Permit checking of overloaded customized transport vehicle based on serviceability limit state reliability of concrete bridges

2020 ◽  
pp. 136943322097245
Author(s):  
Yangguang Yuan ◽  
Wanshui Han ◽  
Xin Xu ◽  
Junfeng Wang ◽  
Jianpeng Sun
Keyword(s):  
Critical Load ◽  
Prestressed Concrete ◽  
Limit State ◽  
Concrete Bridges ◽  
Ultimate Limit State ◽  
Load Effect ◽  
Serviceability Limit State ◽  
Transport Vehicle ◽  
Checking Procedure ◽  
Effect Ratio

To increase the authorization efficiency of overloaded customized transport vehicle (CTV), a serviceability limit state (SLS) reliability based permit checking method for concrete bridges is proposed through the optimization towards critical load effect ratio. In this procedure, the SLS reliability of crack width and the SLS reliability of concrete stress in tensile region are analyzed for reinforced concrete (RC) and prestressed concrete (PC) structures, respectively. The durability requirements and a unified reliable level can be concentrated reflected by the optimized critical load effect ratio. The results show that it is unreasonable to take a uniform target reliability index for all routes in permit checking of CTV, a stricter authorization criterion should be adopted for a higher expected authorization frequency. For a specific route level, a fluctuant variation of critical load effect ratio can be found with the increasing of bridge span. By introducing an ultimate limit state (ULS) based safety checking procedure, it is found that the SLS based permit checking criterion is crucial and determinative for the authorization of CTV instead of the ULS.

scholarly journals Effect of Water Condensate on Corrosion of Wires in Ungrouted Ducts

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7765
Author(s):  
Radoslav Ponechal ◽  
Peter Koteš ◽  
Daniela Michálková ◽  
Jakub Kraľovanec ◽  
František Bahleda
Keyword(s):  
Prestressed Concrete ◽  
Steel Wire ◽  
Limit State ◽  
Concrete Structures ◽  
Concrete Bridges ◽  
The Other ◽  
Actual State ◽  
Ultimate Limit State ◽  
Cross Sectional ◽  
Prestressing Steel

In the case of existing prestressed concrete structures, information about the actual state of prestressing is an important basis for determining their load-carrying capacity, as well as remaining service lifetime. This is even more important in the case of existing prestressed concrete bridges, which are exposed to a more aggressive environment than the other prestressed concrete structures. The level of prestressing is affected and reduced by prestress losses at a given time. In calculating the internal forces and stresses, required for the assessment of the Ultimate Limit State and the Serviceability Limit State, it is necessary to know not only the prestressing level but also the cross-sectional area of the prestressing steel (wire, strand or cable), which can change in time due to corrosion. In practice, in the case of the pre-tensioned concrete members, it has often happened in the past that cable ducts have been grouted only partially, or not at all, due to poor grouting technology. Experts did not realize what this could cause in the future—the penetration of water with aggressive agents directly into the cable duct and consequently corrosion of the prestressing steel, which means not increased protection of the steel, but rather acceleration of degradation. On the other hand, in many cases, corrosion also occurs in ducts that are not grouted and no water has entered them. This paper deals with this phenomenon—the formation of corrosion of prestressing steel in cable ducts in ungrouted ducts due to moisture. This problem was investigated experimentally and numerically in the simulation program ESP-r. Experimental measurements and numerical simulations have shown that the water vapor condenses in the cable ducts, which can subsequently cause corrosion of the prestressing steel.

Safe Platooning Headways on Girder Bridges

2021 ◽  
pp. 036119812110363
Author(s):  
Bowen Yang ◽  
Joshua S. Steelman ◽  
Jay A. Puckett ◽  
Daniel G. Linzell
Keyword(s):  
Prestressed Concrete ◽  
Limit State ◽  
Live Load ◽  
Load Effect ◽  
Operational Strategies ◽  
Reliability Indices ◽  
Girder Bridges ◽  
Legal Limits ◽  
Weigh In Motion ◽  
Load And Resistance Factor

Truck platooning—digitally linking two or more trucks to travel in a closely spaced convoy—is an emerging technology with the potential to save fuel and reduce labor. A framework is described to determine how much a platoon permit load might be increased above Federal Bridge Formula B legal limits, given strict control over the load characteristics and operational tactics. Soon, platoons are expected to advance not only with respect to traffic operations but also in their ability to weigh and report axle weight and spacing, functioning as mobile weigh-in-motion vehicles. Consequently, platoon live load statistics (bias and coefficient of variation) can differ from code assumptions, and are perhaps controllable, which poses a significant opportunity with respect to operational strategies. A parametric study is presented that examined safe headways between platooning trucks, considering different girder spacings, span lengths, numbers of spans, types of structure, truck configurations, numbers of trucks, and adjacent lane loading scenarios. The Strength I limit state was evaluated for steel and prestressed concrete I-girder bridges optimally designed using load and resistance factor design. Reliability indices, β, were calculated for each load case based on Monte Carlo simulation. Summary headway guidance was developed and is presented here to illustrate potential safe operational strategies for varying truck weights and platoon live load effect uncertainties.

