粗粒土在自然界中分布广泛且在工程中应用普遍,研究其力学特性具有重要意义。以原始土和添加30%碎石的改良土(碎石土)为研究对象,通过室内大型三轴剪切试验,研究提高含石量对粗粒土的抗剪强度和变形特性有何影响。试验结果表明:添加30%碎石后,粗粒土的透水能力增强,达到相同固结程度,所需时间更短;原始土和碎石土应力-应变曲线均表现出应变硬化特性;两种土的强度均随围压的增大而增大,且相同围压下,碎石土强度大于原始土,并且围压越大,差别越大;添加碎石提高了粗粒土的内摩擦角,但降低了粗粒土的黏聚力。Coarse-grained soil is widely distributed in nature and widely used in engineering, so it is of great significance to study its mechanical properties. In this study, the effects of increasing the stone content on the shear strength and deformation characteristics of coarse-grained soil were studied by using a large-scale triaxial shear test to study the original soil and the improved soil with 30% gravel (crushed stone soil). The test results show that after adding 30% crushed stone, the permeability of coarse-grained soil is enhanced, and the time required is shorter to reach the same degree of consolidation. The stress-strain curves of virgin soil and gravel soil showed strain hardening characteristics. The strength of the two kinds of soil increases with the increase of confining pressure, and the strength of gravel soil is greater than that of the original soil under the same confining pressure, and the larger the confining pressure, the greater the difference. The addition of crushed stone increases the internal friction angle of coarse-grained soil but reduces the cohesion of coarse-grained soil.
