scholarly journals Flexural Behavior of Unbonded Prestressed Concrete Bridge Girders

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Chenhao Tang ◽  
Gang Zhang ◽  
Chaojie Song ◽  
Xuyang Li ◽  
Yonggang Hou
Keyword(s):  
Prestressed Concrete ◽  
Three Dimensional ◽  
Bridge Girders ◽  
Flexural Behavior ◽  
Design Parameters ◽  
Four Point Bending ◽  
Dimensional Finite Element ◽  
Prestressing Strands ◽  
Prestressed Concrete Bridge ◽  
Three Dimensional Finite Element

This paper presents an experimental and numerical investigation on the flexural behavior of unbonded prestressed concrete (PC) T bridge girders. Three unbonded PC T bridge girders with different prestress degrees spanning 3 m were selected to perform four-point bending tests and then determine the flexural performance. Flexural capacity, crack development and failure mode, load-deflection curves, strain in longitudinal rebars, and stress in prestressing strands of unbonded PC T bridge girders are experimentally analyzed. Subsequently, three-dimensional finite element (FE) models are built and validated by experiments to investigate the effect of different design parameters on flexural behavior of bridge girders. Results generated from experiment and numerical studies show that the flexural destruction behavior in unbonded PC T bridge girders experiences elastic, elastic-plastic, and ductility stages, similar to that of PC T bridge girders. The prestress degree and load location have significant influence on the destruction process in unbonded PC T bridge girders. A lower effective prestress degree can reduce the distribution range in cracks and also increase the width of cracks. Stress in prestressing strands under anchor increases rapidly after concrete presents obvious cracks, and the fracture area within prestressing strands increases with the elevation of prestress degree. The aim of this study is to provide a reference for the design and practical application of unbonded PC T bridge girders.

Comparative Analysis of Several Construction Scheme of a Large-Sized Tie-Arch Aqueduct

2011 ◽  
Vol 94-96 ◽  
pp. 2350-2354
Author(s):  
Shu Zhong Lei ◽  
Zhong Xin Wang ◽  
Jian Ting Xu ◽  
Chi Peng Liu
Keyword(s):  
Comparative Analysis ◽  
Prestressed Concrete ◽  
Three Dimensional ◽  
Stability Control ◽  
River Diversion ◽  
Finite Element Program ◽  
Dimensional Finite Element ◽  
Element Program ◽  
Stress And Deformation ◽  
Three Dimensional Finite Element

An aqueduct of larger-span prestressed concrete arch structure for river diversion project is located in coastal areas, and raises difficult questions on deformation and stability control of the construction process due to greater wind load and poor soil. Due to the limited width of bracket erection, this paper put forward five possible construction schemes, and does the comparative analysis using three-dimensional finite element program, and gets the economic and reasonable one. Finally conduct a pressure test after the bracket erection, and verify the analysis results using measured stress and deformation data.

scholarly journals Fatigue Behavior of Prestressed Concrete Beam for Straddle-Type Monorail Tracks

2018 ◽  
Vol 8 (7) ◽  
pp. 1136 ◽  
Author(s):  
Qianhui Pu ◽  
Hanyu Wang ◽  
Hongye Gou ◽  
Yi Bao ◽  
Meng Yan
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beam ◽  
Fatigue Behavior ◽  
Three Dimensional ◽  
Element Model ◽  
Transportation Systems ◽  
Traffic Load ◽  
Prestressed Concrete Beam ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Monorail transportation systems are widely built in medium and small cities, as well as hilly cities, because of their excellent performance. A prestressed concrete track beam is a key load-carrying structural component and guideway subjected to repeated traffic load. The fatigue behavior of the prestressed concrete beam is critical for the safety of the transportation system. This paper presents the results of an experimental study on the fatigue behavior of a prestressed concrete beam in terms of stiffness degradation and strain change. The displacement and rotation of the beam of concrete and reinforcement were examined, respectively. A three-dimensional finite element model was established to help understand the development of the mechanical behavior. No crack was observed throughout the test. Both concrete and bars behaved in their linear-elastic stage throughout the test, and the bond between them performed well.

The Characteristic of Prestressed Concrete Pier Seismic Crack

2014 ◽  
Vol 501-504 ◽  
pp. 1628-1632
Author(s):  
Hui Li Wang ◽  
Hong Wang ◽  
Si Feng Qin
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Prestressed Concrete ◽  
Three Dimensional ◽  
Element Model ◽  
Dimensional Finite Element ◽  
Tensile Zone ◽  
Three Dimensional Finite Element ◽  
Prestressed Reinforcement

Through three dimensional finite element analyzes, overall cast-in-place prestressed concrete pier seismic crack characteristic is researched. The separation formula finite element model is established by means of bilinear reinforce model and Kent-R.Park concretes model, without considering slip between concretes and. reinforce. It compares and analyzes the seismic crack characteristic between prestressed concrete pier and reinforcement concretes pier. The results show that the prestressed reinforcement can reduce the tensile zone of concrete, put off the appearance of cracks, improved the stiffness of pier, and reduced the top displacement.

