Prediction of vertical deflections for a long-span prestressed concrete bridge structure

2005 ◽  
Vol 27 (12) ◽  
pp. 1820-1827 ◽  
Author(s):  
Ian N. Robertson
2010 ◽  
Vol 163-167 ◽  
pp. 1147-1156 ◽  
Author(s):  
Ali Fadhil Naser ◽  
Zong Lin Wang

The main purpose of damage inspection of the bridge components is to ensure the safety of a bridge and to identify any maintenance, repair, or strengthening which that need to be carried out. The essential damages that occur in reinforced concrete bridge include different type of cracks, scalling and spalling of concrete, corrosion of steel reinforcement, deformation, excessive deflection, and stain. The main objectives of this study are to inspect the appearance of Jiamusi highway prestressed concrete bridge and describe all the damages in the bridge structural components, and to evaluate the structural performance of the bridge structure under dead and live loads. The field tests that are adopted in this study are the depth of concrete carbonation test, compressive strength of concrete test, corrosion of steel reinforcement test, and static load test. According to inspection of the bridge structure appearance, the overall states of bridge structure in good and there are not serious damages, but there are diagonal and longitudinal cracks in the inside web of box girder within block No.8 and 9. Expansion joints suffer from serious damage such as deformation of expansion joint rubber, dislocating, shedding, and cracking. The field test results show that the concrete of the bridge structure has not carbonation; the strength of concrete in good state; there is not corrosion in steel reinforcement; The values of load test for vertical deflection, strain, and stress are less than the theoretical values and the results of cracks observation show that there is not changing in the length of diagonal cracks in the web of box girder when the load test is applied. This indicates that the working state and carrying capacity of the bridge structure in good state.


2011 ◽  
Vol 189-193 ◽  
pp. 2346-2352
Author(s):  
Ali Fadhil Naser ◽  
Zong Lin Wang

Fu Feng highway prestressed concrete bridge is located in Changchun City which is the capital and largest city of Jilin province and it located in the northeast of China. The strengthening of the bridge structural members can be attempted by replacing poor quality or defective materials by better quality materials, attaching additional load-bearing materials, and re-distribution of the loading actions through imposed deformation on the structure system. The objectives of this study are to explain the strengthening process of damaged structural members of Fu Feng bridge, and to evaluate the performance of the bridge structure by adopting static load test. The strengthening process of damaged structural members includes three stages. These stages include the strengthening of box girders floor by casting of 10cm of reinforced concrete in the floor of box girder within the location of positive bending moment in the mid-span and edge span, the strengthening of box girders web by pasting steel plates in the inside of the right and left of box girders, and the strengthening of the transverse beam of piers No. 18 and No. 19 by using carbon fiber sheet. The results of static load test show that the values of testing coefficient ( ) of stress range from 0.83 to 0.92 are less than allowable value 1.05. Therefore, these values satisfy the allowable value of standard, indicating that the structural member has a certain strength reserve and the working state of the bridge structure in good state. the ratio between the measured and theoretical deflection is 1.41 and 1.68 for condition 3 more than allowable value 0.8, indicating that the state of stiffness is not good and there are still a serious shortage in stiffness of structure. Therefore, this study recommended that the bridge structural members need to re-strengthen by using other effective technical and materials to increase the stiffness of structural members of the bridge.


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