Majid Jazebi - Master Student Geotechnical Engineering group, Sharif University of Technology
Mohammad Mehdi Ahmadi - Professor, Geotechnical Engineering group, Sharif University of Technology

Drilled shafts (Bored piles) are one of the most extensively used pile foundations in both sandy and clayey soils. The tip resistance of a drilled shaft is an important part of its axial bearing capacity. Determination of plastic zone around the tip of drilled shaft can help to study the end bearing capacity of this type of deep foundation. There are few studies carried out to investigate the size of plastic zones for both driven and drilled piles. This study includes a numerical modeling procedure to determine the size of plastic zones in drilled shafts. The results obtained in this study show that the soil parameters such as friction angle and elastic modulus have a direct effect on the size of plastic zones. Also, an increase in pile diameter results in bigger plastic zones. However, an increase in pile length results in smaller plastic zones. Furthermore, some typical ranges of the dimensions of plastic zones for different states of sand are provided.

Drilled shaft, Sand, Flac 2D, Plastic zone, Bored pile