scholarly journals Shear Assessment of Existing Prestressed Box Girder Bridge

2021 ◽  
Vol 1203 (2) ◽  
pp. 022131
Author(s):  
Jaroslav Baran ◽  
Viktor Borzovič ◽  
Žaneta Šenšelová
Keyword(s):  
Cross Section ◽  
Prestressed Concrete ◽  
Parametric Study ◽  
Historical Development ◽  
Shear Resistance ◽  
Concrete Bridge ◽  
Shear Reinforcement ◽  
Box Girder ◽  
Internal Forces ◽  
Post Tensioned

Abstract The paper deals with the shear assessment of existing prestressed concrete box-girder bridges. Mainly focuses on the historical development of technical standards used in the design of prestressed concrete road bridges in the Slovak Republic. The standards for bridge design have been amended several times. A parametric study was performed on a model post-tensioned concrete bridge with a box-girder cross-section, which compares the internal forces along the length of the bridge using various standards and technical regulations., The differences in design principles and shear capacity were investigated while the amount and geometry of the longitudinal prestressing of the bridge were the same for all cases. Case of study is a road three-span post-tensioned concrete bridge with a main span of 50 m and end spans of 40 m. The single box-girder cross section height is constant of 2.5 m. The bridge is straight without any curvature in the horizontal plane. The thickness of the bottom slab is variable near the inner supports. The prestressing is formed by 19-strands tendons with a strand diameter of 15.7 mm with a polygonal cable geometry. The numerical model is considered as a beam element with neglecting of the torsional effects of the load. The parametric study points out the differences in the internal forces with use of different design regulations and standards. It also focuses on the shear resistance of the walls of the box-girder cross-section of the bridge. Differences in design methods are presented by the required area of shear reinforcement in the wall of box cross-section. The aim of the study is to point out the historical development of design from the point of view of shear resistance of prestressed bridges. When assessing existing older bridges and trying to achieve reliability according to the current Eurocodes, there is subsequently a requirement for additional shear reinforcement.

scholarly journals Comparison of the level of required prestressing of road bridges according to the historical development of technical standards in Slovakia

2021 ◽  
Vol 1209 (1) ◽  
pp. 012054
Author(s):  
J Baran ◽  
V Borzovič
Keyword(s):  
Prestressed Concrete ◽  
Parametric Study ◽  
Historical Development ◽  
Slovak Republic ◽  
Traffic Load ◽  
Normal Stresses ◽  
Technical Standards ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges

Abstract The paper deals with the level of required prestressing designed for box-girder bridges. Mainly focuses on the development of standards used in the design of prestressed concrete road bridges in the Slovak Republic. The standards for bridge design have been amended several times. A parametric study was performed on a model post-tensioned concrete bridge with a box-girder cross-section. The bridge has three-span with a main span of 50 m and end spans of 40 m. The study compares the normal stresses caused by traffic load along the length of the bridge according to various standards and technical regulations. The differences in design principles were investigated while the amount and geometry of the longitudinal prestressing of the bridge were changed as required by corresponding standards. The numerical model is considered as a beam element with neglecting of the torsional effects of the load. The parametric study points out the differences in the normal stresses along the bridge according to different design regulations and standards. The aim of the study is to compare level of prestressing according to the historical development of prestressed bridges

Querkrafttragfähigkeit von Brückenträgern aus Spannbeton mit geringen Querkraftbewehrungsgraden/Shear Capacity of Prestressed Concrete Bridge Girders with Small Shear Reinforcement Ratios

Bauingenieur ◽  
2020 ◽  
Vol 95 (11) ◽  
pp. 397-407
Author(s):  
Viviane Adam ◽  
Martin Herbrand ◽  
Josef Hegger
Keyword(s):  
Prestressed Concrete ◽  
Shear Capacity ◽  
Bridge Girders ◽  
Concrete Bridge ◽  
Shear Reinforcement ◽  
Prestressed Concrete Bridge ◽  
Small Shear

Zusammenfassung Neben gestiegenen Verkehrslasten führen strengere normative Regeln zu höheren Anforderungen an Spannbetonbrücken. Viele ältere Spannbetonbrücken im Bestand weisen daher rechnerische Defizite bei der Querkrafttragfähigkeit auf. Durch experimentelle und theoretische Untersuchungen konnten im Zuge eines Forschungsprojekts für die Bundesanstalt für Straßenwesen (BASt) verfeinerte Berechnungsansätze für Querkraft erarbeitet werden. In diesem Beitrag werden am Institut für Massivbau der RWTH Aachen (IMB) durchgeführte Großversuche an Spannbetondurchlaufträgern vorgestellt. Die Träger mit Rechteck- oder I-Profil wiesen geringe Querkraftbewehrungsgrade auf und wurden durch Gleichstreckenlasten beansprucht. Auf Basis der Forschungsergebnisse wurde ein verfeinertes Bemessungsmodell entwickelt, das aus einem modifizierten Fachwerkmodell mit additivem Betontraganteil besteht und gegenüber dem Ansatz nach aktueller Nachrechnungsrichtlinie weitere Querkrafttragreserven berücksichtigt.

