颗粒破碎是粗粒土的基本属性。随着高土石坝的陆续兴建，高应力下粗粒土的颗粒破碎特征成为人们研究的一个重要方面。通过对不同粒径粗粒土试样的大型直剪试验，研究了高法向应力下粗粒土的颗粒破碎规律，并对接触面剪应力—剪位移关系进行了分析。结果表明：随着法向应力增加，颗粒破碎率增加；相同法向应力下，粒径越大，破碎率越大；级配越良好，破碎率越小；颗粒破碎主要形成次一级粒径。

Particle breakage is the basic property of coarse-grained soils.With the continuous construction of high earth-rock dams, the characteristics of particle breakage of coarse-grained soils under high stress are one of the important aspects for the particle breakage study. The large-scale direct shear tests were performed on the coarse-grained soils with different particle sizes to investigate the characteristics of particle breakage of coarse-grained soils under high normal stress, and the relationship between the shear stress and shear displacement at the interface was also analyzed. The results suggested that (1) with the increasing of normal stress, the particle breakage rate increases; (2) under the same normal stress, the particle breakage rate is higher when the particle size is higher; (3) the better the grading is, the lower the breakage rate is; and (4) the particle breakage mainly forms the sub-first grade particle size.

国家自然科学基金面上项目(50974091)；国家自然基金项目（51009103）