Drilled shafts and other mixed or cast-in-place concrete deep foundation elements can be costly solutions. These foundations usually carry very high design loads, and often serve as a nonredundant, single load-carrying unit. These conditions have created a need for a high-level of quality assurance and control applied to each in-place constructed deep foundation element. The non-destructive testing method, Cross-Hole Sonic Logging (CSL), currently offers the most reliable technique for assessing the integrity of in-place constructed deep foundation elements. Recent years have seen progress in CSL instrumentation, taking advantage of the available computer technology. The software applications, however, have greatly fallen behind, thereby limiting the effectiveness and potential of the CSL method and deep foundations integrity testing in general. A new, original CSL testing system by the name of PISA (Pile Integrity Sonic Analyzer) makes use of an innovative software and data acquisition system, hence representing the state-of-theart in deep foundation integrity testing. The PISA has the capability to show real-time graphical information during logging, including planar tomography, which can identify the boundaries of a compromised zone within the foundation element. The equipment operates completely in a Windows TM graphical environment allowing alphanumeric and graphical reports to be generated directly into word processing software. The real-time graphical representation during logging and the ease of reporting enables immediate, extensive on-site evaluation and decision making.

The performance of drilled shafts is known to be controlled by the type and quality of the construction methods. A comparison between different methods or different contractors is typically not available under the prevailing bidding and testing procedures. Six drilled shafts 0.70 m in diameter and 25.0 m long were installed and tested to structural failure at a site in Haifa, Israel. Three of the shafts were constructed using the Continuous Flight Auger (CFA) construction method and three of the drilled shafts were constructed using bentonite slurry. Site and shafts details are provided. The drop weight testing system is reviewed. Test results comparing the load carrying capacity of the shafts, load distribution and structural outlines are presented and discussed. While the bentonite slurry construction resulted in a more uniform constructed foundation capable of carrying higher load, the explanation to the variation at the given site conditions may be a result of the contractor's quality rather than advantages of one technology over another.

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