Integrating MWD and CPT Data for Rigid Inclusion Performance Verification-PPT Presentation

PPT Presentation

Pdf Summary

The presentation describes using measurement-while-drilling (MWD) and cone penetration test (CPT) data to assess the performance of rigid inclusions (RIs). Typically installed with displacement augercast pile systems, RIs improve soft ground by transferring loads through a load-transfer platform. They are generally not treated as deep foundations; settlement, rather than bearing capacity, often governs design.<br /><br />MWD installation logs capture parameters that can be reviewed during construction and compared with test elements. These data can be used to calculate a penetration resistance index (PRI) and an integrated resistance index (IRI), the latter obtained by summing PRI below the element’s neutral plane. The indices can help estimate axial resistance and assess production elements. CPT trends and interpreted strain-gauge measurements provided independent comparisons in the case study.<br /><br />For a seven-story residential project, a successful test element had an IRI of 495 kips and resisted 580 kips below the neutral plane, giving a factor of about 1.17. Applying this factor to the lowest production-element IRI of 370 kips yielded an estimated resistance of 433 kips, above the 381-kip design requirement.<br /><br />The authors conclude that each RI acts as an exploration probe and that installation data can support efficient performance verification. Predicting axial resistance from installation parameters shows promise, though the approach relies on comparison with test elements and project-specific data.

Keywords

measurement-while-drilling

MWD

cone penetration test

CPT

rigid inclusions

settlement

load-transfer platform

penetration resistance index

integrated resistance index

axial resistance