珊瑚砂抗剪强度及颗粒破碎影响因素试验研究OA北大核心CSTPCD

Coral sand is brittle and easily broken,and its mechanical and deformation properties are different from those of quartz sand.To study the influence of particle size and precompression on the shear strength and particle breakage of coral sand,the confined compression test and triaxial shear test are carried out on coral sand samples.The mechanical and deformation properties of coral sand-quartz sand mixture in triaxial shear state are discussed.The results show that the crushed coral sand particles are mainly concentrated in the particle size one level smaller than the original particle size.The smaller the initial particle size is,the more obvious the particle clusters are.The particle size has a great influence on particle breakage,especially when the particle size of coral sand is larger than 1 mm.The particle size of coral sand after crushing is mainly greater than 0.25 mm.Precompression(particle breakage)will lead to the increase of coral sand internal friction angle.The addition of quartz sand has little effect on the internal friction angle.Both precompression and the addition of quartz sand will reduce the apparent cohesion,and the more the content of quartz sand is,the more the apparent cohesion decreases.Precompression,increasing the content of quartz sand and increasing the particle size will reduce the degree of particle clusters and increase the degree of particle breakage.