scholarly journals The Influence of Dowel-Pin Connections on the Seismic Fragility Assessment of RC Precast Industrial Buildings

2017 ◽  
Vol 11 (1) ◽  
pp. 1138-1157 ◽  
Author(s):  
Pardo Antonio Mezzapelle ◽  
Agnese Scalbi ◽  
Francesco Clementi ◽  
Stefano Lenci
Keyword(s):  
Seismic Vulnerability ◽  
Structural Safety ◽  
Seismic Fragility ◽  
Load Carrying Capacity ◽  
Structural Elements ◽  
The Past ◽  
Industrial Buildings ◽  
Load Carrying ◽  
Annual Frequency ◽  
The Mean

Background:Recent major earthquakes in the centre of the Italy, between August and October 2016, have reaffirmed the seismic vulnerability of precast industrial buildings with a lot of collapse recorded. This is typical due to the past Italian building practices, where structural deficiencies are mainly related to the capacity to transfer horizontal forces between primary structural elements.Objectives and Methods:In these types of structures, a key role is played by the dowel pin connections which allow to transfer lateral horizontal forces from the beam to the column, without losing load carrying capacity. For this reason, in this work, the assessment of the seismic fragility of single-story reinforced concrete precast building located not far from the epicentres of the two aforementioned earthquakes was done.Results and Conclusion:The seismic risk was evaluated in terms of annual frequency of exceedance for three performance levels provided by the European and Italian seismic codes, considering the mean hazard curves for the site. The comparison between the fragility of different structural models shows the importance in the choice of the column-beam connection modelling to obtain reliable results on the structural safety assessment.

scholarly journals Starred angles supporting secondary trusses

1991 ◽  
Vol 18 (1) ◽  
pp. 118-129
Author(s):  
Murray C. Temple ◽  
Kenneth Hon-Wa Mok
Keyword(s):  
Cross Section ◽  
Carrying Capacity ◽  
Slenderness Ratio ◽  
The Other ◽  
Load Carrying Capacity ◽  
Industrial Buildings ◽  
Compression Members ◽  
Load Carrying ◽  
Structural Connections ◽  
Open Nature

In some large industrial buildings, it is common to span large areas by using primary trusses in one direction and secondary trusses in the other. The secondary trusses frame into the vertical web members in the primary trusses. Starred angles are frequently used as the vertical web members in the primary trusses because of their symmetrical cross section and the ease with which the connections can be made. These starred angles are usually designed as axially loaded members, but the open nature of the cross section and the fact that the secondary truss frames into one of the angles has raised some doubts about this loading assumption. As a result of this concern, an experimental research program was undertaken to investigate the behaviour and strength of starred angle web members supporting secondary trusses. The results obtained indicate that these starred angle compression members are not concentrically loaded, as the stress distribution across the angles is not uniform. It was found that if the slenderness ratio is modified in accordance with the requirements of ASCE Manual 52, the load-carrying capacity of the starred angles supporting secondary trusses can be determined using Clause 13.3.1 of CAN3-S16.1-M84. Key words: angles (starred), buckling, columns (structural), connections, trusses.

Introduction of Regional Confined Concrete

2013 ◽  
Vol 671-674 ◽  
pp. 697-703 ◽  
Author(s):  
Xin Ming Cao ◽  
Xian Wu Huang ◽  
Zhi Gang Mo ◽  
Hong Yuan Tian
Keyword(s):  
Confined Concrete ◽  
Load Carrying Capacity ◽  
Axial Loads ◽  
The Past ◽  
Short Columns ◽  
Load Carrying ◽  
Strain Relationship ◽  
Relationship Of ◽  
Experimental Researches ◽  
Concrete Elements

Based on the research of normal confined concrete (NCC), regional confined concrete (RCC) was proposed years ago by authors. With the introduction of regional confinement concept, different mechanical properties, failure mode and energy dispatching property developed in the regional confined concrete elements. Experimental researches have been carried out during the past years on the elements under various loads, including beams under moments, short beams under shears, short columns under axial loads, middle long columns under eccentric loads, middle long columns under axial loads and columns under cycling loads. Experimental results indicated that RCC elements are more ductile, have better load carrying capacity and larger energy dispatch capacity than that of NCC elements. Stress-strain relationship of RCC, integrated confinement factor and some computation expressions for elements under various loads are proposed. Pilot projects have been conducted and regional confined concrete structures are ready for service.

Effect of Tow Sheet Composite Wrap Architecture on Strengthening of Concrete Due to Confinement: I—Experimental Studies

1995 ◽  
Vol 14 (9) ◽  
pp. 1008-1030 ◽  
Author(s):  
Ian Howie ◽  
Vistasp M. Karbhari
Keyword(s):  
Concrete Strength ◽  
Experimental Studies ◽  
Load Carrying Capacity ◽  
Structural Elements ◽  
New Techniques ◽  
Column Type ◽  
Load Carrying ◽  
Concrete Shell ◽  
Original Construction ◽  
Stub Columns

Worldwide there is a need for the renewal of infrastructure because of age, deterioration, misuse, lack of timely repair and maintenance, use of improper materials and/or techniques in the original construction, and even changing needs. Notwithstanding the need for retrofit and repair methods for column-type structural elements, there is also a need for new techniques that would increase the confining action of concrete, as well as enhance the load-carrying capacity and ductility of such structures from a strengthening, rather than a seismic, viewpoint. This study investigates the use of carbon-fiber-reinforced jackets applied to concrete stub columns through the use of tow-sheet-type fabric forms. The primary emphasis is on the investigation of orientation and thickness effects of the composite wraps on the load-carrying efficiency and enhanced ductility of the new structural elements. It was seen that the predominant use of hoop reinforcement provides significant enhancement in concrete strength through confining action and also offers the potential for fabrication of concrete shell-type elements that would enable reinforcing action without the use of steel and the attending problems of corrosion.

