饱和砂土循环液化模式影响因素试验研究

Experimental Study on Influencing Factors of Circulating Liquefaction Model of Saturated Sand Soil

通过室内试验探讨了振动频率、骨架相对密实度、填料含量及成分对砂土循环液化强度及液化模式的影响。针对相对密实度分别为35%、50%和80%的砂骨架中添加0%、5%、8%、10%、15%和20%等不同质量的填料(粉土、粉质黏土)进行了循环扭剪试验,循环加载频率为0.1、1 Hz。结果表明:砂土循环液化模式与振动频率密切相关,振动频率较高时,呈现显著的软化特征和流滑现象,振动频率较低时,呈现剪胀和循环活动性;循环液化模式与骨架相对密实度密切相关,填料含量及填料成分对动强度具有较显著的影响,但填料含量在一定范围内并不影响循环液化模式,填料成分对循环液化模式产生一定影响。

The effects of vibration frequency,skeleton density,fines content and composition on cy‑clic liquefaction strength and liquefaction mode of sandy soil are discussed through laboratory tests.The cyclic torsional shear tests were carried out for sand skeleton with 35%,50%and 80%compact‑ness,adding 0%,5%,8%,10%,15%and 20%fine grains(silt and silty clay)of different quality.cyclic loading frequency is 0.1Hz and 1Hz.The experimental results show that the cyclic liquefaction mode of sandy soil is closely related to the vibration frequency.When the vibration frequency is high,the liquefaction mode presents obvious softening characteristics and slippery phenomena.When the vi‑bration frequency is low,the liquefaction mode presents dilatancy and cyclic activity.The cyclic lique‑faction mode is closely related to the skeleton compactness,and the content and composition of fine particles have significant effects on the dynamic strength.However,the content of fine particles does not affect the cyclic liquefaction mode in a certain range,and the composition of fine particles has a certain impact on the cyclic liquefaction mode.