Engineering and Technology Journal

In this paper investigation in the end bearing and shaft resistance of bored piles embedded in medium sand and subjected to axial load for wide rang of stress levels starting from laboratory dimensions and go toward field dimensions were made by utilizing the finite element method. The soil is modeled using hyperbolic soil model with empirical equation account for reduction of angle of internal friction Ø with increase in stress level while the bored pile assumed as a linear elastic material. It was found that the stress level has a significant effect on pile’s behavior and the small scale model in laboratory dimension not represent the real behavior of pile in field dimensions and if the results from such dimensions are adopted, it will lead to overestimate of bearing capacity factor Nq. Also, the effect of embedment ratio (L/D) on pile’s behavior is examined in this study and the results showed that the embedment ratio (L/D) increases the bearing capacity factor Nq up to a certain length beyond it the effect of embedment ratio (L/D) diminished.

This study describes a three-dimensional nonlinear finite element model suitable for the analysis of high strength reinforced concrete arched beams under static load. The twenty node isoperimetric brick element has been used to model the concrete and reinforcing steel bars have been idealized as axial members embedded within the brick elements. Perfect bond was assumed to occur between the concrete and the reinforcing bars. The behavior of concrete in compression is simulated by an elasto-plastic work hardening model followed by a perfectly plastic response, which is terminated at the onset of the crushing. In tension, a smeared crack model with fixed orthogonal cracks has been used. High and normal strength reinforced concrete arched beams have been analyzed in the present study. Parametric studies have been carried out to investigate the effect of radius to span length ratio, boundary conditions, (α2) [the sudden loss of stress at the instant of cracking], and effect of compressive strength. In general good agreement between the finite element solutions and the experimental results have been obtained.