On the Permanent Depressions of Granular Materials under Static Repeated Loading

We carried out the laboratory model tests on the permanent depressions under static repeated loading (0-pkg/cm). Primary experimental conditions are as follows : The heights of the gravel layers are three kinds of 5,10,15cm and the diameters of gravels are 2-5mm, 5-10mm, and 10-15mm. The subgrade is made of concrete. We used wooden moulds (10×17cm, 13×22cm, 22×37.4cm) around the gravel layers and two kinds of loaded plates (7.5×12.75cm, 10×17cm.) Acting loads are 100,200,and 300kg. Some examples of the experimental results are shown in Fig. 1-fig. 3. In these cases the relationship between the permanent depressions and repeated intensities are generally expressed as follows : [numerical formula] (1) where, y=cumulative permanent depressions after n times repeating, p=mean load intensity, A, B= characteristic values of gravel layers, Determining the values of A and B from the experimental results we obtained the results as shown in Fig. 4-Fig. 7. We wish to proceed the experiments by changing the experimental conditions.