Constructing deep foundations is both an art and a science and their as-built acceptance should be based on evidence of quality confirmed by testing. Early prevention of problems is the most effective means to avoid costly and time consuming construction delays. Recent developments in equipment and methods aid in real-time monitoring of various pile installations. For driven piles, monitoring of diesel hammers has been done for years using the Saximeter. The measured kinetic energy of any hammer type can now be transmitted by telemetry to the Saximeter unit and stored electronically in an installation log for downloading or computer printout. Traditionally, the Pile Driving Analyzer (PDA) is used by an experienced engineer who collects and interprets measurements on the construction site, and later issues a report after returning to the office. The engineer's travel and availability often dictates the testing schedule and impacts the construction activity. Utilizing wireless cell phones, dynamic pile testing can now be done remotely at the contractor's convenience with substantial cost savings and even more substantial time savings. In the office, the PDA engineer receives and simultaneously views the measured data in real-time, immediately analyzes the data, and summarizes the monitoring results, often issuing the test report within hours of the test. Thus, the foundation installation and quality assurance testing proceed without interruption or delay. Devices are available for auger cast-in-place pile installations to guide the contractor in real-time to installing a good pile with documented quality so that it can be accepted without doubts or time delays. For drilled shafts, the most common quality assurance tool is cross hole sonic logging (CSL). New 3D tomography analysis of CSL data holds further promise to evaluate the quality of drilled shafts.

Quality of cast-in-place foundation applications, including Augered-Cast-in-Place (ACIP) piles and Drilled Shafts (particularly those cast under slurry) is greatly dependent upon the practices of the site personnel. Due to the installation techniques used to install these elements, it is usually not possible to inspect the hole through any Non-Destructive Test (NDT) method prior to grout or concrete placement, but there are several NDT methods available to indirectly assess the integrity of these completed elements. This paper will compare several NDT methods with the method of Thermal Integrity Profiling (TIP) for confirming integrity in ACIP piles and drilled shafts. The TIP method evaluates the integrity over 100% of the element cross section by measuring the hydration temperature during the early curing of the grout/concrete along the length of the element. The temperature measurements are typically concluded within 4 to 48 hours after placement, thus accelerating construction. For the generally small diameter ACIP piles, meaningful measurements often can be at as little as 4 to 8 hours after casting. The use of TIP in ACIP piles and Drilled Shafts can effectively overcome several limitations inherent in other NDT methods. Thermal Integrity Profiling will be described and several examples will be presented where TIP testing was used to confirm the structural integrity of ACIP piles and Drilled Shafts.

Augercast piles have become increasingly common. Engineers are attracted to this pile type as a way to reduce foundation costs. In addition, the applied design loads have increased as the equipment used by the augercast contractors has increased to both larger diameters and longer lengths, allowing augercast piles to be considered on a wider range of project sites. The performance of this pile type requires a shaft with good integrity and sufficient soil resistance. However, inspection for this pile type is difficult. The augercast pile is constructed in situ and at no time during the process can the "hole" or injected concrete along the shaft be inspected visually. By contrast, driven piles can be inspected prior to installation. Closed end steel pipes can be visually inspected after driving and prior to concreting. The integrity of driven piles is further indirectly confirmed by driving the pile to the required blow count, and in many cases dynamic pile testing is used to confirm whether or not a pile has suffered damage, even for solid section piles like H piles or square concrete piles. While pile and shaft performance can be verified by static load tests, the cost and time constraints prevent static testing for all but a few augercast piles on even the largest site. For augercast piles, current typical practice with visual inspection does inspect the pile completion process including installation of reinforcement. However, typical inspection during the critical augercast grouting phase in the United States is often limited to counting the total number of pump strokes (and computing a total volume based on that count). This paper describes automated electronic monitoring during construction to assure proper incremental grout volume versus depth for every augercast pile on site. Dynamic integrity inspection after installation and dynamic pile capacity determination for larger percentages of augercast piles on site are discussed. These alternate inspection methods increase the confidence in augercast pile foundations.

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