PC Bridge Research Articles

AEM analysis of asphalt pavement on PC bridge under the coupling effect between impact from ruptured vertical PC bars and temperature

The resistance of asphalt pavement against impact loading from corrosion-induced ruptured vertically tightened PC bars in PC bridges is critical for traffic safety. When vertically tightened PC bars in PC girders rupture, they protrude from the anchorage section and damage the asphalt pavement, which may cause severe accidents. In this study, the performance of a two-layered asphalt pavement system under the coupling effect between impact and temperature, with the impact caused by a vertically tightened PC bar with 4,408 J impact energy at 50 °C and 0 °C, was investigated. A 3D Applied Element Method (AEM) model was developed for simulating asphalt pavement at 50 °C and 0 °C under 4,408 J impact energy. The numerical simulations were verified based on the experimental results. The numerical simulation results showed that the asphalt pavement system used in this study at 50 °C and 0 °C can withstand 4,408 J impact energy. Further, AEM numerical simulation with appropriate modeling demonstrated the effectiveness of an asphalt pavement system with appropriate material and thickness in preventing protrusion of PC bar.

Model assessment of a bridge by load and dynamic tests

The assessment and monitoring of structures through in situ tests, especially dynamic tests, is becoming a common procedure due to the evolution of the instruments and numerical processing of data. However, the use of the data based on the supervised approach, which requires engineering knowledge of the structure is needed before assessing the numerical model that will be the “digital twin” model of the construction for future analysis, monitoring and upgrading of the structure. This process is very complex and requires strong competence in the field of structural engineering, but it allows a real reference for the periodic check of the structure health with a method to also define a solution for its maintenance and upgrade. In this paper, a case study of a PC bridge designed by Riccardo Morandi in 1952–1955 is proposed to apply the process of updating a numerical model by static and dynamic in situ tests. The process based on the two different types of tests was separately conducted to evaluate the efficiency and the difference in the results. The main results of the two types of tests overlap for most features, but specific evidenced aspects that are observed have to be considered.

Analysis of influence of concrete stiffness reduction on mid-span deflection of PC box girder bridge

At present, the concept of bridge preventive maintenance has been widely used. In order to find the right time for PC bridge maintenance and make better maintenance decision, it is necessary to predict the service performance of PC bridge. In this paper, the service performance of PC bridge is divided into several indexes, and the fuzzy neural network method is used to calculate these indexes data. Taking shangtan bridge as an example, the maximum relative error between the measured value and the predicted value is found to be within 5%, which meets the accuracy requirements. The feasibility of this method is verified and provides guidance for the future decision-making of bridge maintenanc.

The Feature of the Corrosion of Steel in Existing PC Bridge and Case of the Repair Method Considering Durability

The Feature of the Corrosion of Steel in Existing PC Bridge and Case of the Repair Method Considering Durability

サスティナビリティを追求したPC橋梁の試み

CO2排出削減と維持管理性の向上を狙い，セメントを用いることなく高強度で低収縮を実現したコンクリート（以下，サスティンクリート）と，錆びないアラミドFRPロッドを組み合わせて，環境負荷の小さい長寿命なPC橋梁を実用化した。サスティンクリートは，蒸気による促進養生により材齢6日で150MPaという超高強度を発現すること，また，模型梁の載荷試験結果から，曲げ挙動やせん断耐力は，一般の高強度繊維補強コンクリートと同様の方法で評価できることを明らかにした。本稿では，短繊維補強したサスティンクリートの開発とプラントでの製造，プレテンション桁の架設と構造の検証，モニタリングまで一連の検討とその結果について報告する。

CONSIDERATIONS ON THE APPLICATION OF EUROCODES 2 AND 4 FOR CONCRETE BRIDGES

The application of certain parts of Eurocodes may result in surprising conclusions. Three independent examples of code requirements are presented. A first striking example is the fatigue compression resistance of RC or PC bridge girders and the prediction of the resulting lifetime, which may be excessively low. The second issue concerns the limiting value of slenderness of concrete arches, which shows no logical relation to the load bearing capacity. An alternative for the definition of slenderness is proposed. The third item is the necessity to consider an uplift force in the design of connectors, thus excluding virtually the use of block connections. In all three cases, alternatives are being proposed, needing further research or allowing a different approach to these issues. In addition, clarification of some code recommendations may overcome misunderstanding or erroneous application.

