摘要
受扰动后土体抗剪强度常发生衰减,从细观尺度探讨了黏土细观参数与动后强度指标的关系。发现扭剪和单剪对土体静强度影响显著,稳定后强度折减范围在20%～50%,但仍然高于重塑土静强度。随着扰动次数增加,黏聚力与内摩擦角均表现出前期迅速衰减,之后放缓并稳定的趋势。选取了5种典型细观参数进行分析,发现扭剪作用下,土体纵断面与横断面孔隙数增长率相近;单剪作用下,由于径向平面内不存在切应变,横断面的孔隙增长率将小于纵断面。随着细观土颗粒数的增加,黏聚力首先线性下降,之后稳定在较低水平;而内摩擦角未呈现收敛趋势。
Dynamic loading tests and mesoscopic tests were carried out to study the correlation of strength indices and mesostructure parameters, which commonly degrades for disturbed structural clay. It is found that cyclic torsional and simple shears cause a remarkable strength degradation for structural clay, in the range from 20% to 50%. The strength of silty clay after external disturbance is still greater than that of the reconstituted silty clay. Cohesion and friction angle of the disturbed silty clay degrade dramatically and then decrease to a stable value with the increasing of disturbance times. The investigation of five typical mesostructure parameters show that the growth rate of void for transverse sections subjected to the torsional shears is similar to the longitudinal profile. However, the void growth of longitudinal profile is greater than the transverse value subjected to simple shears. There is a linear attenuation between post-disturbance cohesion ratios and void number at the early period, and then the cohesion will become a constant value. By contrast, there is no convergence between friction angle ratios and void number ratios.
作者
霍海峰
雷华阳
冯兴
王新强
闫晓荣
HUO Hai-feng;LEI Hua-yang;FENG Xing;WANG Xin-qiang;YAN Xiao-rong(School of Airport Engineering,Civil Aviation University of China,Tianjin 300300,China;School of Civil Engineering,Yianjin University,Tianjin 300072,China;Tianjin Tianyi Construction Group,Tianjin 300300,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2018年第11期3949-3956,共8页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.51308534
No.51378344)
中央高校基金B类项目(No.3122014B003)~~
关键词
饱和黏土
强度衰减
细观参数
孔隙数量
saturated clay
strength attenuation
microstructure parameter
void number
