超径颗粒粒度效应对基底材料力学特性的影响

Effect of Gradation of Coarse Grains on the Mechanical Properties of “Based-type” Granular Materials

本文对“基底型”颗粒材料中超径颗粒含量、颗粒粒径、基底土干容重以及试验围压4个因素对其力学特性的影响进行了大量的室内三轴试验,获得了各影响因素的定量参数。通过对试验成果的分析,着重探讨了基底型颗粒材料中超径颗粒粒径和含量两个因素对其强度变形特性的影响规律及其力学机理,提出了用单位剪切线上的超径颗粒数目这一特征指标来综合反映超径颗粒尺寸和含量对基底材料强度特性的影响效应。并进一步对试验中所观测到的一个重要的物理现象—基底型颗粒材料变形形态的分叉现象,进行了理论分析。

A series of triaxial tests have been conducted to study the effect of coarse grain percentage and size, dry density of based soil and confining pressure on the mechanical properties of 'based-type' granular materials. The rule and mechanism of the effect of size and contents of coarse grains on the strength and deformation characteristics of field materials are mainly discussed according to the test results. It is put forward that this effect can be reflected comprehensively by the index-the number ofcoarse grains per unit length on the shear line. Bifurcation of deformation state of test specimens caused by coarse grains is analysed theoretically.