Integrity Testing of Drilled Shafts – Existing and New Techniques

Document Info

Title: Integrity Testing of Drilled Shafts – Existing and New Techniques

Authored By: Naresh C. Samtani, PE, PhD, Frank Jalinoos, Dennis M. Poland, RG

Abstract

The use of drilled shafts as a cost-effective deep foundation system has grown tremendously in the last couple of decades. With the advent of non-redundant large diameter single shaft foundation systems it has become critical to ensure that the constructed product meets the design requirements. Non-destructive tests (NDT) are commonly used to evaluate the structural integrity of the constructed drilled shafts.The two most common NDTs are performed using the Cross-hole Sonic Logging (CSL) and the Gamma-Gamma Density Logging (GDL) methods. In addition to discussing these common NDT methods, this paper presents their newer variations and how they are used to identify anomalies.A roadmap is presented to progress from the identification of anomalies to the verification and imaging of defects and finally to methods for remediation of defective shafts.