scholarly journals A Combined Experimental–Numerical Framework for Assessing the Load-Bearing Capacity of Existing PC Bridge Decks Accounting for Corrosion of Prestressing Strands

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4914
Author(s):  
Dario De Domenico ◽  
Davide Messina ◽  
Antonino Recupero
Keyword(s):  
Bearing Capacity ◽  
Bridge Decks ◽  
Fe Model ◽  
Load Bearing Capacity ◽  
Priority List ◽  
Load Bearing ◽  
Effective Manner ◽  
Bridge Structures ◽  
Prestressing Strands

Bridges constitute important elements of the transportation network. A vast part of the Italian existing infrastructural system dates to around 60 years ago, which implies that the related bridge structures were constructed according to past design guidelines and underwent a probable state of material deterioration (e.g., steel corrosion, concrete degradation), especially in those cases in which proper maintenance plans have not been periodically performed over the structural lifetime. Consequently, elaborating rapid yet effective safety assessment strategies for existing bridge structures represents a topical research line. This contribution presents a systematic experimental–numerical approach for assessing the load-bearing capacity of existing prestressed concrete (PC) bridge decks. This methodology is applied to the Longano PC viaduct (southern Italy) as a case study. Initially, natural frequencies and mode shapes of the bridge deck are experimentally identified from vibration data collected in situ through Operational Modal Analysis (OMA), based on which a numerical finite element (FE) model is developed and calibrated. In situ static load tests are then carried out to investigate the static deflections under maximum allowed serviceability loads, which are compared to values provided by the FE model for further validation. Since prestressing strands appear corroded in some portions of the main girders, numerical static nonlinear analysis with a concentrated plasticity approach is finally conducted to quantify the effects of various corrosion scenarios on the resulting load-bearing capacity of the bridge at ultimate limit states. The proposed methodology, encompassing both serviceability and ultimate conditions, can be used to identify critical parts of a large infrastructure network prior to performing widespread and expensive material test campaigns, to gain preliminary insight on the structural health of existing bridges and to plan a priority list of possible repairing actions in a reasonable, safe, and costly effective manner.

scholarly journals In situ Determination of Load Bearing Capacity of Soils on the Airfields

2015 ◽  
Vol 15 ◽  
pp. 11-18 ◽  
Author(s):  
Martin Decký ◽  
Eva Remišová ◽  
Martin Mečár ◽  
Ladislav Bartuška ◽  
Ján Lizbetin ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Load Bearing Capacity ◽  
Load Bearing

scholarly journals The Influence of Improved Strength Grading In Situ on Modelling Timber Strength Properties

Buildings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 30
Author(s):  
Maria Loebjinski ◽  
Wolfgang Rug ◽  
Hartmut Pasternak
Keyword(s):  
Bearing Capacity ◽  
Strength Properties ◽  
Material Strength ◽  
Timber Species ◽  
Load Bearing Capacity ◽  
Visual Evaluation ◽  
Load Bearing ◽  
Existing Structures ◽  
Ultrasonic Time

The management and preservation of structures in our built environment are central and challenging tasks for practicing engineers. Within the CEN member states (European Committee for Standardization), the so-called Eurocodes form the basis of the design and verification of the load-bearing capacity of structures. Current Eurocodes do not contain special recommendations for existing structures, meaning that the principles for new structures are applied. This can lead to an incorrect estimation of the load-bearing capacity within the semi-probabilistic safety concept. A central task within the investigation and evaluation of existing structures is the strength grading of the material in situ using non-/semi-destructive technical devices. Studies show the potential of the ultrasonic time-of-flight measurement in combination with visual evaluation for an improved grading. The information on the material from an improved grading technique can be used to update the material parameters as a target variable using a measured reference variable. In this contribution, test data from a partner project (spruce, pine, and oak) are analyzed, applying the stochastic grading model of Pöhlmann and Rackwitz. It can be shown that different grading techniques influence the updated distribution function of the material strength within the grade. The results depend on the timber species. Perspectives to develop updated models dependent on the knowledge available are shown and discussed.

