针对高液限土通过掺灰改良应用于路堤填筑方面的理论不足,对掺灰改良前后土体性能进行了试验研究。采用界限含水率试验、自由膨胀率试验和无荷膨胀试验、干湿循环下改良土的水稳定性试验,对高液限土改良前后、不同灰剂量、不同养护时间下的力学性质、变形和稳定性方面的变化进行研究。研究表明,灰剂量4%、养护7-14天时,其液限及塑性指数下降明显。石灰改良土无荷膨胀率明显低于素土无荷膨胀率,且灰剂量4%、养护7天时,其膨胀率降低效果最好。干湿循环作用下,素土很快崩解,而石灰改良土则随着灰剂量增大,其膨胀现象越是推后且不明显。改良土的CBR值先随循环次数的增加而增大,后渐趋平稳,2%和4%灰剂量的循环到一定次数之后有所降低。
Aimed at the theory lackness of high liquid limit soil’s application in embankment filling ,the test and study are carried out for the soil properties before and after mixing with lime .Through the limit moisture content test ,expansion ratio test and water stability test under dry-wet circulation ,the physical and mechanical properties and the changing regu-lations of the mixed soil under different ash dosage and curing time are studied .The main results show that under the lime dosage of 4% and 7~14 curing days ,both liquid limit and plastic index have obvious decline ;the mixed soil’s expan-sion ratio is significantly lower than that of plain soil ,and the achieved effect is best in the lime dosage of 4% and curing time of 7 days;with the dry-wet circulation ,the plain soil collapses soon ,while the mixed soil’s expansion occuers later and is not obvious with the increase of lime dosage ;the mixed soil’s CBR value first increases with the cycle times ,then gradually levels off ,and under the lime dosage of 2% and 4% ,tends to decrease after certain cycle times .