Preliminary design of standard CPCI prestressed bridge girders by linear programming

1985 ◽  
Vol 12 (1) ◽  
pp. 213-225 ◽  
Author(s):  
Sami M. Fereig
Keyword(s):  
Linear Programming ◽  
Prestressed Concrete ◽  
Programming Model ◽  
Concrete Strength ◽  
Bending Moment ◽  
Highway Bridges ◽  
Concrete Bridges ◽  
Preliminary Design ◽  
Concrete Girders ◽  
Prestressing Force

The design of prestressed concrete bridges using standard CPCI (Canadian Prestressed Concrete Institute) girders is generally done by trial and error, requiring extensive computation. This study will use a linear programming mathematical model to establish preliminary design charts for such cases and to obtain the required prestressing force after losses for a given CPCI bridge interior girder with different spans and spacings. The bridge is designed to carry the MS200-77 loading, and the design conforms with the Canadian Standards Association CAN3-S6-M79 for design of highway bridges. The bridge considered is single-span, with a cast in situ concrete deck acting compositely with the prestressed girders under live load. The linear programming model is also used to determine the design criteria that will control the design for the cases investigated, and to perform the parametric study to evaluate the effect of variations in deck thickness, girder concrete strength, and prestressing losses on the value of the required prestressing force. Key words: bending moment, concrete, girders, highway bridges, linear programming, load, prestressing, span.

Preliminary design of standard prestressed bridges using box girders or hollow slabs

1990 ◽  
Vol 17 (2) ◽  
pp. 262-270 ◽  
Author(s):  
Sami M. Fereig ◽  
Kenneth N. Smith
Keyword(s):  
Linear Programming ◽  
Programming Model ◽  
Concrete Strength ◽  
Highway Bridges ◽  
Preliminary Design ◽  
Box Girders ◽  
Prestressing Force ◽  
Prestressed Girders ◽  
Girder Bridge

This study uses a linear programming mathematical model to establish preliminary design charts for prestressed bridges using box girders or hollow slabs, giving the required prestressing force after losses for an interior girder for various spans and spacings. The structure is designed to carry the MS200-77 loading, and the design conforms with the Canadian Standards Association Standard CAN3-S6-M78 for design of highway bridges. The bridge considered is single-span, with a cast in situ concrete deck acting compositely with the prestressed girders under live load. The linear programming model is also used to determine the design criteria that will control the designs for the cases investigated, and to perform the parametric study to evaluate the effect of variations in deck thickness, girder concrete strength, and prestressing losses on the value of the required prestressing force. Key words: box girder, bridge, design, hollow slab, linear programming, prestressing.

scholarly journals Long-term Deflections in Balanced Cantilever Prestressed Concrete Bridges

2009 ◽  
Vol 4 (1) ◽  
pp. 22
Author(s):  
Eltayeb Hassan Onsa ◽  
Elsafi Mohamed Adam ◽  
Abdalla Khogali Ahmed ◽  
Mohamed Elmontasir Elbagir
Keyword(s):  
Prestressed Concrete ◽  
Concrete Bridges ◽  
Live Load ◽  
Prestressed Concrete Bridges ◽  
Prestressing Force ◽  
Load Tests ◽  
The Moment ◽  
Aashto Lrfd ◽  
Made In

Long-term deflections in balanced cantilever prestressed concrete bridges are reviewed. Burri and Shambat Bridges are taken as cases study to calculate long-term deflection. The two bridges were constructed at Khartoum State in the years 1972 and 1962, respectively. Due to the shortage of the basic data regarding the two bridges the AASHTO-LRFD is used to estimate and calculate the missing data in the two bridges. The Moment Area method is used to calculate the long-term deflections due to the dead load, live load and prestressing force. The calculated long-term deflections are compared with measured live load deflections obtained from load tests made by a Chinese contractor requested to evaluate the two bridges. Remarkable differences between theoretical and measured deflection at the end of cantilevers are encountered. The differences are probably due to the basic assumptions made in the formulations of deflection calculations. Some adjustments in the long-term deflection formulae are suggested to bring the calculated deflections in compatibility with measured ones.

