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由于降雨及蒸发的周期性变化等原因,压实地基土经常处于干湿交替状态,这种干湿循环作用会影响路基及地基的长期稳定性。通过气压式固结仪测试压实黄土试样经过不同次数干湿循环作用后的侧限压缩应变与垂直压力(ε_(si)-p_i)曲线,研究干湿循环作用对压实黄土变形特性的影响,同时利用已有模型对实测曲线进行拟合,并基于割线模量法分析了割线模量与初始压实度及干湿循环次数的关系。结果表明:初始压实度对黄土的压缩变形有显著影响,不同初始压实度的试样其各级压力下的侧限压缩应变均随着干湿循环次数的增大逐渐增加,之后趋于稳定;初始压实度越高,干湿循环作用影响效应越显著;干湿循环作用并不改变土体ε_(si)-p_i曲线的形式;割线模量与干湿循环次数及初始压实度的关系均呈指数关系。
Due to the periodic changes of rainfall and evaporation, the compacted soil often alternates between wet and dry conditions. This wetting and drying cycle will affect the long-term stability of subgrade and foundation. The compressive strain and vertical pressure (ε_ (si) -p_i) curves of compacted loess samples after different times of wetting and drying cycles were tested by air pressure consolidation tester to study the effects of wetting and drying cycles on the deformation characteristics of compacted loess At the same time, the existing models were used to fit the measured curves. Based on the secant modulus method, the relationship between the secant modulus and the initial compaction degree and the number of wet-dry cycles was analyzed. The results show that the initial compaction degree has a significant effect on the compressive deformation of loess. The compressive strain at different initial compresses increases with the increase of the number of wet and dry cycles, and then tends to The effect of wetting and drying cycles was more significant when the initial compaction degree was higher. The wetting and drying cycles did not change the form of soil ε_ (si) -p_i curve. The secant modulus and the number of wetting and drying cycles and the initial compaction The relationship between degrees are exponential.