基于FLAC3D路基模型的路基土动力响应及压实度变化规律研究

Study on Dynamic Response of Subgrade Soil and Change Rule of Compaction Degree Based on FLAC3D Subgrade Model

为探析地震荷载作用下压实度对路基土动力响应的影响,文中利用FLAC3D模拟软件建立路基模型,分析地震荷载作用下压实度对路基土动力响应的影响。结果表明,竖直方向的位移、速度、加速度放大系数均随压实度的增加而减小,水平向放大系数与压实度关系反之。当压实度增加1%时,垂直向位移放大系数减小0.48、速度放大系数减小2.57、加速度放大系数减小11.8;水平向位移放大系数增加1.8、速度放大系数增加0.8、加速度放大系数减小0.4。总之,应分别采取路堤中加筋及提高压实度的措施限制路基水平及竖直向地震响应。

In order to investigate the effect of compaction degree on dynamic response of subgrade soil under seismic load,a subgrade model was established by FLAC3D simulation software to analyze the effect of compaction degree on dynamic response of subgrade soil under seismic load.The results show that the vertical amplification coefficients of displacement,velocity and acceleration decrease with the increase of compaction degree,while the horizontal amplification coefficients are inversely related to compaction degree.When the compaction degree increases by 1%,the vertical displacement amplification coefficient decreases by 0.48,the velocity amplification coefficient decreases by 2.57,and the acceleration amplification coefficient decreases by 11.8.The horizontal displacement amplification factor increases by 1.8,the velocity amplification factor increases by 0.8,and the acceleration amplification factor decreases by 0.4.In conclusion,measures to strengthen embankment and increase the degree of compaction should be taken respectively to limit the horizontal and vertical seismic response of subgrade.