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土体剪切带的形成与土体逐渐破损理论是当今国际力学界和岩土工程界十分关注的焦点。本文在结构性粘土三轴试验的基础上，首先讨论了剪切带形成的宏观力学条件及其倾角，接着借助于扫描电镜，并采用微观定量测试技术，对剪切带及其周围土体的微观结构进行了分析。结果表明：土体具有足够的结构强度是剪切带形成的条件之一，剪切带的倾角与Ｒｏｓｃｏｅ理论不相符；剪切带的厚度在宏观、微观上有差异；剪切带内外的土体，在孔径分布、孔隙比、定向度、各向异率等方面差别很大；剪切面上剪胀与剪缩并存，总体呈剪缩；带内土体亦强烈剪缩；土样宏观却呈轻微剪胀特性。这些成果既验证了沈珠江砌体理论，也为建立土体结构性指标，发展结构性模型及土体逐渐破损理论打下基础。
The formation of shear bands in soil and the theory of gradual failure of soil are the focus of attention in the field of international mechanics and geotechnical engineering. Based on the triaxial tests of structural clays, the macroscopic mechanical conditions and dip angles of the shear bands are first discussed. Then, the scanning shear electron microscopy (SEM) and microscopic quantitative testing techniques are used to study the shear zone and its surrounding soil. The microstructure was analyzed. The results show that the sufficient structural strength of the soil is one of the conditions for the formation of the shear band. The inclination of the shear zone does not agree with the Roscoe theory; the thickness of the shear zone varies in macro and micro conditions; the soil inside and outside the shear zone Body, in terms of pore size distribution, porosity ratio, orientation, anisotropy, etc., differ greatly; shear dilatation and shear shrinkage co-exist on the shear plane, and overall shear and shrink; soil within the band is also strongly sheared; soil sample macro However, it is slightly dilated. These achievements have not only verified the Shenzhu River masonry theory, but also laid the foundation for the establishment of soil structural indicators, the development of structural models, and the progressive failure theory of soil.