Analytical Study on Seismic Response Reduction for PC Bridge: Effects of Cost on a Proposed Seismic Reinforcement Method Due to Collision

After the 1995 Kobe strong earthquake, it has been greatly revised in Japanese highway bridge codes. It was secured a large gap size of the girder for the collision of girders by the Level 2 Earthquake Ground Motion of the seismic design. However, if a large gap size of the girder is adopted, the expansion joint have to be largely changed. Furthermore, the construction costs and the seismic reinforcement costs will be increased. It was considered that the gap reduction allowing the collision of girders, as a premise of preventing the collapse of the bridge, was one of the seismic reinforcement method in order to decease the construction costs and the seismic reinforcement costs. In addition, it is necessary that damage of the girder end and the pier bottom is decreased by attaching rubber shock absorber to the end of girder. In order to reduce gap size between girders, it is necessary that the resistance characteristics of the abutment due to the collision of girders and the dynamic response characteristics due to the damping at the bottom of pier are grasped. Although many studies on the collision phenomenon of bridge girders have been published, the effects of cost on seismic reinforcement allowing the collision of PC bridge girders have not been sufficiently considered yet. In this study, the resistance characteristics of the abutment due to the collision of girders and the dynamic response characteristics due to the damping at the bottom of pier will be verified by carrying out dynamic response analysis that the 3-dimensional finite element model (3D-FEM) of the PC bridge was built. In addition, the effects of cost on the proposed seismic reinforcement allowing the collision of concrete bridge girders will be considered. From the comparison of the total cost on both the current method and the proposed one, it will be confirmed that the proposed seismic reinforcement method is very effective.

Precast bridge construction with UHPFRC—Shear tests and railway bridge pilot application

AbstractDue to the favorable material properties, Ultra‐High Performance Fiber‐Reinforced Concrete (UHPFRC) opens up new potential for precast options in PC bridge construction. On that matter, this article outlines the application, the load‐bearing behavior and advantages of two different possibilities: slender prestressed bridge girders and a prestressed trough‐shaped bridge element. Prestressed bridge girders made of UHPFRC allow for the realization of very slender cross‐sections with thin webs. For these beams, the shear capacity is the governing design issue. Hence, further investigations on the shear behavior with a variation of the fiber content, the prestressing level as well as the amount of shear reinforcement were undertaken. In this context, also size effects were examined using specimens with different construction heights up to 1.0 m. To enable testing of a high number of specimens with realistic cross‐sectional dimensions and at reasonable effort, an innovative experimental setup was developed and used for the investigations. Apart from these laboratory tests the present article deals with the pilot application of a railway bridge made of UHPFRC in Germany. The design and construction process as well as measurement results of the load and deformation behavior of the prestressed precast bridge element are presented and discussed.

Maintenance of Existing PC Bridges with Cracks along PC Cables

Maintenance of Existing PC Bridges with Cracks along PC Cables

Effective Approach to Maintenance at the Time of Construction of a Maritime PC Bridge

Effective Approach to Maintenance at the Time of Construction of a Maritime PC Bridge

PC 교량의 공극 검출을 위한 시멘트/탄소나노튜브 복합재료의 전기적 검측 성능 분석

PC 교량의 공극 검출을 위한 시멘트/탄소나노튜브 복합재료의 전기적 검측 성능 분석

Risk Assessment about the Maintenance of the PC Bridge in Tozai Line

Risk Assessment about the Maintenance of the PC Bridge in Tozai Line

Structural Behaviors of Large Span Prestressed PC Bridge Stiffened by CFST Arch

High-speed railway system has been developed with unprecedented pace in recent decades. Various type of bridges (elevated structures) were built for high speed railway infrastructure due to land saving and sound operational condition provided. In this paper, the detailed modeling of the prestressed concrete girder stiffened by concrete filled steel tubular (CFST) arch was developed. Displacement, static stress, dynamic characteristics was obtained by analysis. The overall structural performance has been concluded.

