沉积成层饱和粉土质砂振动孔压发展规律的试验研究

RESEARCH ON DEVELOPMENT RULE OF DYNAMIC PORE WATER PRESSURE IN SATURATED SILTY SAND OF SEDIMENT DEPOSITION

具有层状结构砂土的力学特性有别于纯净的砂土或含有一定细粒含量均匀混合砂土,利用自行制作的土样制备箱采用水中沉砂法制备沉积成层粉土质砂,通过动三轴液化试验研究这种沉积成层饱和粉土质砂的振动孔压发展规律。试验结果发现：对于沉积成层饱和粉土质砂,孔压一般达不到有效固结压力,仅为有效固结压力的70%~80%,而相应的轴向双幅应变可达到0.05左右;当围压为50 kPa时,其振动孔压发展模式可用反正弦函数表示;当围压为100,200 kPa时,其振动孔压发展模式都可用双曲线函数表示。

The mechanical properties of sand with layered structure is different from the pure sand or the mixed sand containing a certain content of fine particle .The study used the method of sand settling in water to prepare silty sand of sediment deposition in the self-made box, and investigated the law of development of dynamic pore water pressure in the saturated silty sand of sediment deposition through dynamic triaxial liquefaction test .The following conclusions were drawn from the test results：Dynamic pore water pressure could not reach the effective consolidation pressure of saturated silty sand of sediment deposition , it was only 70% -80% of effective consolidation pressure , but the corresponding double amplitude axial strain could reach 0.05;When the confining pressure was 50 kPa, its dynamic pore pressure model could be expressed by the arcsine function;When the confining pressure was 100 kPa and 200 kPa, its dynamic pore pressure model could be expressed by the hyperbolic function .