强风化软岩用于路基填土时的工程特性研究

Study on Engineering Character of Embankment of Subgrade with Highly Weathered Soft Rock

强风化软岩用于高等级公路路基填土时,压实特性和湿化变形性能是评价填料性能的主要指标.通过对填料在不同压实度下的承载比(CBR)试验研究,结果表明,CBR值随填料压实度的增大而增大;利用室内三轴剪切仪,对强风化软岩进行干—湿双线平行试验和在复杂应力状态下不同压实度的湿化变形试验研究,结果表明,填料在压实度为90%时,在较大的偏应力作用下,湿化不仅产生较大的附加轴向应变,而且还能引起相当大的附加体变和偏应变.湿化使填土的强度降低,可见提高路基填土的压实度是减少湿化变形和提高路基边坡稳定性的重要途径.

When highly weathered soft rock used to fill high grade highway embankment, compaction character and wetting deformation character are major indicators to estimate the filling performance. The CBR experiments under different compaction degree showed that the CBR value increased with the filling compaction degree increasing. Triaxial shear apparatus was used to do dry-wet crewel parallel experiment and wetting deformation experiment of different compactions under complicated stress function. The result shows that when the compaction degree equals to 90 percent, under rather high deviatoric stress, wetting can not only generate high additional axial deformation, but also cause fairly high additional volumetric strain and deviatoric deformation. And wetting cause shear intensity of soil reducing. Increasing compaction degree of the filling is the key factor to decrease wetting deformation and to enhance slope stability of subgrade.