ABSTRACT
Several examples of the collapse of foundation pits in the past had very serious consequences, which urged the people to study the design and construction of foundation pit deeply. At present the maintenance structure of foundation pit is designed and calculated by using the elastic foundation beam law or the elastoplasticity finite element method. The routine-test parameters generally were adopted as the computation parameters, which had not really considered the excavating and unloading to the influence of soilmass strength. The variation of soilmass strength after excavating and unloading is studied through the analysis of theory and test in this paper. The result of the study indicates that the unloading in excavation has influence on the variation of soilmass strength, which can be of some help to avoid project accidents.
