Field Evaluation of Steel Girder Bridge

1997 ◽  
Vol 1594 (1) ◽  
pp. 140-146 ◽  
Author(s):  
Vijay K. Saraf ◽  
Andrzej S. Nowak

The objective of the study was to verify the load-carrying capacity of an existing steel girder bridge. The selected structure was a 70-year-old deteriorated bridge in Michigan. The load-carrying capacity of the bridge was in question because of extensive corrosion of the steel girders. An initial rating indicated that the bridge had a marginal operating rating factor for 11-axle two-unit trucks, which are the heaviest vehicles allowed in Michigan. To avoid the load limit posting, it was decided that investigators would verify by nondestructive testing whether the bridge is safe to carry normal truck traffic. The test procedures used on the selected bridge included tests for obtaining stress histogram measurements and weigh-in-motion measurements and a proof load test. The methodology and the results are described.

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Rajinder Ghai ◽  
Prem Pal Bansal ◽  
Maneek Kumar

There is a common phenomenon of shear failure in RCC beams, especially in old buildings and bridges. Any possible strengthening of such beams is needed to be explored that could strengthen and make them fit for serviceable conditions. The present research has been made to determine the performance of predamaged beams strengthened with three-layered wire mesh polymer-modified ferrocement (PMF) with 15% styrene-butadiene-rubber latex (SBR) polymer. Forty-eight shear-designed and shear-deficient real-size beams were used in this experimental work. Ultimate shear load-carrying capacity of control beams was found at two different shear-span (a/d) ratios 1 and 3. The sets of remaining beams were loaded with different predetermined damage levels of 45%, 75%, and 95% of the ultimate load values and then strengthened with 20 mm thick PMF. The strengthened beams were then again tested for ultimate load-carrying capacity by conducting the shear load test at a/d = 1 and 3. As a result, the PMF-strengthened beams showed restoration and enhancement of ultimate shear load-carrying capacity by 5.90% to 12.03%. The ductility of strengthened beams was improved, and hence, the corresponding deflections were prolonged. On the other hand, the cracking pattern of PMF-strengthened beams was also improved remarkably.


Author(s):  
Ryoga Oura ◽  
Takashi Yamaguchi ◽  
Kentaro Arimura

<p>Bridges are composed by many structural members which interact with each other to resist against various load combinations. Considering damage repair of one of its structural members, the relationship between the recovery of the individual load-carrying capacity due to the repair of a single member and the improvement of the load-carrying capacity of the structural system is not clear. In the present study, a full-scale FE analysis has been conducted for a steel I-girder bridge system with corrosion damages which have been repaired. The analysis considered, the structural system behavior, varying the repaired areas and the type of patch members. From the analytical results, it was found that, compared to the method in which the damaged portion is completely repaired, the amount of repair can be reduced by taking into account the structural system behavior and partially repair both the damaged and the adjacent intact girders.</p>


2000 ◽  
Vol 1696 (1) ◽  
pp. 136-143 ◽  
Author(s):  
Andrzej S. Nowak ◽  
Junsik Eom ◽  
Ahmet Sanli

Application of field testing for an efficient evaluation and control of live-load effects on bridges is described. A system is considered that involves monitoring of various parameters, including vehicle weight, dynamic load component, and load effects (moment, shear force, stress, strain) in bridge components, and verification of the minimum load-carrying capacity of the bridge. Therefore, an important part of the study is development of a procedure for measuring live-load spectra on bridges. Truck weight, including gross vehicle weight, axle loads, and spacing, is measured to determine the statistical parameters of the actual live load. Strain and stress are measured in various components of girder bridges to determine component-specific load. Minimum load-carrying capacity is verified by proof load tests. It has been confirmed that live-load effects are strongly site specific and component specific. The measured strains were relatively low and considerably lower than predicted by analysis. Dynamic load factor decreases with increasing static load effect. For fully loaded trucks, it is lower than the code-specified value. Girder distribution factors observed in the tests are also lower than the values specified by the design code. The proof load test results indicated that the structural response is linear with the absolute value of measured strain considerably lower than expected. Field tests confirmed that the tested bridges are adequate to carry normal truck traffic.


2021 ◽  
Vol 11 (2) ◽  
pp. 101-106
Author(s):  
Rashid Hameed ◽  
Saba Mahmood ◽  
M. Rizwan Riaz ◽  
S. Asad Ali Gillani ◽  
Muhammad Tahir

Abstract This study is carried out to investigate the effectiveness of using externally applied epoxy mortar on joints of masonry wall panels to enhance their load carrying capacity under axial compressive and lateral loads. A total of six 113 mm thick masonry wall panels of size 1200 x 1200 mm were constructed for this study. Four out of six walls were strengthened using locally available CHEMDUR-31 epoxy mortar on joints. The remaining two walls were tested as control specimens. The control and strengthened wall panels were tested under axial compression and lateral loads. In axial compression test, out of plane central deflection and vertical strain at the center of wall panel were recorded while in lateral load test, in-plane lateral displacement of wall and horizontal strain at the center were recorded at each load increment. Failure pattern of each wall panel is also studied to notice its structural behavior. The results of this experimental study showed an increase of 45% and 60% in load carrying capacity under axial compression and lateral bending, respectively by the use of strengthening technique employed in this study.


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