以多组人工调制的不规则正弦波荷载作为输入荷载,对饱和松砂开展一系列动三轴试验,探讨应力时程中不同脉冲幅值和脉冲顺序对砂土孔压特性的影响。试验结果表明,出现更早、幅值更大的应力脉冲更易导致孔隙水压力的发展,同时也更易诱发砂土液化。进一步地,峰值应力之前和之后的脉冲波组对孔压发展的影响有所不同。此外,不同荷载模式下,饱和松砂动孔压比与振次比存在近似唯一关系。根据砂土孔压特性,引入单位体积剪切功并考察其与超静孔压的内在关联,得到了孔压比与正交化剪切功的归一化关系。这一关系具有应力路径无关性,受动荷载不规则性影响较小,但与材料特性即土体种类有关。 A series of triaxial tests on saturated loose sand were carried out by using a plurality of randomly modulated sine wave loads as input loads. The effects of different pulse amplitudes and pulse sequences on the pore pressure characteristics of sand were investigated. The experimental results show that the occurrence of earlier, larger amplitude of the stress pulse is more likely to lead to the development of pore water pressure, but also easier to induce sand liquefaction. Further, the influence of the pulse wave group before and after the peak stress on the pore pressure development is different. In addition, under different loading modes, there is an approximate and unique relationship between the moving pore pressure ratio and the vibration frequency ratio of saturated sands. According to the sand pore pressure characteristics, the unit volumetric shear force is introduced and its internal relationship with the excess pore pressure is investigated. The normalized relationship between pore pressure ratio and normalized shear force is obtained. This relationship has the stress path independence, less affected by the dynamic load irregularity, but with the material properties that soil types.