MECHANICAL STRAIN RECORDER ON A CONNECTICUT BRIDGE

In a three-phase, one-year (April 1973 to April 1974) program, the traffic landing on span No. 10 in the Yellow Mill Pond Viaduct on Interstate 95 in Bridgeport, Connecticut, was monitored by mechanical strain recorders (MSR'S) in conjunction with an electrical recording system including electrical strain gages (ESG'S) and an oscillograph recorder. Since previous demonstrations had indicated the promise of the MSR as an economical, accurate means of recording actual bridge load spectra, the program objective was primarily to investigate the accuracy, gage length, recording capacity, and repeatability of the MSR and the long-term environmental and usage effects on the MSR. Also intended was the monitoring of truck crossings and the subsequent correlation of the truck survey data with the recorded MSR and ESG data. The major results of this investigation were as follows: (1) the MSR proved accurate accurate since its strain data could be used to accurately predict the simultaneously recorded ESG strain data, (2) the desired gage length is a function of the frequency and magnitude of the recorded MSR cycles and therefore varies with the loadings peculiar to each bridge, (3) the minimum recording capacity was two weeks, (4) the characteristics of MSR strain range exceedance curves were repeated throughtout a 10-month recording period, (5) the MSR functioned in all salt-water weather conditions with the use of a protective cover, and (6) the lack of correlation between the truck survey data and the MSR and ESG data indicated that truck survey data alone would not suffice for determining the strain load spectrum of a bridge and consequently that the spectrum should be found empirically by an economic and accurate recorder such as the MSR.

  • Supplemental Notes:
    • Prepared in cooperation with FHWA and Connecticut DOT.
  • Corporate Authors:

    Technology, Incorporated

    Instruments & Controls Division, P.O. Box 3036, Overlook Br
    San Antonio, TX  United States  78217
  • Authors:
    • Dickey, R L
    • Severyn, T P
  • Publication Date: 1974-12

Media Info

  • Pagination: 111 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00098427
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Report/Paper Numbers: FCP 45G1-222 Final Rpt.
  • Files: TRIS, USDOT
  • Created Date: Oct 18 1975 12:00AM