倾斜软弱地基上路堤的变形特征研究

基于强度折减有限元法,对倾斜软弱地基填方工程的基本特征进行了考察.对比分析表明:水平软弱地基填方工程中地基的侧向位移和竖向沉降基本以中心轴对称分布,而在倾斜软弱地基填方工程中不再按对称分布,明显向路堤下坡脚处快速发展,地基的倾斜对侧向位移的分布影响很大;随着路堤的分层填筑,路堤稳定性逐渐降低,到填筑结束时稳定性达到最小值,且倾斜软弱地基的稳定性明显小于水平软弱地基;与水平软弱地基的向两侧坡脚处破坏不同,倾斜软弱地基为沿地基倾斜方向向下滑裂破坏,具体破坏模式与软弱层的厚度有关.分析还表明,若需要对倾斜软弱地基进行加固,加固位置应位于侧向位移或位移增量为最大值处的下坡脚附近.

Study on the deformation behavior of subgrade embankments on inclined weak foundation

Based on the shear strength reduction FEM,deformation behavior of subgrade embankments on inclined weak foundation is studied.It is shown that the vertical settlements and the lateral deformation of embankment on horizontal weak foundation are symmetrically distributed along central axis,while that of inclined weak foundation is distributed inclined to the lower toe of embankment,indicating that the inclination of foundation has great influence on the distribution of lateral deformation specially.Stability of embankment decreases with increasing construction height of embankment,which get minimal value at the end of construction.On the same conditions,the stability of embankment on inclined weak foundation is obviously smaller than that of embankment on horizontal weak foundation.The results also show that the failure of embankment may occurr along the inclined surface of inclined weak foundation,different from the failure of embankment on horizontal foundation.The results also indicate that,if necessary,reinforcement should be laid out at lower toe of embankment on inclined weak foundation,where lateral deformation or incremental displacement vectors get its maximal value.