等应变循环加载下饱和含砾砂土的液化特性

Liquefaction characteristics of saturated gravelly soils under isostrain cyclic loading

随着越来越多的砾性土地震液化现象发生,砾性土的液化特性问题成为了研究热点。为了研究砾性土液化特性,根据质量比制备出含砾量分别为0%、10%、20%和30%共四种含砾砂土,然后依据水中砂雨制样法重塑含砾砂土试样;采用等应变幅控制下动三轴仪分析含砾量、初始有效围压、轴向应变幅值对含砾砂土的液化特性影响。结果表明,含砾量和初始有效围压的增加,使得含砾砂土试样液化所需振次变多,表明其抗液化能力增强;而轴向应变幅值的增大使得含砾砂土试样液化所需振次减少,当轴向应变幅值大于1.67%时逐步趋于稳定。

With the occurrence of more and more seismic liquefaction of gravelly soils,the liquefaction characteristics of gravelly soils become a research hotspot.In order to study the liquefaction characteristics of gravelly soils,four kinds of gravelly soils with gravel content of 0%,10%,20% and 30% are prepared according to the mass ratio,and then the gravelly soils’ samples were remolded according to the soil rain sampling method in water.The effects of gravel content,initial effective confining pressure and axial strain amplitude on the liquefaction characteristics of gravelly sand were analyzed by dynamic triaxial apparatus under the control of equal strain amplitude.The results show that the increase of gravel content and initial effective confining pressure increases the number of vibration times required for liquefaction of gravel soils’ samples,indicating that their anti liquefaction ability are enhanced.And,the increase of axial strain amplitude reduces the vibration times required for liquefaction of gravelly soils’ samples,and gradually tends to be stable when the axial strain amplitude is greater than 1.67%.