关键词: 粗粒土; 深厚覆盖层; 原位密度; 旁压试验; 大型三轴试验; 苏洼龙水电站;

Abstract: It is difficult to determine the in-situ physical properties of overburden coarse particles.In this study, the insitu densities and mechanical properties of coarse granular soils in the 3 rd and the 5 th deep overburden layers of dam foundation of the Suwalong Hydropower Station on the Jingsha River were investigated based on pressure meter model tests and large-scale triaxial tests.Firstly, according to insitu side modulus, we carried out pressure meter model tests in laboratory using two coarse granular soils with different densities from the same source, obtaining curves between pressure meter modulus and density, and further deducing the insitu densities of the 3 rd and the 5 th deep overburden layers.Based on the predicted densities of the two coarse granular soils, we carried out large-scale traxial tests in laboratory to obtain the strength and deformation parameters of the 3 rd and the 5 th deep overburden layers.The results can support dam safety analysis and deformation management of dam body.

Key words: coarse granular soil; overburden layer; insitu density; pressure meter test; large-scale triaxial test; Suwalong Hydropower Station;