An Extension of the Mobility Analysis of the Impulse Response Method for Coupled Pile-soil Integrity Testing

Abstract

ABSTRACT Among commonly used nondestructive testing techniques for evaluating the integrity of pile foundations, reflection methods based on stress wave propagation are widely accepted as cost-effective tools. For uncapped piles, the frequently used Impulse Response (IR) method has long been recognized as one of the most reliable methods. This paper extends prior developments on the IR method’s core mobility analysis by accounting not only for the pile, but also for the coupled pile-soil system through the introduction of suitable soil parameters. New expressions are derived encompassing the pile’s and soil’s stiffness and damping; the expressions are validated via numerical experiments over a wide range of stiffness and damping data. With the aid of the new mobility formulas, it would be possible to allow not only for the non-destructive assessment of the pile, but also for the recovery of the surrounding soil’s dynamic characteristics. Thus, the dynamic properties of the soil extracted from in-situ tests are referable data which can be potentially useful for the simulation of soil-structure-interaction effects in various types of dynamic problems related to soil dynamics and earthquake engineering.