A Parametric Study on Particulate Al-SiC Composite Bolted Joints

2006 ◽  
Author(s):  
Samir N. Shoukry ◽  
Jacky C. Prucz ◽  
Gergis W. William
Keyword(s):  
Load Transfer ◽  
Three Dimensional ◽  
Closed Form Solution ◽  
Lap Joints ◽  
Form Solution ◽  
Bolted Joints ◽  
Design Parameters ◽  
Dimensional Finite Element ◽  
Sliding Interfaces ◽  
Three Dimensional Finite Element

The main objective of this study is to predict theoretically the stress distributions around the holes in a bolted joint made of particulate metal matrix composite and to investigate the associated load transfer efficiencies both for a single and double lap bolted joints. A three-dimensional finite element parametric model has been developed to examine the effects of various design parameters on the structural performance of such joints. The main feature of this model is explicit modeling of the sliding interfaces between the connected plates and the washers, and those between the hole and the bolt. The model response showed an excellent agreement with a closed form solution as well as experimental data. The results indicated that unsymmetric configuration of single lap joints causes bending as the load is applied, which is opposite of the double lap joints. This research quantifies the relationship between the stress developed around the hole and washer diameter, tightening pressure, and clearance between the bolt and hole. It was also observed that variations in Young's modulus have no significant effect on the stress concentration around the hole.

scholarly journals Design Optimization of Concrete Aqueduct Structure considering Temperature Effects

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Liang-ze-nan Wang ◽  
Chao Su
Keyword(s):  
Construction Projects ◽  
Three Dimensional ◽  
Design Parameters ◽  
Reinforced Concrete Structure ◽  
Original Design ◽  
Engineering Construction ◽  
Field Coupling ◽  
Dimensional Finite Element ◽  
Water Conveyance ◽  
Three Dimensional Finite Element

An aqueduct is a water conveyance structure that enables channel flow across canals, valleys, depressions, roads, and other structures. The optimal structural selection of the aqueduct is particularly important to ensure engineering quality and optimize project investment. To optimize the design of an aqueduct structure, this study established a mathematical model based on the three-dimensional finite element method that considers the temperature field and structural stress field coupling among its design parameters. The model was used to optimize and design the main wall thickness and tie spacings of the aqueduct structure. The Caohe aqueduct was considered as an example for the proposed design. The influences of temperature-induced stress on the reinforced concrete structure of the aqueduct in winter and summer were investigated based on the actual engineering conditions of the structure, and the corresponding structural optimization was obtained. The results showed that the optimized aqueduct can offset temperature and structural stresses, thus reducing the amount of material required. The maximum generated stress was also lower than that of the original design. Furthermore, this study is expected to provide guidance for similar engineering construction projects.

scholarly journals Long-Term Deflection of Prestressed Concrete Bridge Considering Nonuniform Shrinkage and Crack Propagation by Equivalent Load Approach

2020 ◽  
Vol 10 (21) ◽  
pp. 7754
Author(s):  
Fiseha Nega Birhane ◽  
Sung-Il Kim ◽  
Seung Yup Jang
Keyword(s):  
Prestressed Concrete ◽  
Three Dimensional ◽  
Simplified Approach ◽  
Long Span Bridges ◽  
Long Span ◽  
Dimensional Finite Element ◽  
Current Design ◽  
Equivalent Load ◽  
Three Dimensional Finite Element

Long-span prestressed concrete (PSC) bridges often suffer excessive deflection during their service lives. The nonuniform shrinkage strains of concrete caused by uneven moisture distributions can induce significant additional deflections, when combined with the creep and cracking of the concrete. Current design practices usually overlook these factors, and the few proposed approaches to consider them are complex and computationally expensive. This study proposes a simplified approach for considering the effect of nonuniform shrinkage by using the equivalent load concept in combination with a nonlinear analysis of the creep and cracking using three-dimensional finite element models. The long-term deflections of short-, medium-, and long-span PSC bridges are calculated under the combined effects of creep, shrinkage, and cracking. The results show that the nonuniform shrinkage effect is significant in medium- to long-span bridges, and that the cracking of the concrete reduces the stiffness, thereby increasing the long-term deflection of the bridges (more severely so in combination with creep and shrinkage). The predicted long-term deflections reasonably agree with the measured data. Thus, the equivalent load approach is effective for calculating long-term deflections considering nonuniform shrinkage strains, without the complicated and expensive coupling of moisture transport and structural analyses.

scholarly journals Rehabilitation Effect Evaluation of CFRP-Lined Prestressed Concrete Cylinder Pipe under Combined Loads Using Numerical Simulation

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
He Hu ◽  
Fujun Niu ◽  
Tiesheng Dou ◽  
Heng Zhang
Keyword(s):  
Prestressed Concrete ◽  
Three Dimensional ◽  
Steel Cylinder ◽  
Concrete Core ◽  
Concrete Cylinder ◽  
Combined Loads ◽  
Reinforced Polymer ◽  
Dimensional Finite Element ◽  
Prestressed Concrete Cylinder Pipe ◽  
Three Dimensional Finite Element

Prestressed concrete cylinder pipe (PCCP) has been widely used for water transfer and transit projects. However, prestressing wire breaks may result in the rupture of pipes and cause catastrophes. Carbon fiber reinforced polymer (CFRP) liners adhered to the inner concrete core can provide an effective method of internal repair and strengthening of PCCP. To evaluate the rehabilitation effect of CFRP-lined PCCP under combined loads, two contrasting three-dimensional finite element models that investigated the visual cracking of concrete and the yielding of steel cylinders were developed. A conceptual zone was introduced to analyze the different states of the pipe during the phase of wire break. In particular, the complex CFRP-concrete bonded interface was simulated by a cohesive element layer with a bilinear traction-separation response. The results show that CFRP has a good rehabilitation effect on the inner concrete core and steel cylinder but only a slight effect on the outer concrete core, prestressing wire, or mortar. A one-hoop CFRP layer diminishes the area of a yielding steel cylinder of 4.72 m2. In addition, CFRP works more effectively along with an increase in the number of broken wires. This research can provide a basis for strengthening distressed PCCP pipelines.

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