Qualitative Interpretation of Load-Settlement Curves of Bored Piles

Static load testing of piles yield only the load-settlement behaviour of piles. While it is useful to get the load-settlement behaviour, the static load testing yields no other direct information regarding the distribution of load carrying capacity along the pile shaft and at the pile toe. However, various researchers have shown that the shape of the load-settlement curve can be interpreted to get such information. This paper attempts to discuss the reasons for commonly observed variations of the shape of the load-settlement curves obtained by testing bored piles and the use of the Elastic Shortening Line (ESL) in interpretation of the load-settlement curves. Load-settlement curves are categorized using the ESL and a mathematical model, developed to simulate the load-settlement behaviour of piles, is used to investigate the reasons for variation of the shape of the load-settlement curves of different categories. Accuracy of the commonly used Van Weele [8] method to estimate the skin friction from the load settlement curve is also discussed.