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Title:

BRIDGE FROST OCCURRENCE AND PREDICTION
Cover of BRIDGE FROST OCCURRENCE AND PREDICTION

Accession Number:

00974859

Record Type:

Component

Availability:

N/A
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Order URL: http://worldcat.org/issn/00978515

Abstract:

Frost on bridges can present hazardous conditions to motorists, particularly if it occurs when adjacent roadways are clear of frost. Minimizing materials cost, vehicle corrosion, and negative environmental impacts calls for strategic use of frost-suppression chemicals. Accurate forecasts of bridge frost onset times, frost intensity, and frost disappearance (e.g., melting or sublimation) are needed to help roadway maintenance personnel decide when, where, and how much frost-suppression chemical to use. The authors have developed a finite-difference algorithm (BridgeT) that simulates vertical heat transfer in a bridge based on evolving meteorological conditions at its top and bottom as supplied by a weather forecast model. This algorithm simulates bridge deck surface temperature at 1-min intervals and calculates volume per unit area (i.e., depth) of frost deposited, melted, or sublimed. From this are produced forecasts of frost onset time, frost "depth," and duration of frost on the bridge. Evaluation of forecast methods for predicting frost on bridges and roadways is difficult because of a lack of observations of frost occurrences. Early morning observations of untreated bridges near Ames, Iowa, were made during two winter seasons to establish a database of bridge frost occurrences and non-occurrences. When frost was detected, observations were continued until the frost disappeared and thereby provided additional information on duration and timing of onset and demise of frost. Bridge frost predictions as well as predictions of air temperature, dew-point temperature, bridge-top surface temperature, and wind speed, are compared with observed and measured values to assess skill in forecasting bridge frost and associated conditions. Lack of agreement between forecasts of frost characteristics and visual observations on a particular (presumed chemical-free) bridge may arise from (1) inaccuracies in forecasts of meteorological variables by the weather forecast model at its model resolution, (2) spatial variability in meteorological conditions below resolution of the forecast model, (3) inaccuracies in simulation of heat transfer by BridgeT, or (4) an inability to detect frost visually.

Supplemental Notes:

Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

Report/Paper Numbers:

E-C063,
SNOW04-005
SNOW04-039

Language:

English

Corporate Authors:

Transportation Research Board

500 Fifth Street, NW
Washington, DC 20001 United States

Authors:

Greenfield, T M
Takle, E S
Tentinger, B J
Alamo, J J
Burkheimer, D
McCauley, D

Pagination:

p. 391-398

Publication Date:

2004-6

Serial:

Transportation Research Circular

Issue Number: E-C063
Publisher: Transportation Research Board
ISSN: 0097-8515

Conference:

Sixth International Symposium on Snow Removal and Ice Control Technology

Location: Spokane, Washington
Date: 2004-6-7 to 2004-6-9
Sponsors: Transportation Research Board; Washington State Department of Transportation; American Association of State Highway and Transportation Officials; and Federal Highway Administration.

Features:

Figures (2) ; References (4) ; Tables (3)

Subject Areas:

Bridges and other structures; Highways; Maintenance and Preservation; I62: Winter Maintenance

Files:

TRIS, TRB

Created Date:

Jun 10 2004 12:00AM