摘要
通过野外崩积混合体结构特征分析,考虑原样级配,开展对崩积混合体重塑样的室内大尺度直剪试验研究,结合PFC2D颗粒离散元仿真试验,分析了不同含石量情况下崩积混合体变形与强度变化规律及内在机理。将数值试验的成果与室内试验结果进行对比分析。结果表明,随着含石量的增加,崩积混合体的应变硬化效应显著。低法向应力下崩积混合体表现为剪胀,高法向应力下则表现为剪缩;当含石量低于40%时,崩积混合体的力学性质由土体控制,超过80%以后,其力学性质基本上完全由块石控制。
Large scale direct shear tests on remolded colluvial mixture samples were carried out in laboratory on the basis of gradation analysis. The deformation and strength characteristics of colluvial mixture with different rock particle contents were studied combined with simulation by two dimensional particle flow code PFC2 D. By synthesizing the numerical and testing results, it is concluded that the colluvial mixture with higer content of rock particle behaves strain hardening. Colluvial mixture samples exhibit shear dilatation characteristics at low normal stress level, and tend to have shear contraction at higher stress level. If the rock particle content is less than 40%, the mechanical characteristic of colluvial mixture is controlled by soil; while this content is greater than80%, its mechanical characteristic is influenced by rock alone.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2014年第S2期587-592,共6页
Rock and Soil Mechanics
基金
国家自然科学基金(No.40772179
No.41072206)
关键词
崩积混合体
直剪试验
颗粒离散元
变形
抗剪强度
colluvial mixture
direct shear test
particle flow code
deformation
shear strength
