Resumen
The behavior of horizontally loaded bored piles in a collapsible soil was studied. Experimental investigation comprised four horizontal load tests performed on two piles at each time, located at the Experimental Foundation Field at the State University of Londrina, Paraná, where the soil profile shows a superficial layer of collapsible clay. Horizontal load tests were performed for two soil conditions: natural (not wetted) and 48 hours pre-wetted. Ultimate and collapse loads, obtained in these conditions, produced a better understanding of the influence of soil collapsibility in the reduction of the piles' bearing capacity. Load test data also produced curves of horizontal coefficient subgrade reaction (nh) versus ground horizontal displacement (yo), when a constant pile flexural rigidity with concrete cracking was taken into account. Average value of (nh) was determined by these curves for yo, ranging from 6 to 12 mm (natural soil) or 12 to 18 mm (wetted soil)