【摘要】 从细观角度对砂土剪胀机理进行研究,通过简化提出一种简单的剪胀模型,推导结果表明孔隙比与主应力比有直接的关系,把所提出的剪胀模型与已有的剪胀机理相结合能够解释砂土的一些变形特性:密砂先剪缩后剪胀,并且无论多么密实的砂土都在加载初期出现剪缩现象;砂土越密实相变应力比越低,峰值应力比越高,剪缩过程越短,剪胀过程越明显;还可以解释卸载体缩、临界状态、相变状态等。模型可以解释砂土所具有的复杂的现象,有助于砂土剪胀(缩)机理的认识和理解。更多还原

【Abstract】 An approach is proposed to understand the stress-dilation mechanism of sands from the microcosmic point of view. The micromechanics of volume-contraction or volume-dilation is studied to form a direct relationship between the void ratio and stress ratio. Combining with other mechanics, some characteristics of sands during shearing can be explained, such as: dense sand contracting first and then dilating during shearing, no matter how dense the sand is; the denser the sand, the higher the peak stress ratio, the shorter the process of contracting, and the longer the process of dilating; volume-contraction in unloading, critical state and phase transformation state can also be explained.更多还原