类和纤维掺量有关;随着纤维掺量的增多,水泥土的动强度和动弹性模量增大,动变形减小。从滞回曲线和微观的角度分析,掺入玄武岩纤维的水泥土动力性能最好,聚丙烯纤维水泥土次之,素水泥土(无纤维)较弱;最大动弹性模量E_(dmax)随着围压和纤维掺量的增大而增大。玄武岩纤维水泥土在不同围压下的E_d/E_(dmax)归一化曲线相互聚拢,表明E_d/E_(dmax)对围压的依赖程度降低。

The dynamic stress-strain and dynamic elastic modulus-strain of cemented soil mixed with different amount of polypropylene fiber or the basalt fiber were studied by using the dynamic triaxial apparatus. The results show that the dynamic strength and dynamic elastic modulus of cement soil is in connection with confining pressure, fiber types and fiber contents. With the increase of fiber contents, the dynamic strength and dynamic modulus of cemented soil increase, and the dynamic deformation decreases. The hysteresis curve and the microstructure of cemented soil show that the cement soil containing basalt fiber presents the best dynamic performance . The maximum dynamic elastic modulus Edmax increases with the increase of confining pressure and fiber content. The normalized Ed / Edmax curves of cemented soil mixed with basalt fiber under different confining pressures gather with each other, so the dependency on the confining pressure is weakened.