The mechanism controlling static liquefaction and cyclic strength of sand

Liquefaction and the cyclic strength of sand in undrained condition are strongly attached to the mechanisms observed in static tests. The cyclic failure condition, such as Cyclic Liquefaction and Cyclic Mobility is only part of the complex mechanism, which has to be determined in order to describe the development of stress and strain in cyclic tests. The key to explain and quantify the soil response is to understand the role of the volume changes and to be able to model these correctly. It is shown that the volume changes in soil subjected to static and cyclic loading are controlled by the characteristic line. Experiments have been performed to study the factors that influence the location of the characteristic line in drained and undrained tests for various types of sand and various types of loading. The relation of the characteristic line to other features of static, cyclic soil behaviour is explained and illustrated with experimental data.