Non-destructive Testing of Piles: An Experimental Study

The construction of Deep Foundations has been in practice in India for several years and state of art design and construction techniques are being followed by practicing engineers for design of reinforced concrete and steel piles—both driven and bored. However, the quality control check of these underground structures is still in development stages and several destructive, partially destructive, and non-destructive tests are in various stages of developed and experiment. This paper presents an experimental study to determine the quality of piles based on non-destructive methods—low-strain pulse echo method and cross-hole sonic logging method. These two methods have recently gained wide acceptance as quality control procedure for piles in India being not only cost effective, but also provide reliable near accurate results if analyzed properly. To study the quality of piles, two bored reinforced concrete piles have been cast at proximate location using same construction techniques; one without any defect and one with known defects at known locations; and an attempt has been made to find the known defect with use of non-destructive tests. The paper discusses findings of two testing methods (low-strain pulse echo and cross-hole sonic logging) in detail and presents the effectiveness, analyzing techniques, and limitations of both the methods.