Analysis of serviceability limit state of GFRP prestressed concrete beams

2015 ◽  
Vol 134 ◽  
pp. 450-459 ◽  
Author(s):  
Mantas Atutis ◽  
Juozas Valivonis ◽  
Edgaras Atutis
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beams ◽  
Limit State ◽  
Serviceability Limit State

scholarly journals A Structural Analysis Of A Factory Hall With A Two-Story Office Building As A Precast And Prestressed Concrete Construction

2021 ◽  
Author(s):  
Olesja Befus
Keyword(s):  
Structural Analysis ◽  
Prestressed Concrete ◽  
Limit State ◽  
Steel Structure ◽  
Ultimate Limit State ◽  
Limit State Design ◽  
European Standards ◽  
Ultimate Limit State Design ◽  
Manual Calculation ◽  
Ultimate Limit

The objective of this thesis is to develop a precast and prestressed concrete design for a factory hall, which was initially planned as a steel structure. Furthermore, a structural analysis is conducted on several chosen structural elements according to the European Standards and the German Annexes respectively. The analysis is done both by manual calculation and software calculation for comparison and includes the ultimate limit state design, the serviceability limit state design and the design for the state of transportation and assembly of the precast members. Lastly, to illustrate the results of the analysis, an overview drawing with the new concrete design as well as formwork and reinforcement drawings for each of the analyzed structural members are developed.

scholarly journals Service Life Prediction of Precast Concrete Structures Exposed to Chloride Environment

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Dawei Zhang ◽  
Yu Zeng ◽  
Mingshan Fang ◽  
Weiliang Jin
Keyword(s):  
Shear Failure ◽  
Precast Concrete ◽  
Probability Model ◽  
Limit State ◽  
Concrete Structures ◽  
Seismic Load ◽  
Ultimate Limit State ◽  
Interface Shear ◽  
Serviceability Limit State ◽  
Corrosion Initiation

Chloride-induced corrosion is widely accepted as one of the primary causes of premature deterioration for concrete structures in marine or deicing salt environment. For precast concrete (PC) structures, such durability problems may even be severer because defects in joint areas, e.g., cracks caused by grout shrinkage and improper construction, can accelerate chloride ion transportation process and may cause the interface shear failure when subjected to seismic load. By applying the path probability model (PPM) and reliability theory, a probabilistic framework was proposed to predict three limit states of PC structures, including corrosion initiation, serviceability limit state, and ultimate limit state. Using Monte Carlo simulation, a beam-to-column joint was further analyzed to illustrate the differences between PC structures and those cast in situ. The analysis indicates that corrosion initiation and serviceability limit state are sensitive to chloride diffusivity at connection area, and the higher pitting factor can significantly influence the bearing capacities of PC structures.

Analysis of the Superstructure of South-to-North Water Diversion Bridge

2012 ◽  
Vol 178-181 ◽  
pp. 2125-2130
Author(s):  
Ming Hong Li ◽  
Yi Li Wang ◽  
Shui Wan
Keyword(s):  
Prestressed Concrete ◽  
Limit State ◽  
Vertical Shear ◽  
Water Diversion ◽  
Ultimate Limit State ◽  
North Water ◽  
Corrugated Steel Web ◽  
Girder Bridge ◽  
Standard Limit ◽  
Ultimate Limit

Based on the South-to-North Water Diversion Bridge (70m+120m+70m prestressed concrete composite box-girder bridge with corrugated steel webs), structural static analysis of the bridge’s superstructure was taken out by finite element method, which were checked with the existing regulatory requirements. The result indicates that the carrying capacity in the ultimate limit state meet the requirement of the standard, the vertical shear stress of corrugated steel web satisfies the standard limit and the thickness of corrugated steel web satisfies the request, but the safety factor is not high.

scholarly journals Automation of the evaluation of bonded and unbonded prestressed concrete beams, according to brazilian and french code specifications

2013 ◽  
Vol 6 (1) ◽  
pp. 13-54
Author(s):  
P. M. Lazzari ◽  
A. Campos Filho ◽  
F. P. S. L. Gastal ◽  
R. A. Barbieri ◽  
R. C. Schwingel
Keyword(s):  
Prestressed Concrete ◽  
Geometric Nonlinearity ◽  
Computational Algorithm ◽  
Concrete Beams ◽  
Limit State ◽  
Ultimate Limit State ◽  
Flexural Members ◽  
Design Procedures ◽  
Planar Frames ◽  
Ultimate Limit

This paper presents a suggestion for the automation of the design procedures of bonded and unbonded prestressed concrete flexural members, according to the Brazilian (NBR 6118:2007) and French (Règles BPEL 91) norm specifications. Prestressing of concrete structures has been increasingly used, mainly due to its building advantages, as well as allowing reducing crack incidence and element dimensions by the use of more resistant materials. Structure is analyzed by a numerical model that employs a hybrid type finite element for planar frames, considering geometric nonlinearity, cyclic loading and composite construction. The computational algorithm implemented considers full, partial and limited prestressing situations, evaluating in each case decompression limit state, limit state of cracking, ultimate limit state and final prestressing state. Finally, two examples comparing design situations according to the Brazilian and French norms are presented.

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