scholarly journals Experimental Study on Strengthening Effect Analysis of a Deteriorated Bridge Using External Prestressing Method

2021 ◽  
Vol 11 (6) ◽  
pp. 2478
Author(s):  
Sang-Hyun Kim ◽  
Jong-Sup Park ◽  
Woo-Tai Jung ◽  
Tae-Kyun Kim ◽  
Hee-Beom Park

The external prestressing method was developed to improve the load carrying capacity of concrete bridges damaged by ageing or other external environmental factors. Therefore, it is necessary to examine the performance of the structure before and after strengthening, and verification and confirmation of the actual strengthening effect should be preceded. However, for reasons such as securing deteriorated bridges and the absence of design data, the strengthening effect of an actual bridge is rarely analyzed. Hence, in this study, the strengthening effect was verified by conducting a set of material property tests and four-point loading tests before and after strengthening of an actual bridge, which had been utilized for over 45 years. As a result, it was determined that confirming the strengthening effect before cracking is challenging due to the nature of the external prestressing method, which has an insignificant effect on the stiffness; however, the effect of increasing the crack load of the external prestressing method was experimentally verified. The result of the study is expected to contribute to the determination of the load carrying capacity and required strengthening amount when strengthening existing prestressed concrete girder bridges.

2017 ◽  
Vol 738 ◽  
pp. 100-109
Author(s):  
Josef Vican ◽  
Peter Kotes ◽  
Martin Moravcik ◽  
Jaroslav Odrobinak

The handbook "Determination of load-carrying capacity of railway bridges" [1] has grown up due to updating of old Slovak guideline [2] taking into account Eurocodes. In the case of railway bridges, there are about 2300 bridges in Slovakia and about 78 % of them are from concrete or masonry. About 28 % of bridge total number is older than 77 years and about 18 % of them are even older than 100 years. Therefore, there is need to make regular inspections, recalculate them – determine of load-carrying capacity and then to decide, which of them should be repaired or reconstructed [3,4]. The paper presents general concepts and basic assumptions for determining the load-carrying capacity of reinforced and prestressed concrete railway bridges. In contrast to design of a new bridge, additional data related to existing bridge condition and its behaviour like information from regular inspections and real state of degradation can be taken into account. Special recommendation and allowances for global analysis of existing concrete superstructures for the purpose of the load-carrying capacity estimation are discussed, as well.


1983 ◽  
Vol 105 (1) ◽  
pp. 48-63 ◽  
Author(s):  
C. Bagci ◽  
A. P. Singh

The effect of the film shape on the load carrying capacity of a hydrodynamically lubricated bearing has not been considered an important factor in the past. Flat-faced tapered bearing and the Raileigh’s step bearing of constant film thickness have been the primary forms of film shapes for slider bearing studies and design data developments. This article, by the computer aided numerical solution of the Reynolds equation for two dimensional incompressible lubricant flow, investigates hydrodynamically lubricated slider bearings having different film shapes and studies the effect of the film shape on the performance characteristics of finite bearings; and it shows that optimized bearing with film shapes having descending slope toward the trailing edge of the bearing has considerably higher load carrying capacity than the optimized flat-faced tapered bearing of the same properties. For example the truncated cycloidal film shape yields 26.3 percent higher load carrying capacity for Lz/Lx = 1 size ratio, and 44 percent higher for Lz/Lx = 1/2. The article then presents charts for the optimum designs of finite slider bearings having tapered, exponential, catenoidal, polynomial, and truncated-cycloidal film shapes, and illustrates their use in numerical bearing design examples. These charts also furnish information on flow rate, side leakage, temperature rise, coefficient of friction, and friction power loss in optimum bearings. Appended to the article are analytical solutions for infinitely wide bearings with optimum bearing characteristics. The computer aided numerical solution of the Reynolds equation in most general form is presented by which finite or infinitely wide hydrodynamically or hydrostatically lubricated bearings, externally pressurized or not, can be studied. A digital computer program is made available.


Author(s):  
Xiandong Liao ◽  
Xiang Hu

The seismic performance of the internal connection of precast prestressed concrete frame was studied systematically, based on the experiment of full-scale model under low cyclic reversed loading. This study was mainly focused on failure pattern, load-carrying capacity, skeleton curves, and hysteresis curves. Furthermore, a nonlinear finite element analysis using Abaqus was carried out to study the characteristics of the internal connection of precast prestressed concrete frame. Results revealed that the damage was concentrated mainly on beam end owing to flexural action, while steel bars in the columns and stirrups in the core region remained elastic until failure occurred. The calculated value of the load-carrying capacity of the internal connection was similar to the experimental one. Present study can be referenced for the application of precast prestressed concrete frame in high seismic zones.


1994 ◽  
pp. 83-92
Author(s):  
Yoshimi Sonoda ◽  
Nobutaka Ishikawa ◽  
Keiichiro Sonoda ◽  
Toshiaki Ohta

2013 ◽  
Vol 753-755 ◽  
pp. 520-524
Author(s):  
Xin Zhao

Taking a flyover as the background, this paper compares two reinforcement scheme, and ultimately chooses the paste carbon fiber polymer method to reinforce the bridge. It calculates and analyzes the structure before and after the reinforcement, then compares the stress state , shear load-carrying capacity and flexural capacity. At last ,it evaluates the effect of the paste carbon fiber polymer method and puts forward some suggestions.


2014 ◽  
Vol 22 (6) ◽  
pp. 543-551
Author(s):  
Renildo Luiz Mion ◽  
Virginia Pires Pereira ◽  
Webert Alan Sombra ◽  
Karla Lúcia Batista Araújo ◽  
Silvia Ferreira da Silva

The load carrying capacity of the soil can be determined from preconsolidation curves, being sensitive to the variation of loads and extremely sensitive to changes in soil moisture. For this study, the water content in soil was 2.50% and 10.58% for the layer from 0 to 0.15 m. Soil samples were collected before and after traffic with one and two passes of a tractor weighing 7100 kg, equipped with 14.4-24 R1 bias tires on the front with inflation pressure of 82.74 kPa and 18.9-34 R1 rear tires with inflation pressure of 96.53 kPa, and a tire ground contact area of 0.11 m2 and 0.13 respectively for the front and rear tires. The speed at the time of the pass for each treatment was 2.22 m s-1. Regardless of the soil water content, the load carrying capacity increases with the traffic of machines due to reduction of voids. Preconsolidation curves should be used with caution due to the use of samples for determining the points in saturated conditions, and when recommended for load-bearing capacity, unsaturated samples should be used.


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