交通荷载下加筋砾砂动力特性研究

Study on dynamic characteristics of reinforced gravel sand under traffic load

为研究加筋对砾砂动力特性的影响,在多级长期循环荷载下无筋与加筋饱和砾性土动三轴试验的基础上,分析了加筋对饱和砾砂轴向塑性累积应变、回弹模量、体应变等动力特性的影响规律.试验结果表明:各级循环荷载下砾砂试样的塑性累积应变均呈现出加载前期(振次N≤100)骤然增长,然后逐渐平稳的发展模式.加筋能降低试样的塑性累积应变,提高砾砂的回弹模量.在循环动载作用下砾砂试样会出现体缩现象,且加筋试样的体缩现象更加明显.

In order to study the effect of reinforcement on the characteristics of gravel sand,a dynamic triaxial test was conducted under multistage and long-term cyclic loading on the saturated gravel with no reinforcement and the reinforced saturated gravel,and the influence of reinforcement on the dynamic characteristics of saturated gravel sand such as axial plastic cumulative strain,rebound modulus and bulk strain was studied.The experimental results show that the plastic cumulative strain of gravel sand samples under cyclic loading at all levels presents a similar development pattern that the plastic cumulative strain increases suddenly at the initial loading period(the number of vibrations is no more than 100),and then the development pattern is gradually stable.Reinforcement can reduce the plastic cumulative strain of the sample and improve the resilience modulus of the gravel sand.Gravel sand samples show bulk shrinkage under cyclic dynamic loading,and the bulk shrinkage of reinforced samples is more obvious.