Experimental Study on Vibration Characteristics of Prestressed Concrete Beam

In recent years, fractures in PC rods of expressway PC bridges have been reported in Japan. These breakages could lead to bridge collapse in a worst- case scenario. In our study, we have carried out vibration tests on a model PC beam to clarify how vibration characteristics of PC beams change when the applied prestress of the PC rod is lowered and develop a simple and effective method of checking PC bridge health. In the experiment, we used a PC beam that allow the degree of prestress to be changed and tested the beam applying forced vibration at first vibration mode. As a result, we saw that as prestress lowered, the natural frequency of PC beam lowered, but the vibration damping performance increased. The tendency of the results is close to that of the theoretical value, and therefore, the test results are considered valid. From the above, we can see that lowering of prestress caused by fractures of PC rod can be estimated by looking at the vibration characteristics of PC beams.

Loading test and numerical simulation of the residual strength of post-tension PC bridge damaged by chloride attack

Loading test and numerical simulation of the residual strength of post-tension PC bridge damaged by chloride attack

Investigation of Seismic Response on Girder Bridges: The Effect of Displacement Restriction and Wing Wall Types

In the seismic design specified by Japanese Specifications of Highway Bridges (JSHB), a large gap size between two adjacent girders or the girder and abutment has recommended to be constructed in the concrete girder bridge with multi-spans in order to prevent the collision, when it is subjected to Level 2 ground motion. However, the adoption of large gap into PC bridge will increase the construction and seismic reinforcement costs since relatively large expansion joints have to be used. Also, it causes the girders falling in the presumption of strong earthquake. It has been suggested that allowing the girder collision at the abutment by restricting the girder bridges displacement, the size of expansion joints can be reduced. These conditions are able to reduce the seismic design and seismic reinforcement cost.Although many studies on the effect of the collision have been published, the effect of displacement restriction of girders is still remains to be elucidated. This present study aims to investigate the seismic response of concrete girder bridges taking into account the effect of displacement restriction of girders allowing the girder collision at the abutment and the wing wall. Two span concrete girder bridge was examined in theoretically by 3D FEM model of ABAQUS with four different approaches at the wing wall abutment model. The dead load and soil pressure were calculated based on JSHB loading conditions and gap between superstructure and parapet wall was chosen to be 10cm and 20cm. Level 2 earthquake ground accelerations were applied horizontally at the bottom of pier. The numerical results showed that the parameters such as shear stress, response stress, displacement, and cracking were affected by displacement restriction and different wing wall model. Installing of the wing wall in abutment generally increased the response stress in parapet wall and shear stress around vertical wall of abutment. In contrast, it significantly reduced the horizontal displacement of abutment.

Failure by corrosion in PC bridges: a case history of a viaduct in Italy

Purpose The paper illustrates a viaduct collapse due to corrosion phenomena. Moreover, a contribution to the issues related to both the control of existing structures and design methods to be followed for the construction of new buildings is provided. Design/methodology/approach The objectives were achieved by in situ observations and numerical analyses. The effects of corrosion phenomena are investigated, and the progressive collapse analysis is provided to be helpful in this case. Findings The damages induced by corrosion phenomena have caused the collapse of the viaduct taken in to account. The performed numerical analyses were able to reproduce the effects of corrosion in terms of reduction of wires diameter. Research limitations/implications The research is limited to prestressed concrete viaduct with post-tensioned cables. Practical implications A monitoring plan, subdivided in several phases, is suggested, to avoid critical situations as these described. Originality/value The case study brought useful information on the effects of corrosion on the decks section, showing how the technology in post-tensioned cables is usually insidious and prone to the issues relating to corrosion of the wires

波形鋼板ウェブPC橋の技術開発

波形鋼板ウェブPC橋の技術開発

「PEシースを用いたPC橋の設計施工指針（案）」の制定とその内容について

平成27年8月に，（公社）プレストレストコンクリート工学会より「PEシースを用いたPC橋の設計施工指針（案）」が発刊された。この指針は，ポリエチレン（PE）シースを有効かつ適切に使用してプレストレストコンクリート（PC）橋の品質を高めることを目的とし，PEシース自体の性能，品質のみならず，その諸特性を踏まえたPC橋の設計，施工，品質管理・検査の方法を示したものである。本稿は，新たに制定したこの指針の内容と，制定にあたっての検討成果の要点について概説するものである。

Fundamental study on the simplified analytical method of PC bridges

Fundamental study on the simplified analytical method of PC bridges