关键词: 土石坝, 粗粒料, 旁压模量当量密度法, CT三轴仪, 微摩擦, 刚柔复合加载, 湿化变形, K-K-G剪胀模型

Abstract: China ranks top in the world in the amount of high earth-rock dam. To ensure the construction and long-term operation safety of high earth and rockfill dams is a major demand posed by national economic and public security. We summarize the major research progresses in the field of earth-rock dam engineering made by the Yangtze River Scientific Research Institute in recent years. Such progresses include: the test method of gradation similarity theory of coarse-grained material based on equalling density with pressuremeter modulus, the series CT triaxial apparatus for quantitatively measuring fabric of coarse-grained material, a novel friction reduction method in which the contact between soil and loading plate is changed from holistic contact to distributed contact and sliding friction to rolling friction, as well as its corresponding friction reduction devices. Moreover, true triaxial apparatus with large scale, high pressure, micro-friction and rigid-flexible composite loading has been developed. The variation law of strength and deformation and the wetting and creep deformation mechanism of coarse-grained materials under real three-dimensional stress have been revealed. The K-K-G nonlinear dilatancy model with three parameters, the wetting model with six parameters, the creep model with nine parameters and the corresponding parameter determination method have been established. In addition, in line with the original idea of equivalent density method, a test method for indirectly determining the field density of deep overburden with over 100 meters by pressuremeter test has been proposed. The above research findings offer crucial scientific and technological supports for the construction of high earth-rock dams.

Key words: earth-rock dam, coarse-grained material, equalling density with pressuremeter modulus, CT triaxial instrument, micro-friction, rigid-flexible composite loading, wetting deformation, K-K-G dilatancy model