Abstract: In order to investigate the regulation of pore water pressure of silty soils, a series of dynamic cyclic tests on saturated and disturbed silt were carried out in a new universal triaxial torsional shear apparatus of Hohai University. The special was that the tests didn’t complete when the initial liquefaction appeared until the pore water pressure had been in a smoothly way, which could simulate the severity of liquefaction after liquefaction and also describe the whole process of pore water pressure generation. It is found that the regulation of pore water pressure curve can be fitted by an improved exponential function. The function can fit much achievements of other scholars and also make up the limitation that pore water pressure is larger than confining pressure. Both theoretical analysis and test data validation indicate the applicability of the pore water pressure expression.

Key words: silt, pore water pressure, model, dynamic triaxial test