【摘要】 通过动三轴液化试验,提出了一个新的适用于非均等固结下饱和砂土孔压的增量型简化计算公式。首先,试验和分析表明,描述非均等固结对饱和砂土液化影响较为合适的方式是以kc-1的幂函数模式,建立非均等固结下孔压变化的相对增量?U/U 0与固结比的增量kc-1之间的关系,即?U/U 0=1,bC1,a(kc?1)C。系数C1,b是一个远小于1的数,表明孔压增量在kc接近1时降低速度较快,在kc继续增大时降低速度变慢并趋于平缓,而若采用kc幂函数,在1<kc<3则与孔压间近似成直线关系,不能很好描述这种变化;对本文中的两种砂,系数C1,a随密度增大而变小,变化在0.20~0.50之间,意味着kc=2时的孔压增量较kc=1时降低20%~50%。最后,试验与计算的对比表明,新公式不仅能描述等幅正弦荷载作用时不同固结比下饱和砂土的孔压增长,而且也能较好地描述随机地震荷载作用时非均等固结下饱和砂土的孔压增长过程。更多还原

【Abstract】 A new simplified incremental formula for evaluating the pore pressure of the saturated sands under the anisotropic consolidation was presented by using the dynamic triaxial tests.First,the test results indicated that the suitable form for describing the variation of the pore pressure due to the anisotropic consolidation was to use the power function of kc-1 to establish the relation between the relative increment of the pore pressure,?U/U 0,and the increment of the consolidation ratio,kc-1,i.e.,?U/U 0 =1,bC1,a(kc ?1)C.The coefficient C1,b was far away from 1,meaning that the pore pressure increment decreased rapidly when kc was near 1 and then decreased slowly.The power function of kc could not simulate the situation because in this case,the pore pressure increment was in nearly direct proportion to kc within 1<kc<3.The coefficient C1,a was 0.20-0.50 for two kinds of sands in the paper,which indicates that the pore pressure for kc=2 was 20%-50% less than that for kc=1.Finally,the comparison between the tests and calculations indicated that the new formula presented here could practically and effectively describe the rising of the pore pressure both for uniform and random loads.更多还原