<p><p><strong>References:<br></strong><em>Bruce (1997b)<br>Bruce and Juran (1997)<br>DFI-ADSC (2002)<br>Gibler et al. (2005)<br>Gomez et al. (2008a, 2008b)<br>Sabatini et al. (2005)</em></p><p><strong>Method Summary</strong></p><p>Proof testing is conducted during construction on a percentage of installed production micropiles, which are intended to be incorporated into the structure if the test load does not cause failure. Proof tests provide verification of a consistent construction process, design adequacy, and material quality. The micropiles are individually tested using a static load which is applied in compression, tension, or laterally. The load is applied in increments until the specified maximum test load. Proof tests use a maximum test load which typically corresponds to at least 150% of the design load. Acceptance criteria are defined by a specified acceptable pile head movement at the design load and total pile head movement under a sustained load (i.e. creep). If failure occurs during proof load testing, the design and/or the construction procedure must be adjusted to address the exposed deficiencies. The results from proof tests can be used to determine the bond strength of the micropile. Additionally, equations can be used to determine the micropile effective bond length and the free length. Typical load testing equipment includes: a hydraulic jack and pump; reaction and reference beams; pressure gauges and load cells; dial gauges; and a wire with mirror and scale (Sabatini et al. 2005). A creep test is performed as part of the proof test.</p><p><strong>Accuracy and Precision</strong></p><p>Proof testing accurately and precisely assesses the construction quality of micropile installation.</p><p><strong>Adequacy of Coverage</strong></p><p>Proof tests are considered to provide a high amount of coverage. In general, it is recommended to test at least 5% of the production micropiles. Depending on the site and project conditions, more or less tests are required. Table 7-3 in Sabatini et al. (2005) recommends a minimum number of test micropiles for proof testing.</p><p><strong>Implementation Requirements </strong></p><p>The requirements of proof testing are not excessive. Proof testing is typically required as a quality assurance procedure for micropile projects.</p><p><strong>General Comments</strong></p><p>Proof tests are performed as part of verifying consistent construction procedures throughout the project and the micropile strength meets the required minimum design load. These results are then used to determine the ability of the micropiles to carry an expected service load.</p></p>