Instrumented elastomeric bridge bearings

Co-author's name from technical rept. documentation page.; "June 2000."; Includes bibliographical references (leaves 137-142).; Final report.; Prepared in cooperation with Ohio Department of Transportation and U.S. Department of Transportation, Federal Highway Administration under state job no.; Harvested from the web on 3/8/06This report presents the results of tests and analyses performed on elastomeric bridge bearings. The focus of this research was the measurement of bearing deformations in the field and assessment of the feasibility of using instrumented elastomeric bearings to monitor bridge condition. The bearing deformations were successful measured in the field during the deck concrete pour and a static truck test. Shear, compression, rotation, and fatigue tests have been carried out in the laboratory and at the manufacturer's facility. Full scale bearings (shape factor 11) were tested at the manufacturer and installed in the field. Model bearings (shape factor 11 and one-quarter the plan area of the full scale bearings) were tested at the manufacturer and in the laboratory. Test bearings (shape factors 5,7, and 10) were tested in the laboratory. The bearing material was 50 Durometer neoprene. The analyses support the testing and considered the bridge-bearing system. The stiffnesses of the bearings are explicitly included in the analyses. A singular characteristic of this experimental research is the focus on the in-service behavior of the bearings.This report presents the results of tests and analyses performed on elastomeric bridge bearings. The focus of this research was the measurement of bearing deformations in the field and assessment of the feasibility of using instrumented elastomeric bearings to monitor bridge condition. The bearing deformations were successful measured in the field during the deck concrete pour and a static truck test. Shear, compression, rotation, and fatigue tests have been carried out in the laboratory and at the manufacturer's facility. Full scale bearings (shape factor 11) were tested at the manufacturer and installed in the field. Model bearings (shape factor 11 and one-quarter the plan area of the full scale bearings) were tested at the manufacturer and in the laboratory. Test bearings (shape factors 5,7, and 10) were tested in the laboratory. The bearing material was 50 Durometer neoprene. The analyses support the testing and considered the bridge-bearing system. The stiffnesses of the bearings are explicitly included in the analyses. A singular characteristic of this experimental research is the focus on the in-service behavior of the bearings

Other title: Veteran's Glass City Skyway Bridge monitoring system

"February 2017."; "FHWA/OH-2014-7"--Technical Report Documentation Page.; Includes bibliographical references.; Final report.; Sponsoring agency: Ohio Department of Transportation; State Job Number 135032; ODOT Agreement No. 26711The Veterans' Glass City Skyway Bridge is a large cable stayed bridge in Toledo, Ohio owned and operated by the Ohio Department of Transportation. The bridge superstructure and, particularly, the stay cables have been subject to periodic icing events. An icing event monitoring system was designed and installed on the bridge to enable the bridge operators to mitigate the potential hazards associated with ice falling onto the bridge deck from the stays. The monitoring system collects regional weather data and integrates it with data from a weather station on the bridge and icing sensors mounted on the stays. The monitoring system displays information on ice accumulation and potential shedding for the operators on a compact dashboard. This user manual was provided to ODOT when the monitoring system was transitioned to ODOT from the universities conducting the research, testing in the laboratory and field, and development after a trial operation period covering two winters. It contains operation and maintenance instructions for the hardware and software that constitute the monitoring system

Other title: Assessment of the load rating of bridges with a load rating factor greater than 1.35 to meet specialized hauling vehicle requirements; Other title: At head of title: Structures research on call services; Other title: Title from technical report documentation page: Structures research on-call services: task 1 - assessment of the load rating of bridges with RF ≥ 1.35 to meet special hauling vehicle requirements

"January 2019."; "Prepared in cooperation with the Ohio Department of Transportation (ODOT) and the U.S. Department of Transportation, Federal Highway Administration"--Technical report documentation page; Includes bibliographical references (page 35); Final report September 2015-August 2017; Sponsored by Ohio Department of Transportation, Office of Statewide Planning & Research; State job number: 135250Final report (64 pages)The statistical study considered real bridges in Ohio with a rating factor (RF) ≥ 1.35 whose section properties may vary along the length of the bridge. A sample of these bridge was examined. The sample included a minimum of thirty bridges of the each of the six common types studied. No actual bridge was found to have an SHV RF < 1.00. To extend the study the ratio of the Ohio legal RF to the SHV RF was calculated for all bridges in the sample. Three simple span bridges whose spans were from 70 - 80 ft. had a ratio greater than 1.35. The maximum ratio was 1.37. Because the sample size of a statistical study is limited, a parametric study of single and multi-span bridges was conducted. The parametric study considers live load effects on a hypothetical bridge with uniform stiffness and addresses all practical spans for simple span bridges and all practical ratios on interior to exterior spans for multi-span bridges. The maximum span length considered for simple and multi-span bridges was 200 ft. For simple span bridges, the highest ratio of RFs was 1.36 for an 80 ft. span. For multi-span bridges, the highest ratio of RFs for positive moment and negative moment was 1.35 and 1.37, respectively. Shear did not govern in the parametric study for any bridges. The consistency of the statistical and parametric studies shows the general applicable of the parametric model

