循环荷载下郑汴物流通道粉土路基的液化特性

Dynamic characteristics analysis of Zheng-Bian logistics channel silty soil based on dynamic triaxial test

在高等级公路和市政道路的建设中,如果遇到特殊地基处理不当往往会导致强度问题和沉降变形问题,影响道路的正常使用.鉴于此,利用动三轴进行室内试验,分析郑汴物流通道的路基施工过程中土体变化的规律.试验采用美国GCTS公司生产的STX-200双向动三轴仪进行,建立循环荷载次数、荷载频率、围压、轴压、偏应力等影响因素的郑汴物流通道软土路基的液化特性研究.试验结果表明,低频循环动载下土体的应力-应变曲线变化幅值小,高频循环动载下土体应力下降快且变化幅值大;随着循环次数增加,土体的孔隙水压上升加速,有效平均压应力减小幅值逐渐增大;粉土试样孔隙水压力变化随循环次数的变化而变化.

In the construction of highway,the normal usage will be influenced by complex subgrade.In this study,the STX-200two-way vibration dynamic triaxial apparatus is used to conduct dynamic triaxial tests on silty soil samples taken from the Zheng-Bian logistics channel in the city of Zhengzhou.And then,the liquefaction characteristics of the soft soil subgrade of the Zheng-Bian logistics channel are analyzed considering the influence factors such as the cyclic loading time,loading frequency,confining pressure,axial pressure,deviatoric stress,etc.The experimental results indicate that：Under a cyclic dynamic loading of low frequency,the amplitude of the soil＇s stress-strain curve experiences only minimal change.Additionally,when the cycle time is lengthened,the pore water pressure of the soil rises;and the diminished amplitude of the effective average compressive stress gradually increases.Therefore,the pore water pressure of the silty soil sample changes along with changing cycle times.