循环荷载作用下心墙掺砾土动应力应变孔压模型

摘要

Cumulative plastic deformation and development of the pore water pressure occurred in core gravelly soil under dynamic loading are of most importance for security of impervious core of dam.Based on Bouc-Wen smooth hysteretic model,considering hysteretic loop pinching effect and non-associative flow rule,a constitutive model is proposed to describe cumulative plastic strain and increasing pore water pressure of soil subj ected to cyclic loading.Cyclic triaxial tests for Nuozhadu's core gravelly soil under isotropic and anisotropic stress conditions have been carried out and dynamic stress-strain relationship and pore water pressure response are analyzed. By comparing the experimental and simulated curves,the presented model is proved to be reasonable and effective for describing dynamic stress-strain relationship of gravelly soil.%动力荷载作用下,心墙掺砾土的累积塑性变形和孔隙水压力的发展对心墙防渗体的安全至关重要.基于Bouc-Wen光滑滞回模型,考虑滞回圈捏拢效应,结合非关联流动法则,建立本构模型,模拟循环过程中土体产生的累积塑性应变和增长的孔压.通过糯扎渡心墙掺砾土均压固结和偏压固结状态的循环三轴试验,研究其动应力应变关系及孔压响应.将模型曲线与试验曲线进行对比分析,验证模型描述掺砾土动应力应变关系的合理性和有效性.