Other title: Long Term Maintenance of the Anthony Wayne Suspension Bridge Main Cables

"Prepared in cooperation with the Ohio Department of Transportation and the U.S. Department of Transportation, Federal Highway Administration."; "January 2017."; Includes bibliographical references (pages 57-59).; Final report.; Sponsoring Agency: Ohio Department of Transportation; State Job No.: 135111The Anthony Wayne Bridge, Ohio's only suspension bridge, is undergoing an extensive rehabilitation. Prior to taking action to preserve the cables, ODOT must decide what measures to take to evaluate the condition of the cables, how best to rehabilitate the cables to slow their aging and how to monitor the degradation in the cables' strength as they age. The three goals of this study are: 1. Determine the current condition of the main cables; 2. Determine a rehabilitation technology to most efficiently and economically slow their aging; 3. Select a long term monitoring strategy that accurately tracks the changes the condition of the cables over time. This research should help ODOT make decisions for preserving the cables

Ice prevention or removal on the Veteran's Glass City Skyway cables

Title from page 3.; "August 2014."; Executive summary report (7 leaves) laid in.; Includes bibliographical references (leaves 289-305).; Final report.; Prepared for the Ohio Department of Transportation, Office of Statewide Planning & Research; State Job Number 134489; Harvested from the web on 10/28/14The Veteran's Glass City Skyway is a cable-stayed bridge in Toledo, Ohio owned by the Ohio DOT. Five times in the seven winters the VGCS has been in service, ice has formed on the stay cables. Ice up to 3/4" thick and conforming to the cylindrical shape of the stay has formed. As the stays warm, ice sheds in curved sheets that fall and can be blown across the bridge. The falling ice sheets pose a potential hazard and may require lane or bridge closure. Because of the specialized knowledge required, this problem required a team including experts in icing, the VGCS construction, the structural measurement system on the bridge, and green technology. The VGCS stay sheaths are made of stainless steel, have a brushed finish, lack the usual helical spiral and have a large diameter. No existing ice anti/deicing technology was found to be practical. Therefore, ODOT elected to manage icing administratively. A real-time ice monitoring system for local weather conditions on the VGCS and the stays was designed. The system collects data from sensors on the bridge and in the region. The study of the past weather and icing events lead to quantitative guidelines about when icing accretion and shedding were likely. The monitoring system tracked the icing conditions on the bridge with a straightforward interface so information on the icing of the bridge is available to the bridge operators. If the conditions favorable to icing occurred, the monitoring system notified the research team and appropriate ODOT officials. If ice has formed, the monitor tracks the conditions that might lead to ice fall

Other title: Overhead sign failure investigation; Other title: At head of title: Structures research services 2018-2021; Other title: Title from technical report documentation page: Division of Engineering Research on Call, Task #1 - overhead sign failure

Revision 1.; "May 2019."; Includes biblographical references (page 18).; Final report; Sponsored by Ohio Department of Transportation, Office of Statewide Planning & Research; State job number: 135785Final report (18 pages

