Abstract
There exists a large class of crushable geomaterials with weak grains such as crushable ground. In order to research pile bearing capacity characteristics in crushable ground, the model pile tests have been carried out using two kind of crushable soil and Toyoura standard sand. To investigate the detailed characteristics of end bearing capacity acquired from the model pile test, soil particles were observed using oedometer test, sieve test and a microscope, following the model pile test. Samples of Chiibishi sand and Toyoura standard sand were sectioned and photographed.
Consequently, it became clear that the pile bearing capacity mechanism is greatly dependent on the grade of particle crushability. Various combinations of stress can exist in a soil adjacent to a pile and a given soil element could be subjected to any number of these during pile driving and final loading. For example the existence of large magnitude stresses at the tip. The mobilization of the strength of crushable soils requires a much higher strain level while at the same time the end bearing pressure on the model piles inducing considerable particle breakage. Foundation design methods can be safely used where stress levels or particle strengths prevent crushing. However, in the case of weak grains or high foundation stresses, consideration should be given to the effects of grain crushing. Also, the corresponding relation-ship of deformation of ground particles, pile bearing capacity, and particle crushability became clear.
