冻融循环对粉煤灰土动强度的影响

根据粉煤灰土和粉质黏土经过冻融循环后动强度的对比试验,对粉煤灰土和粉质黏土的动强度做出了定量分析。试验发现,冻融循环影响粉煤灰土的强度特性,经过1次冻融循环后,粉煤灰土的强度明显降低,但是粉煤灰土的动强度下降率低于粉质黏土的下降率。随着冻融循环次数的增加,粉煤灰土的动强度逐渐衰减,经历4~5次冻融循环的粉煤灰土的动剪强度趋于稳定,且高于粉质黏土,在季节性冻土地区可以减轻公路的冻害。

Effect of freeze-thaw cycles on dynamic strength of fly ash soils

On the basis of the results obtained from comparison tests of fly ash soils and silty clay on dynamic strength under freeze-thaw cycles,the dynamic strength was quantitatively analyzed.The test results show that the effect of freeze-thaw cycles on the dynamic strength of fly ash soils should be considered.After 1 freeze-thaw cycle,the dynamic strength of fly ash soils decreased greatly,but its decreasing rate is lower than that of silty clay.The dynamic strength of fly ash soils gradually decreases with increasing the number freeze-thaw cycles.After 4~5 cycles,its strength reaches stability,and the dynamic strength of fly ash soils is still higher than that of silty clay.Thus fly ash soils can be used to weaken the freezing damages on highways.