1. ASTM D1143, Standard Test Method for Piles under Static Axial Compressive Load, New York, pp. 87-97, (1994).
2. ASTM D5434, Standard Guide for Field Logging of Subsurface Explorations of Soil and Rock1, New York, pp.1-3, (1997).
3. Das B.M., Principles of foundation engineering”, 6th Edition, International Student Edition, United States, (2007).