车辆荷载作用下路基填料动力特性研究

Study on dynamic characteristics of subgrade filler under vehicle load

通过GDS循环三轴仪,从影响公路路基填料的细粒含量、动偏应力及荷载频率3个因素出发,对其在动力作用下的试样动力特性进行了实验研究。研究表明:当粗粒填料处于高循环动应力及高频率作用下时,其路基粗粒填料更容易出现孔压累积现象,导致粗粒路基在长期交通荷载作用下不能达到稳定状态,出现破坏;细粒含量的增加对于粗粒土体应变的影响存在一个最优值。在实验中,3%的细粒含量时,粗粒试样的体应变达到最大;超过3%后,其体应变开始减小;循环作用的动偏应力较小时,粗粒填料的回弹模量会随着加载频率的增大而增大。但当细粒含量为6%时,在3Hz作用下的试样会因为土体的孔压累积,导致回弹模量出现减小。其研究成果为类似工程提供借鉴。

Based on the three factors affecting the fine particle content,dynamic deviatoric stress and load frequency of highway subgrade filler,the dynamic characteristics of the sample under dynamic action are experimentally studied by GDS cyclic triaxial apparatus.The research shows that when the coarse-grained filler is under the action of high cyclic dynamic stress and high frequency,the pore pressure accumulation of the coarse-grained subgrade is more likely to occur,resulting in the failure of the coarse-grained subgrade under long-term traffic load;There is an optimal value for the effect of the increase of fine content on the strain of coarse-grained soil.In the experiment,when the content of fine particles is 3%,the volume strain of coarse-grained samples reaches the maximum,and when it exceeds 3%,the volume strain begins to decrease;When the cyclic dynamic deviator stress is small,the resilient modulus of coarse-grained filler will increase with the increase of loading frequency.However,when the fine particle content is 6%,the rebound modulus of the sample under the action of 3Hz will decrease due to the accumulation of pore pressure of the soil.The research results can provide reference for similar projects.