scholarly journals Moment redistribution in continuous prestressed concrete box girder with corrugated steel webs

2019 ◽  
Author(s):  
Jin-Sheng Du ◽  
Pui-Lam Ng ◽  
Xiang Ma ◽  
Jian Wang
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Prestressed Concrete ◽  
Concrete Strength ◽  
Bending Moment ◽  
Element Model ◽  
Box Girder ◽  
Moment Redistribution ◽  
Calculation Results ◽  
The Moment

A fibre-finite-element model of continuous prestressed concrete (PC) composite box girder with corrugated steel webs is established with force-based elements using OpenSees. After the model is validated with existing experimental data, the effects of reinforcement index in upper and lower flanges, effective prestress and concrete strength on the moment redistribution behaviour is analysed. It is shown that increasing the reinforcement index in lower flange or effective prestress can increase the amount of bending moment redistribution, whereas increasing the concrete strength or reinforcement index in upper flange can decrease the amount of bending moment redistribution. By inspecting the sensitivity of parameters, it is found that the reinforcement index in lower flange has the most significant influence on the moment redistribution, followed by the concrete strength and then by the effective prestress, while the reinforcement index in upper flange has only little impact on the moment redistribution. The calculation results are compared with the existing formulas. Finally, a moment redistribution formula is proposed for continuous PC box girder with corrugated steel webs.

scholarly journals Influence of Cracking on Effects of Restrained Deformations in a Post-tensioned Concrete Bridge

2018 ◽  
Vol 59 (1) ◽  
pp. 95-110
Author(s):  
Kimmo Jalonen ◽  
Joonas Tulonen ◽  
Anssi Laaksonen
Keyword(s):  
Bending Moment ◽  
Bending Stiffness ◽  
Concrete Bridges ◽  
Concrete Bridge ◽  
Linear Temperature ◽  
Prestressing Force ◽  
Bridge Superstructure ◽  
The Difference ◽  
General Force ◽  
Post Tensioned

Abstract Imposed and restrained deformations cause stresses in continuous concrete bridges, and in analyses of the superstructure these stresses are usually reduced to some degree due to creep and cracking of concrete. This study examines cracking and redistribution of stresses in a bridge superstructure under the loads and load combinations used in the original bridge design. The subject of this study is a three-span post-tensioned continuous concrete cantilever beam bridge. The bridge was analysed with non-linear calculation utilising the general force method and moment-curvature relationships. The analysis yielded the bending stiffness of the post-tensioned bridge superstructure as a function of bridge length under different loads. It was discovered that the secondary moment from prestressing force increased as the bending stiffness of the central span decreased due to cracking under external loads, which is not normally considered in design. The bending moment effects of linear temperature difference and support settlement decreased as expected as the superstructure bending stiffness decreased. The analysis provided new information on the effects of secondary moment from the prestressing force and on the difference between the cracked state and the linear elastic analysis of the concrete bridge superstructure.

Study on Evaluation Procedures for Prestressed Concrete Bridges Damaged by Salt Attack with Severe Corrosion of PC Cables

2019 ◽  
Author(s):  
Koji Osada ◽  
Kiyohisa Ono ◽  
Masafumi Hattori ◽  
Shoji Nojima
Keyword(s):  
Prestressed Concrete ◽  
Fem Analysis ◽  
Highway Bridges ◽  
Concrete Bridges ◽  
Experimental Results ◽  
Nonlinear Fem ◽  
Prestressed Concrete Bridges ◽  
Design Formula ◽  
Evaluation Procedures

<p>Considering the management of highway bridges in service under severe conditions for more than 100 years, evaluation of safety is indispensable. By adopting design formulae, it is possible to evaluate the safety quantitatively without complicated processes. However, to adopt a formula from the design, the structure needs to satisfy the Navier hypothesis and other requirements. For these reasons, the authors carried out an examination of evaluation procedures to define the limit deterioration state of PC structures for adopting a design formula. By comparing evaluation results of a design formula and experimental results of an actual PC beam removed from service, and also nonlinear FEM analysis results, the study shows the limit deterioration state of PC structures for adopting a design formula for the evaluation of safety.</p>

scholarly journals Parameters Analysis for Bending Properties of Externally Prestressed Concrete Beam with Corrugated Steel Webs

