黄河三角洲饱和地基土地震响应数值分析

Numerical analysis of seismic response of saturated foundation soil in Yellow River Delta

根据黄河三角地区特殊土层的力学性质,以天津波水平向加速度时程曲线为输入地震波,在3%,10%和63%三种超越概率情况下,对黄河三角洲20 m 深度土层的地震反应进行数值分析,研究了孔压和动剪应力的变化。与室内动三轴试验得到的破坏孔压和动剪应力进行比较,判断土层的液化破坏情况。研究结果表明,在3%超越概率下大部分地层均液化,在10%超越概率下少部分地层被破坏,在63%超越概率下大部分地层均不液化。采用破坏动剪应力比和破坏孔压比的判别结果相吻合。

Based on mechanical properties of the special soil layers in Yellow River Delta,with the horizontal acceleration time path of Tianjin seismic wave taken as the input seismic wave,numerical analysis is carried out on seismic response of the soil layers in the depth range of 20 m in Yellow River Delta.Three transcendental probabilities,i.e.3 percent,10 percent and 63 percent,are considered to study changes of pore water pressure and dynamic shear stress,which are compared with those obtained in laboratory dynamic triaxial tests to evaluate liquefaction potential of the soil layers.Research results show that under the transcendental probability of 3 percent,most of the soil layers will fail;under 10 percent,only a few will;and under 63 percent,most will not. Evaluation results obtained with failure dynamic shear stress ratio coincide with those obtained with pore water pressure ratio.