Aesthetic Design of Odawara Port Bridge

1996 ◽  
Vol 1549 (1) ◽  
pp. 108-113
Author(s):  
Tsuguo Oishi ◽  
Yasuo Inokuma
Keyword(s):  
Cross Section ◽  
Prestressed Concrete ◽  
Surrounding Area ◽  
Box Girder ◽  
Aesthetic Design ◽  
Cable Stayed Bridge ◽  
The World ◽  
Bridge Type ◽  
Main Girder ◽  
Tower Height

The Odawara Port Bridge is located at the mouth of Odawara Port. Selecting a bridge type that symbolized the entire project and blended well with the surrounding area was critical. To achieve this, an extra-dosed prestressed concrete box girder with a main span of 122 m was selected. Construction of this bridge type is the first in the world. Special characteristics of this bridge type are a lower tower height than that of a cable-stayed bridge, the use of a saddle at the top of the towers, and the incorporation of epoxy-coated strands for diagonal cables. The design of the various sections of the bridge was achieved by integrating the characteristic shape of the towers with cable profiles while establishing horizontal continuity with the main girder. As a result of the integration process, the following design objectives were adopted: (a) constant main girder depth; (b) inverted trapezoidal main girder cross section; (c) towers without a connecting beam at the top; (d) a fan-shaped saddle; (e) compact cable vibration dampers; (f) graded metallic coloring of cables; (g) integrated steel railing and road surface lighting; (h) nighttime bridge lighting, and (i) encased drainage pipes.

Monitoring of External Prestressing Tendons Construction Process of Jiamusi Highway Prestressed Concrete Bridge during Strengthening in China

2010 ◽  
Vol 163-167 ◽  
pp. 2873-2879
Author(s):  
Ali Fadhil Naser ◽  
Zong Lin Wang
Keyword(s):  
Prestressed Concrete ◽  
Concrete Bridge ◽  
Construction Process ◽  
Box Girder ◽  
External Prestressing ◽  
Maximum Value ◽  
External Tendons ◽  
Monitoring Process ◽  
Left And Right ◽  
Prestressed Concrete Bridge

Jiamusi highway prestressed concrete bridge is located in the Jiamusi City within Heilongjiang province in the east north of China. The strengthening and repairing of the bridge structure can be provided an effective and economic solution in appropriate situation. The objective of this study are to monitor the construction process of external prestressing tendons for strengthening of Jiamusi highway prestressed concrete bridge. Monitoring process includes measurement of external prestressing tendons natural frequency, monitoring of tensile forces values of external prestressing tendons, monitoring of development of anchor beams cracks, and monitoring of anchor beam deformation. The results of monitoring process show that the box girder No. 11 has the largest values of proportional coefficient (K) and the maximum value is 327.8. Box girder No. 8 has the largest values of frequency, the maximum value is 3.499. Five levels of tension are used in the application of tensile force in the tension process of external prestressing tendons. These levels are level 1=248.2kN, level 2=496.4kN, level 3=744.6kN, level 4=992.8kN, and level 5=1241kN. The measured tendons elongation values of left box girder No.8 are more than the theoretical values. For left and right box girder No. 9, side external tendons of left box No. 10, and left and right box girder No. 11, the measured values are less than theoretical values of elongation. After tension process, there are no new cracks in the top, web, and bottom of anchor beam and a small number of cracks developed slightly. These cracks are found around ducts of external tendons. The length of cracks rang from 0.03m to 0.5m and width rang from 0.05 mm and 0.25mm. The longitudinal deformation of the interface and top of anchor beam is very small, ranging from 0.001mm to0.115mm, which averaged 0.026mm. The overall state of anchor beams and box girders during strengthening is good.

scholarly journals Effect of Time Dependent Variables on Different Types of PSC Box Girder Bridges.

2019 ◽  
Vol 11 (02) ◽  
pp. 123-128
Author(s):  
Norine George ◽  
Kiran Umachagi ◽  
Sunil Kumar Tengli
Keyword(s):  
Cross Section ◽  
Prestressed Concrete ◽  
Cell Types ◽  
Time Dependent ◽  
Box Girder ◽  
Temperature Creep ◽  
Dependent Variables ◽  
Concrete Box Girder ◽  
Girder Bridge ◽  
Creep And Shrinkage

Time dependent variables such as temperature gradient, effective temperature, creep, and shrinkage lead to long term deflection in prestressed concrete girders. This in turn effects the serviceability and sustainability of the bridge in the long run. Therefore, research and analysis is of paramount importance before deciding the type of girder to be used. A parametric study was carried out in order to determine the most desirable and efficient type of box girder to be used for a prestressed concrete bridge having a continuous span. Three prestressed concrete box girder bridge models of single, multi-cell rectangular and multi-cell trapezoidal cross section, having similar span, width and depth were taken into consideration. The finite element models were analysed using MIDAS Civil. The behaviour of the box girder cell types under various time dependent properties such as temperature, creep and shrinkage are presented in this paper. The results show that the prestressed concrete box girder bridge of multi-cell rectangular cross section exhibits greater forces and moments due to time dependent variables in comparison to the other two box girder cell types.

Field Damage Inspection and Static Load Test Analysis of Jiamusi Highway Prestressed Concrete Bridge in China

2010 ◽  
Vol 163-167 ◽  
pp. 1147-1156 ◽  
Author(s):  
Ali Fadhil Naser ◽  
Zong Lin Wang
Keyword(s):  
Prestressed Concrete ◽  
Steel Reinforcement ◽  
Load Test ◽  
Concrete Bridge ◽  
Bridge Structure ◽  
Static Load Test ◽  
Box Girder ◽  
Good State ◽  
Prestressed Concrete Bridge ◽  
Corrosion Of Steel

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.

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