不同水环境下高分子材料改性粉土的试验研究

Experimental study on silty soil modified by polymer materials under varying water environments

针对粉土的不良工程特性,采用高分子材料对粉土进行改性。通过无侧限抗压强度、干密度与含水率的变化曲线确定其最优含水率;对最优含水率的改性粉土进行渗透试验、毛细水上升试验、抗冲刷试验以及干湿循环作用下强度特性试验。研究表明:①改性粉土渗透系数得到了明显的降低;②改性粉土毛细水作用得到了明显改善,毛细水作用的上升高度大幅度降低;③随降水时间的延长,试样质量损失呈递增的变化规律,但递增量很小,表明改性粉土有较好的抗冲刷能力;④随干湿循环次数的增加,强度衰减较弱,破坏应变与最大应力变化很小;⑤土经高分子材料改性后,有较好的水稳定性,适于粉土地区高速公路建设中,作为路基填土使用。

The silty soil is modified by polymer materials.Based on the relationship among unconfined compressive strength,dry density and water content,the optimum water content of the silty soil modified by the polymer materials is determined.In order to investigate the behaviors of the silty soil modified by the polymer materials with the optimum water content,the permeability tests,capillary water rising tests,anti-scour tests under varing precipitation time as well as strength characteristics test under wetting-drying circles are conducted.The test results are as follows：（1） the permeability coefficient greatly decreases due to being mixed with polymer materials;（2） the capillary water function is improved,and capillary water effect of lifting height greatly decreases;（3） with the increase of the precipitation time,the mass loss of soil samples increases;（4） anti-scour characteristics are good;and（5） the strength degradation is weak and the failure strain and the maximum stress both change very little with the increase of the wetting-drying cycles.The conclusion is that the silty soil modified by the polymer materials is of better water stability and is suitable to be used as subgrade fill for expressways in silt areas.