2018 ◽  
Vol 186 ◽  
pp. 02006
Author(s):  
Qiang Xu ◽  
Jianyong Song ◽  
Jianxiang Feng ◽  
Jinsheng Du
Keyword(s):  
Cross Section ◽  
Prestressed Concrete ◽  
Composite Beam ◽  
Concrete Beam ◽  
Concrete Strength ◽  
Bending Moment ◽  
Bending Performance ◽  
Prestressed Concrete Beam ◽  
External Tendons ◽  
Bending Process

Based on the bending moment-curvature method, a calculation program for the whole bending process of externally prestressed concrete beam with corrugated steel webs is compiled and parametric analysis is conducted. Considering the nonlinearity of material, this procedure can calculate the whole bending process of externally prestressed composite beam with corrugated steel webs under different load, cross section, and external tendons profiles and output the cross section strain of concrete and ordinary reinforcements, stress increment of external prestressing tendons and mid-span deflection. The results show that the tension steel area has the greatest impact on the bending performance of simply supported externally prestressed composite beam with corrugated steel webs; The second is concrete strength and effective external prestress; The compression steel area has limited impact on the bending performance of such beams. The results can provide a reference for design of the beam.

scholarly journals Effects of Blast Loading on Prestressed Girder Bridges

2012 ◽  
Vol 19 (1) ◽  
pp. 1-18 ◽  
Author(s):  
William F. Cofer ◽  
Debra S. Matthews ◽  
David I. McLean
Keyword(s):  
Prestressed Concrete ◽  
Critical Role ◽  
Blast Loading ◽  
Highway Bridges ◽  
Element Model ◽  
Concrete Bridges ◽  
September 11Th ◽  
Girder Bridges ◽  
Bridge Model ◽  
Precast Prestressed Concrete

Since the events of September 11th, increased attention has been given to the effects of blast loading on structures. Bridges are especially important due to their potentially critical role in the economy and for emergency response. Prestressed concrete highway bridges are very common, representing 11 percent of state bridges nationwide. Yet, very little is known about how prestressed concrete bridges respond to blast loading.A finite element model of a precast, prestressed concrete girder was created and validated with two experimental blast tests. It was found that for an explosive event above or below the girder, numerical and empirical results were consistent.The girder model was expanded to a four-girder, simple-span bridge model. Three different scenarios were examined at the midspan of the bridge: a blast between two girders above the deck, a blast centered on a girder above the deck, and a blast beneath the deck. The two load cases from above resulted in highly localized damage with the possibility for other sections of the bridge to be immediately reopened after the event. Results for the load case from below indicate that the slab will be heavily damaged but the girders will remain intact.

scholarly journals Analysis and Design of Fly Over

2021 ◽  
Vol 1197 (1) ◽  
pp. 012048
Author(s):  
G Harsha Vardhan ◽  
A. Venkateswara Rao
Keyword(s):  
Prestressed Concrete ◽  
Bending Moment ◽  
Concrete Bridges ◽  
Background Information ◽  
Infrastructure Development ◽  
Analysis And Design ◽  
Aesthetic Appearance ◽  
Bridge Structures ◽  
Grillage Analysis ◽  
Exterior Girder

Abstract Bridges remain the key components in any road network for infrastructure development. For use of prestress girder type bridges become popular for the reason that of its stability, economy, serviceability, aesthetic appearance and structural competence. The grillage analysis method for analysing bridge structures has been in use. In this work, an attempt is made to provide advise on grillage idealisation of the structure, as well as background information. The mesh layout is explained in detail. Analysis of proposal of prestressed concrete bridges are carried out using relevant IRC codes and IS codes. The bridge deck is analysed by grillage analysis. The present work was accepted out to exterior girder of span 28.2 m, width 12.5 m and with thickness of slab as 0.225m. The members are designed for maximum shear forces & bending moment. Losses of stress due to friction, anchorage slip, elastic shortening concrete & relaxation of stress in steel are also considered. The analysis has analysed by STAAD PRO software

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