The Development Of Medium-sized Dynamic Triaxial Instrument And The Soil Dynamic Characteristics Of Municipal Solid Waste Pilot Study

The characteristics of deformation and strength of soil are often measured by triaxial test method in soil tests. But because the precision of conventional triaxial apparatus is 10-4, it can't measure accurately the relationships between stress-strain and the strength characteristic from 10-6-10-1. In this thesis, the medium scale dynamic triaxial apparatus, with micro strain measure technique, is developed to realize the aim.The thesis is divided into three parts. Firstly, the high precision triaxial apparatus is developed. By adopting local displacement transducers, gap sensors and an internal load cell, the precision of strain can be increased to 10-6. With multilevel displacement testing method, modulus and damping tests to some rockfill are executed by different control mode-force control and displacement control. It shows that the apparatus can advance the test precision, widen strain testing range and make the study of stress-strain of soil base on reliable tests.Secondly, cooperated with Zhe Jiang University, the dynamic deformation characteristics of municipal solid waste (MSW) are studied by dynamic triaxial test with two typical void ratios in landfill. It shows that void ratio has little effect on dynamic modulus and damping ratio of MSW, different with the other soils. The normalized equivalent elastic modulus curve is given in this thesis. The results can provide references to theory and engineering.Finally, the dynamic strength characteristics of MSW are also studied by triaxial tests. It shows dynamic strength of MSW are concerned to equivalent cyclic number and selection of failure strain. The results can provide references to aseismatic design of landfill in the future.