Evaluation of stay-in-place metal forms

"May 2006."; Includes bibliographical references.; Final report.; Performed by University of Toledo, Dept. of Civil Engineering in cooperation with Ohio Dept. of Transportation and U.S. Dept. of Transportation, Federal Highway Administration under state job no.; Harvested from the web on 9/20/06An experimental study was conducted to determine if the use of stay-in-place metal forms (SIPMF) resulted in reduced bridge deck concrete quality over the life of the bridge compared to bridge decks formed conventionally without SIPMF. A corollary problem addressed was to determine the potential for using ground penetrating radar (GPR) to inspect the bridge deck concrete quality immediately above the SIPMF. Experimental studies were carried out on three Northern Ohio bridges that were partially constructed approximately 40 years ago using SIPMF. All these bridges had regions where there was no SIPMF. Cores were extracted from these bridges. The deck concrete quality in regions with SIPMF was compared to the concrete quality in regions without SIPMF. Visual inspections and compression, chloride, permeability and ultrasound tests were performed. Ultrasound is is a very discriminating technique to use for comparison. Analysis of the inspection and test data showed no significant difference between the concrete quality in regions with and without SIPMF. This is consistent with the literature. An experimental study was carried out that compared the predicted concrete quality from a GPR survey to the concrete quality measured by testing verification cores. A GPR signal attenuation map was developed to predict the quality of the concrete in the bridge. This attenuation map was used to select the locations of the verification (ground truth) cores to be harvested. Visual inspections and compression and ultrasound tests were carried out on the ground truth cores. Ultrasound, when coupled with compression testing, is a well established technique to assess concrete condition. Analyses of the inspections and test data showed that GPR was not effective in predicting concrete quality between the bottom layer of rebar and the top of the SIPMF. The implementation potential for SIPMF in Ohio was considered. Nothing in the present research indicates that implementation of SIMPF in Ohio will be less successful than in the neighboring northern states. Reaping the full benefits will require some time as Ohio contractors and bridge inspectors become familiar with SIMPF. Important aspects of implementation are inspection, materials, repair and specifications.An experimental study was conducted to determine if the use of stay-in-place metal forms (SIPMF) resulted in reduced bridge deck concrete quality over the life of the bridge compared to bridge decks formed conventionally without SIPMF. A corollary problem addressed was to determine the potential for using ground penetrating radar (GPR) to inspect the bridge deck concrete quality immediately above the SIPMF. Experimental studies were carried out on three Northern Ohio bridges that were partially constructed approximately 40 years ago using SIPMF. All these bridges had regions where there was no SIPMF. Cores were extracted from these bridges. The deck concrete quality in regions with SIPMF was compared to the concrete quality in regions without SIPMF. Visual inspections and compression, chloride, permeability and ultrasound tests were performed. Ultrasound is is a very discriminating technique to use for comparison. Analysis of the inspection and test data showed no significant difference between the concrete quality in regions with and without SIPMF. This is consistent with the literature. An experimental study was carried out that compared the predicted concrete quality from a GPR survey to the concrete quality measured by testing verification cores. A GPR signal attenuation map was developed to predict the quality of the concrete in the bridge. This attenuation map was used to select the locations of the verification (ground truth) cores to be harvested. Visual inspections and compression and ultrasound tests were carried out on the ground truth cores. Ultrasound, when coupled with compression testing, is a well established technique to assess concrete condition. Analyses of the inspections and test data showed that GPR was not effective in predicting concrete quality between the bottom layer of rebar and the top of the SIPMF. The implementation potential for SIPMF in Ohio was considered. Nothing in the present research indicates that implementation of SIMPF in Ohio will be less successful than in the neighboring northern states. Reaping the full benefits will require some time as Ohio contractors and bridge inspectors become familiar with SIMPF. Important aspects of implementation are inspection, materials, repair and specifications

Experimental and Theoretical Studies of Wet Snow Accumulation on Inclined Cylindrical Surfaces

Wet snow accumulation on bridge cables and its shedding due to external phenomena such as rise in temperature, wind, and gravity is a serious threat to the safety of cars and pedestrians crossing the bridge. Commonly the accumulated snow on bridge cables is removed by external means such as mechanical removal or heat treatment which are expensive, time-consuming, and high-risk processes and are conducted based on little or no information available regarding the actual size and shape of the accumulated snow. In addition, cleaning of cables using the mechanical methods can potentially lead to erosion of cable materials when applied over years, resulting in enhanced surface roughness and potentially increased wet snow/ice accumulation during future precipitation events, and sometimes might require replacement of cable stays, which is an extremely costly and complicated task. Optimizing the number of mechanical cleaning procedures such as chain release through predicting the shape and thickness of the accumulated snow on the cable stays reduces the cost, time, and risk associated with the process. In this study, wet snow accumulation on torsionally rigid inclined cylinders of high-density polyethylene (HDPE) has been studied experimentally and numerically. A 2-D numerical model has been developed utilizing weather data to predict the thickness and the shape of the accumulated wet snow on inclined cylindrical surfaces. Outdoor experiments were also conducted to measure the density and thickness of accumulated snow, while monitoring the weather data real time. Overall, snow density was found to be linearly increasing with an increase in wind velocity, during snow precipitation. The maximum thickness and shape of the accumulated snow on cables obtained from the numerical model were found to be in good agreement with the outdoor experimental data. This work aims to provide a mean for prediction of snow accumulation on surfaces for optimizing the efficiency of the costly and high-risk snow removal procedures