**5. Conclusions**

Strain gages are critically important instruments for monitoring the performance of a deep foundation element undergoing a load test. Strain gage data must be properly analyzed in order to gain insight into the true soil-structure interaction. In order to verify design assumptions and particularly to optimize computer models, the unit capacity curves (so-called t-z and q-z curves) must be obtained from the load test. Properly analyzed strain gage data contributes to both components of these curves. However, strain gages are not load cells – the conversion of strain to load is not as straightforward as linear elastic theory may lead one to believe. Careful attention must be given to the selection, placement, monitoring and interpretation of strain gages in deep foundation load testing. The techniques described herein have been developed and successfully deployed by the author and others for over two decades to utilize strain gages in deep foundation load testing.
