Evaluation of the Load-Bearing Capacity of Timber Members in Existing Structures Based on Information from a Qualified Investigation In Situ Within a Stepwise Procedure

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.

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Assessment of Load-Bearing Capacity of Bridges

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.259.113 ◽

2017 ◽

Vol 259 ◽

pp. 113-118 ◽

Cited By ~ 1

Author(s):

Jaroslav Navrátil ◽

Michal Drahorád ◽

Petr Ševčík

Keyword(s):

Bearing Capacity ◽

Prestressed Concrete ◽

Iterative Solution ◽

Concrete Bridges ◽

Load Bearing Capacity ◽

Load Bearing ◽

Prestressed Concrete Bridges ◽

Existing Structures ◽

Non Linear

The paper aims to the determination of load-bearing capacity of reinforced/prestressed concrete bridges subjected to the combination of all components of internal forces according to Eurocode standards for assessment of existing structures. Undoubtedly bridge load rating is laborious hand-iterative process, especially when it comes to reinforced and/or prestressed concrete bridges. The engineer can spend days and weeks trials and errors in the estimation of bridge load-carrying capacity. The problem lies in the determination of load-bearing capacity of cross-section subjected to the combination of normal and shear forces, bending and torsional moments. Due to the different effects of permanent and variable loads and the non-linear behavior of structural materials, the problem becomes non-linear and its solution requires the use of suitable iterative method. Optimized iterative solution was implemented into IDEA StatiCa software and the results are presented in this paper.

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Correlating in-situ process monitoring data with the reduction in load bearing capacity of selective laser melted Ti–6Al–4V porous biomaterials

Journal of the Mechanical Behavior of Biomedical Materials ◽

10.1016/j.jmbbm.2020.103723 ◽

2020 ◽

Vol 106 ◽

pp. 103723

Author(s):

Darragh S. Egan ◽

Denis P. Dowling

Keyword(s):

Bearing Capacity ◽

Process Monitoring ◽

Monitoring Data ◽

Load Bearing Capacity ◽

Load Bearing ◽

Porous Biomaterials

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

Procedia Earth and Planetary Science ◽

10.1016/j.proeps.2015.08.004 ◽

2015 ◽

Vol 15 ◽

pp. 11-18 ◽

Cited By ~ 8

Author(s):

Martin Decký ◽

Eva Remišová ◽

Martin Mečár ◽

Ladislav Bartuška ◽

Ján Lizbetin ◽

...

Keyword(s):

Bearing Capacity ◽

Load Bearing Capacity ◽

Load Bearing

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Research on cast in-situ pile load bearing capacity characteristics in hand made excavation

2011 International Conference on Consumer Electronics, Communications and Networks (CECNet) ◽

10.1109/cecnet.2011.5769429 ◽

2011 ◽

Author(s):

Xiaoming Dong ◽

Yongli Xie

Keyword(s):

Bearing Capacity ◽

Load Bearing Capacity ◽

Load Bearing

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The Influence of CFRP Sheets on the Load-Bearing Capacity of the Glued Laminated Timber Beams under Bending Test

Materials ◽

10.3390/ma14144019 ◽

2021 ◽

Vol 14 (14) ◽

pp. 4019

Author(s):

Klaudia Śliwa-Wieczorek ◽

Krzysztof Adam Ostrowski ◽

Justyna Jaskowska-Lemańska ◽

Anna Karolak

Keyword(s):

Bearing Capacity ◽

Standard Procedure ◽

Bending Test ◽

Load Bearing Capacity ◽

Load Bearing ◽

Existing Structures ◽

Reinforced Beams ◽

Glued Laminated Timber ◽

Before And After ◽

Timber Beams

Composite materials are increasingly used to strengthen existing structures or new load-bearing elements, also made of timber. In this paper, the effect of the number of layers of Carbon Fiber Reinforced Polymer (CFRP) on the load-bearing capacity and stiffness of Glued Laminated Timber beams was determined. Experimental research was performed on 32 elements—a series of eight unreinforced beams, and three series of eight reinforced beams: with one, three and five layers of laminate each. The beams with a cross-section of 38 mm × 80 mm and a length of 750 mm were subjected to the four-point bending test according to standard procedure. For each series, destructive force, deflection, mode of failure, and equivalent stiffness were determined. In addition, for the selected samples, X-ray computed tomography was performed before and after their destruction to define the quality of the interface between wood and composite. The results of the conducted tests and analyses showed that there was no clear relationship between the number of reinforcement layers and the load-bearing capacity of the beams and their stiffness. Unreinforced beams failed due to tension, while reinforced CFRP beams failed due to shear. Despite this, a higher energy of failure of composite-reinforced elements was demonstrated in relation to the reference beams.

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Investigation of the load-bearing behavior of composite joints in cross-section supplements for concrete structures

10.2749/ghent.2021.1872 ◽

2021 ◽

Author(s):

Christian Knorrek ◽

Sven Bosbach ◽

Josef Hegger

Keyword(s):

Bearing Capacity ◽

Structural Concrete ◽

Load Bearing Capacity ◽

Research Project ◽

Cross Sectional ◽

Ongoing Research ◽

Load Bearing ◽

Existing Structures ◽

Composite Joint ◽

Bearing Behavior

<p>The strengthening with cross-sectional supplements made of reinforced concrete is already of great importance in building, bridge, and industrial constructions and will be further developed in the future because of the increasing demands on existing structures [1]- [3].</p><p>As part of an ongoing research project at the Institute of Structural Concrete at RWTH Aachen University, funded by the German Federation of Industrial Research Associations (AiF), a correlation between the method of surface treatment of the old concrete, the measured roughness, the type of concrete supplementation, and the load-bearing capacity of the composite joint has to be derived by means of new systematic test series. As a result, a database, and a possible practical guide on the load-bearing capacity of different combinations of old concretes, surface treatments, supplementary concrete layers, and bonding conditions will be developed. This paper will present the initial findings from this research project.</p>

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

Materials ◽

10.3390/ma14174914 ◽

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.

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