饱和粉土粉粒含量影响的动孔压发展规律试验研究

Experimental Study on Influence of Silt Particle Content on Pore Water Pressure Mode of Saturated Silt

采用多功能静动液压剪切三轴仪,进行大量不同粉粒含量的饱和粉土试验。通过试验研究了不同粉粒含量对饱和粉土振动孔压发展的影响。试验在达到液化标准后继续施加动荷载,使试验结果能够模拟液化破坏严重情况下的孔压发展的完整过程。研究结果表明,不同粉粒含量的粉土其孔压发展可以用同一个改进指数函数表达式来表示,该表达式包含2个参数a,b。粉粒含量的影响主要体现在系数b上,系数b随着粉粒含量的增加而单调增加;而系数a则基本不受粉粒含量变化的影响。结果表明由该模式得到的理论值与试验值拟合得较好。

In order to study the effect of silt particle content,a series of dynamic cyclic tests of saturated and disturbed silt were conducted in a new universal triaxial torsional shear apparatus of Hohai University. The tests didn＇t stop until the pore water pressure developed to a smooth way. It can simulate the whole process for pore pressure development from initial liquefaction to the serious liquefaction degree. Based on the tests results, a special regulation called expression （1） was proposed. The expression （1） consists of two parameters, a and b. One of the two parameters b in expression （1） reflects the silt particle effect on pore water pressure development. Coefficient b increases with silt particle content while another coefficient a keeps constant. The results indicate that the theoretical value by the expression agrees well with the test data.