Effect of cohesion, the friction angle and the time under static loading on the behavior of piles

The calibration chamber of the 3SR INPG laboratory in Grenoble used to study the point stress and the shear, mobilized along the shaft of the pile under monotonic axial loading. The physical model used for the various tests is a standard mini-pile installed in standard sand: Fontainebleau sand. This article explores the induced effects on the bearing shear capacity of the pile as a function of time, up to the point of failure, under different monotonic loads applied after periods of rest. A series of monotonic static loading tests, were performed on the pile. Tensile load tests, uplift, were performed before and after each series of static loads. A Lateral stress was observed at the start of the experiment at the pile-soil interface. It disappears as soon as the pile is driven into the soil, due to the dilatancy of the soil. This observed phenomenon is probably due to a decrease in non-mobilized lateral friction at the start of the experiment. A study of this phenomenon will be described in this article. Likewise, the effect of the mechanical characteristics of the soil and the effect of time will be presented in the bearing capacity of the soil, as well as the total bearing capacity of the pile under monotonic static loading.