Comparing Measurement While Drilling (MWD) to Cone Penetration Test (CPT) data and implications for deep foundation design-PPT Presentation

PPT Presentation

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The study evaluates whether Measurement While Drilling (MWD) data can complement Cone Penetration Test (CPT) data in deep foundation design. Researchers instrumented the Nebraska DOT Geoprobe 3230DT drill rig to record drilling advancement speed, rotation speed, feed pressure, and torque pressure. They processed and normalized the MWD measurements before comparing them with CPT results.<br /><br />For hollow-stem auger drilling, the team used drilling parameters to calculate specific energy and examined its relationship with undrained soil shear strength. They then estimated the unit side resistance and toe bearing of drilled-shaft layers using MWD-derived strength estimates, and compared those estimates with values calculated using CPT and laboratory-based methods.<br /><br />The normalized MWD and CPT data showed similar trends, suggesting that MWD measurements may help characterize subsurface conditions. However, preprocessing is important, and the observed correlation between specific energy and undrained shear strength was weak—possibly because drilling operations were not optimal. Although the dataset was limited, results indicate potential for using MWD data to estimate soil strength and foundation resistance. Further data collection and validation are needed before the approach can be relied upon for design.

Keywords

Measurement While Drilling

Cone Penetration Test

deep foundation design

specific energy

undrained shear strength

soil strength estimation

drilled shaft resistance

subsurface characterization

hollow-stem auger drilling

geotechnical data