REMAINING STRENGTH EVALUATION OF PLATE GIRDERS WITH CORROSION NEAR SUPPORTS

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Naoyuki Asao ◽  
Katashi Fujii ◽  
Hiroaki Fukuda ◽  
Ryuichi Yokota
Keyword(s):  
Shear Strength ◽  
Evaluation Method ◽  
Surface Condition ◽  
Bottom Flange ◽  
Strength Evaluation ◽  
Railway Bridges ◽  
Plate Girders ◽  
Vertical Stiffener ◽  
The 1960S ◽  
The Web

In Japan, a lot of steel railway bridges were constructed during the period of rapid economic growth in the 1960s. Now, since over 50 years have passed, the aging of these structures has become conspicuous and a major social problem. In particular, for steel plate girders with open deck system, deterioration and damage due to corrosion is becoming obvious. Moreover, the remaining strength evaluation method of corroded structures is not always sufficient. Therefore the purpose of this study is to propose an analytically-based evaluation method for the maintenance of steel railway bridges. The following are noted: 1) Regarding the shear strength of plate girders with corrosion near supports, the remaining strength depends on the corroded surface condition of each component such as a web or a vertical stiffener. And, according to the form and degree of corrosion, the fracture mode also changes from the buckling of web to the buckling of cross-shape column consisting of the web and vertical stiffener. The result shows that the corroded web has more effect on the shear strength than the vertical stiffener. 2) Regarding the peeling between the web and bottom flange due to corrosion near supports, the remaining strength is deteriorated more rapidly than above case 1, when the peeling range lengthens more than the sole plate area.

STRENGTH RECOVERY OF STEEL BRIDGES WITH CORROSION NEAR BEARINGS

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Naoyuki Asao ◽  
Yoshiichi Fujimoto
Keyword(s):  
Steel Plate ◽  
Shear Capacity ◽  
Analytical Models ◽  
Plate Girders ◽  
Girder Bridges ◽  
Strength Recovery ◽  
Reinforcement Measure ◽  
Vertical Stiffener ◽  
The 1960S ◽  
Plate Girder

A lot of steel plate girder bridges were erected during the rapid growth in the 1960s in Japan. Currently, the condition of those aging bridges has become marked and a problem in society since over 50 years have passed. Particularly, the corrosion-induced deterioration and damage in railway steel plate girder bridges, which have an open deck, is becoming prominent. Despite that, the evaluations of residual strengths and the strengthening methods of corroded bridges are not always enough. Therefore, firstly, this paper shows analytical-based evaluation results that explain how the residual shear capacities of plate girders, having corrosion near bearings, depend on the condition of the corroded surface, such as a vertical stiffener or a web. The results show the fracture mode as buckling changes as well as the residual shear capacity, according to the degree and form of corrosion. Next, this study proposes a reliable reinforcement measure to recovery the shear capacity by applying said evaluation results and analytical models. Finally, the shear capacity could be improved tremendously by simple attachments as reinforced members.

Development of Structural Condition Index to Support Pavement Maintenance and Rehabilitation Decisions at Network Level

2003 ◽  
Vol 1827 (1) ◽  
pp. 10-17 ◽  
Author(s):  
Zhanmin Zhang ◽  
German Claros ◽  
Lance Manuel ◽  
Ivan Damnjanovic
Keyword(s):  
Evaluation Method ◽  
Surface Condition ◽  
Condition Index ◽  
Structural Condition ◽  
Pavement Management ◽  
Structural Deformation ◽  
Pavement Maintenance ◽  
State Highway ◽  
Structural Reinforcement ◽  
Maintenance And Rehabilitation

Every year, state highway agencies apply large amounts of seal coats and thin overlays to pavements to improve the surface condition, but these measures do not successfully address the problem. Overall pavement condition continues to deteriorate because of the structural deformation of pavement layers and the subgrade. To make effective decisions about the type of treatment needed, one should take into consideration the structural condition of a pavement. Several different structural estimators can be calculated by using falling weight deflectometer data and information stored in the Pavement Management Information System (PMIS) at the Texas Department of Transportation. The analysis considers pavement modulus and structural number as the structural estimators of a pavement. The evaluation method is based on the sensitivity of the structural estimators to deterioration descriptors. The deterioration per equivalent single-axle load of all major scores stored in the Texas PMIS is proposed as the primary indicator of pavement deterioration. In addition, the use of the structural condition index is recommended as a screening tool to discriminate between pavements that need structural reinforcement and those that do not. This index is calibrated for use in maintenance and rehabilitation analysis at the network level.

scholarly journals Shear Strength Evaluation of Al2O3/SUS 304 Joints at Elevated Temperatures.

1999 ◽  
Vol 65 (637) ◽  
pp. 1902-1907
Author(s):  
Masaaki MATSUBARA ◽  
Isao ITOH ◽  
Kenji SAKAMOTO ◽  
Mitsuaki KOTANAGI ◽  
Kunihiko YOSHIKAWA
Keyword(s):  
Shear Strength ◽  
Elevated Temperatures ◽  
Strength Evaluation
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