CURVATURE AND BENDING MOMENTS FROM INCLINOMETER DATA

Bending moments in excavation support walls and deep foundations are often estimated using curvature derived from inclinometer surveys. The basic idea involves fitting a curve or a series of curves to the inclinometer data. The curvature is then estimated as the second difference of the displacement profile. Although many methods are available to estimate curvature, there is a lack of a consistent standard in deducing curvature from inclinometer readings. 12 methods for estimating curvature that lend themselves well to spreadsheet or programmable calculations are reviewed and are then applied to 60 sets of inclinometer readings obtained from a variety of walls and drilled shafts. Included are 6 laterally load tested drilled shafts monitored using both inclinometers and strain gauges. A direct comparison of curvatures from inclinometers with those from strain gauges was performed. The comparisons show that a piecewise cubic polynomial curve fitting a moving window of 5 successive inclinometer data points provides curvature values that are in good agreement with those from strain gauges, and is proposed as a reasonable method for estimating bending moments from inclinometer data.

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  • English

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  • Accession Number: 00961748
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 27 2003 12:00AM