Comprehensive Calibration Strategy for Texas Department of Transportation Falling Weight Deflectometer Fleet;Research rept. (Interim) Jul 01-Jul 02

摘要

The degree of accuracy with which the Falling Weight Deflectometer (FWD) data are collected and analyzed has a direct impact on the conclusions drawn in many aspects of TxDOT operation. TxDOT owns 15 FWD units, one of the largest FWD fleets of any single transportation agency in the world. Both good repeatability and reproducibility are considered to be of major importance for an adequate interchangeability of the FWD fleet. As summarized in Research Report 1784-1, the existing calibration protocol improves the repeatability of each FWD but it does not address the reproducibility of the fleet. In this report a new calibration process has been recommended that seems to improve the reproducibility of the fleet. The calibration process consists of three steps: a routine and diagnostic maintenance, and a simple calibration procedure followed by a comprehensive one if necessary.