加筋稻壳灰改性土动力特性研究

Dynamic characteristics of reinforced rice husk ash modified soil

为实现稻壳灰资源化利用,将稻壳灰加入土体中用于提高土体强度。对稻壳灰改性土开展了大型动三轴试验,分析了稻壳灰掺量、动应力幅值和加筋方式对稻壳灰改性土轴向累计变形、动应力−动应变曲线和动弹性模量的影响。研究结果表明:随稻壳灰掺量增加,稻壳灰改性土的最大干密度下降,最优含水率增加;稻壳灰掺量对土体性能有较大影响,在5%~10%稻壳灰掺量下,稻壳灰改性土轴向累计变形较低,土体强度较优;动应力幅值和加筋方式对稻壳灰改性土轴向累计变形影响明显。随循环次数增加,试样滞回圈面积减小,动弹性模量逐渐增加;加筋筋材可以提高土体性能,对于单层加筋,格栅加筋试样优于其他试样。

In order to realize the resource utilization of rice husk ash,rice husk ash was incorporated into the soil for improving the soil strength.Large-scale dynamic triaxial tests were carried out on rice husk ash modified soil.The effects of rice husk ash dosage,dynamic stress amplitude and reinforcement method on the cumulative axial deformation,dynamic stress-strain curve and dynamic elastic modulus of the rice husk ash modified soil were analyzed.The results showed that with the increase of rice husk ash content,the maximum dry density of rice husk ash modified soil decreases and the optimal moisture content increases.The content of rice husk ash has a significant influence on the performance of soil.Under the content of 5%−10%rice husk ash,the cumulative axial deformation of rice husk ash modified soil is low,and the soil strength is better.The dynamic stress amplitude and reinforcement method obviously influence the cumulative axial deformation of rice husk ash modified soil.As the number of cycles increases,the hysteresis loop area of the sample decreases and the dynamic elastic modulus increases gradually.Reinforcement materials can improve the performance of soil.For single-layer reinforcement scenario,grid reinforced soil samples surpass other samples in terms of performances.