饱和层状砂土三轴液化试验

为了研究具有层状结构的饱和砂土液化时孔隙水压力的发展规律,利用GCTS-STX-050气动三轴测试系统对层状饱和砂土进行等幅应变控制下的液化试验研究,分析了试样中不同粉粒夹层厚度、位置及分布层数对液化影响.试验结果表明,试样液化所需的循环加载次数与粉粒夹层的厚度呈非线性关系,存在一临界厚度使得循环加载次数最大;粉粒层能够有效地阻碍细粒层产生的超孔隙水压力的传递,而细粒层对粉粒层产生的超孔隙水压力阻碍效果不明显;相同厚度下,粉粒夹层两层分布较一层分布对超孔隙水压力的阻碍作用更加明显.试验结论可为地震作用下具有层状结构的饱和砂土液化规律的探索提供一定的参考依据.

Triaxial Liquefaction Test of Saturated Stratified Sand

In order to study the developments of pore water pressure in the liquefaction processes of saturated sands with stratified structure, the liquefaction tests under equal amplitude strain control for saturated sands were carried out by using GCTS-STX-050 dynamic triaxial testing system. The effect of different thickness, position and number of layers on liquefaction was analyzed. It is showed that the cyclic loading times required for liquefaction is non-linearly related to the thickness of the silt interlayer. There is a critical thickness that causes the cyclic loading times to be maximum. And the silt can effectively prevent the transfer of excess pore water pressure generated by fine sand. But the inhibition of fine sand for excess pore water pressure generated by silt is not obvious. Under the same thickness of silt interlayer, the distribution of two-layered interlayer is more obvious than one layer on obstruction of excess pore water pressure. The conclusion can provide a reference for the liquefaction of saturated sand with stratified structure under earthquake.