In-situ formed carbon based composite tribo-film with ultra-high load bearing capacity

2020 ◽  
Vol 152 ◽  
pp. 106577
Author(s):  
Jiasheng Hu ◽  
Yujuan Zhang ◽  
Guangbin Yang ◽  
Chuanping Gao ◽  
Ningning Song ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
High Load ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Carbon Based

scholarly journals Justification of the development and application of express assessment programs for road bridges when heavy vehicles pass through them

2021 ◽  
Vol 17 (4) ◽  
pp. 315-323
Author(s):  
Evgeny A. Lugovtsev
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Rapid Assessment ◽  
Technical Condition ◽  
Heavy Vehicles ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Bridge Structures ◽  
Pass Through ◽  
State Registration

The theoretical prerequisites for justifying the development of two rapid assessment programs for road bridges to quickly determine the possibility of passing heavy vehicles on road bridge structures of a split and non-split system, made of wood, metal, steel-reinforced concrete, reinforced concrete with stressed and non-stressed reinforcement, according to the measured angle of rotation of their support sections, taking into account their actual operational condition, are presented. The programs implemented an experimental and analytical method for assessing the technical condition of road bridges for reliability. The features, conditions of application, positive and negative aspects of each version of the program are revealed. The creation of two variants of programs is due to, on the one hand, the need to ensure the safety of the driver of the vehicle and the bridge structure, and on the other hand, the need to guarantee the possibility of safe passage of heavy vehicles, both under the conditions of the load-bearing capacity of superstructures and the load-bearing capacity of road bridge supports, taking into account their actual operational condition. Both developed calculation programs were implemented by using a personal computer and certificates of state registration of computer programs were obtained. The developed programs will be used as part of the modernized IR-AM measuring complex.

Research of Gfrp Shell Confined Concrete Columns Behavior Under Axial Compression

2021 ◽  
pp. 92-102
Author(s):  
В. А. Шендрик
Keyword(s):  
Bearing Capacity ◽  
Concrete Columns ◽  
Outer Shell ◽  
Experimental Investigations ◽  
Plastic Shell ◽  
Load Bearing Capacity ◽  
Concrete Core ◽  
Load Bearing ◽  
Glass Fiber Reinforced Plastic ◽  
Bridge Structures

Постановка задачи. Исследуется влияние внешних композитных (стеклопластиковых) оболочек, которые имеют различные физико-механические свойства в продольном и поперечном направлениях, на увеличение прочности находящегося внутри оболочек бетонного ядра. Результаты. Представлены результаты экспериментальных исследований несущей способности, позволяющие оценить эффективность применения внешней цельной стеклопластиковой оболочки в качестве усиления бетонной стойки. Результаты исследования позволили определить основной фактор, значительно влияющий на несущую способность гибридной стойки с композитной оболочкой. Выводы. Получен более высокий показатель несущей способности гибридных стоек в сравнении с традиционно применяемыми в мостостроении стойками. Тем самым доказана возможность применения в опорах мостовых сооружений гибридных по материалу стоек, состоящих из внешней цельной стеклопластиковой оболочки и внутреннего бетонного ядра, которые ранее не применялись в мостовых конструкциях. Statement of the problem. The influence of external GFRP (glass-fiber-reinforced-plastic) shell, with different physicomechanical longitudinal and transverse properties on increasing the strength of the concrete core is investigated. Results. The article presents the results of experimental investigations of the load-bearing capacity to evaluate the effectiveness of using a solid fiberglass outer shell as a reinforcement of a concrete column. The results of the study has allowed us to establish the major factor that significantly affects the load-bearing capacity of a hybrid column with a composite shell. Conclusions. A higher load-bearing capacity of hybrid supports in comparison with the concrete columns traditionally used in bridge construction. This proves the possibility of using hybrid columns in the supports of bridge structures consisting of concrete core confined solid fiberglass outer shell that were not previously used in bridge structures.

Sign in / Sign up

Export Citation Format

Share Document