scholarly journals FLEXURAL LOAD AND DEFLECTION BEHAVIOR OF STRUCTURAL BAMBOO FILLED WITH CEMENT MORTAR

2021 ◽  
Vol 83 (4) ◽  
pp. 31-39
Author(s):  
Gathot Heri Sudibyo ◽  
Nor Intang Setyo Hermanto ◽  
Hsuan-Teh Hu ◽  
Yanuar Haryanto ◽  
Laurencius Nugroho ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Carrying Capacity ◽  
Cement Mortar ◽  
Natural Material ◽  
Load Carrying Capacity ◽  
Structural Elements ◽  
Load Bearing ◽  
Four Point Bending ◽  
Bamboo Nodes ◽  
Load Carrying

Bamboo has been significantly and rapidly used to build temporal and permanent structures since time immemorial. However, this renewable natural material has a low bearing capacity, limiting its application to structures under light loads. Therefore, this research was carried out to determine an innovative scheme capable of enhancing bamboo's load-bearing by filling the cavity with cement mortar. Furthermore, a study was carried out to experiment flexural load carrying capacity and the deflection of mortar-filled structural bamboo by considering the diameter and node parameters. A total of 12 specimens were examined using a four-point bending protocol. The result showed the ultimate flexural load carrying capacity of mortar-filled bamboo specimens are higher than those of the conventional bamboo specimens. Specifically, mortar filled bamboo specimen with a diameter of 70 mm was significantly better, 41.10 and 47.06%, as compared than the conventional bamboo in terms of its flexural load carrying capacity for specimen without and with nodes, respectively. Increases in flexural load carrying capacity were also observed for the mortar-filled bamboo specimens having 80 and 90 mm diameter and these observed increases were recorded as 104.55 and 112.00%, and 48.72 and 60.74%, respectively for specimen without and with nodes. Furthermore, the deflection of mortar-filled bamboo elements are substantially greater than those of conventional. Finally, the advantages of the bamboo diameter and bamboo nodes on the flexural load carrying capacity indicated that these essential findings need to be carefully considered in designing structural elements for both mortar-filled and conventional bamboos.

scholarly journals Theoretical design of innovative cold formed steel beam sections

2015 ◽  
Vol 3 (2) ◽  
pp. 255
Author(s):  
M. Adil Dar ◽  
Deepankar K. Ashish ◽  
A. R. Dar
Keyword(s):  
Construction Industry ◽  
Load Carrying Capacity ◽  
Structural Elements ◽  
Buckling Modes ◽  
Steel Sheets ◽  
Modes Of Failure ◽  
Theoretical Design ◽  
Load Carrying ◽  
Cold Formed Steel ◽  
Hot Rolled

<p>In today’s world, the construction industry both structural and non-structural elements are fabricated from thin gauges of steel sheets. These thin walled sections are being used as columns, beams, joists, studs, floor decking, built-up sections and other components for lightly loaded structures. Unlike hot rolled sections, the design of Cold-Formed Steel (CFS) section for beam is predominantly controlled by various buckling modes of failure, thereby drastically reducing their load carrying capacity. Hence there is an urgent need in the CFS industry to look beyond the conventional CFS beam sections and investigate newly proposed innovative CFS beam sections, which seem to prove structurally much more efficient. Prior to any experimental investigation of innovative beam sections, there is a need to carry out theoretical design using some of the most appropriate available methods applicable to the case under consideration. This paper focuses on such theoretical designs for various innovative sections using available analytical design tools together with appropriate codal guidelines.</p>

Innovative Systems for Seismic Protection of Precast Industrial Buildings

2013 ◽  
Vol 274 ◽  
pp. 117-120 ◽  
Author(s):  
Marco Valente
Keyword(s):  
Seismic Vulnerability ◽  
Structural Elements ◽  
Rotation Capacity ◽  
Industrial Buildings ◽  
Precast Buildings ◽  
Dynamic Analyses ◽  
Connection System ◽  
Energy Dissipation Capacity ◽  
Nonlinear Dynamic Analyses ◽  
Column Base

An innovative dissipative (INERD Pin) connection system, which was previously developed for seismic resistant X-braced steel frames, was applied to retrofit existing precast industrial buildings designed only for gravity loads. Nonlinear dynamic analyses were carried out and the effectiveness of the dissipative connection system was evaluated. The INERD Pin connection system increased both the deformation capacity and the stiffness of the buildings, reducing damage of the structural elements. In case of low seismic actions, the INERD Pin connection system especially enhanced the stiffness of the structure, causing only small reductions of column rotations and top displacements. In case of severe seismic actions, the addition of the dissipative connections showed all its effectiveness particularly for low rotation capacity at column base, increasing the energy dissipation capacity and reducing the displacements of the structure. The results of the numerical investigations demonstrated the possibility to reduce the seismic vulnerability of existing precast buildings by means of dissipative connection systems.

scholarly journals Suggestion of Safety Certification Standards and Performance Evaluation Methods for Fabricated Mobile Scaffold in South Korea

2021 ◽  
Vol 19 (1) ◽  
pp. 133
Author(s):  
Heesoo Kim ◽  
Jeonghyeon Lim ◽  
Jeong-Hun Won ◽  
Jun-Hyuk Kwon ◽  
Seungjun Kim
Keyword(s):  
Performance Evaluation ◽  
Carrying Capacity ◽  
Evaluation Methods ◽  
Structural Safety ◽  
Structural Performance ◽  
Load Carrying Capacity ◽  
Safety Certification ◽  
Load Carrying ◽  
Certification Standards ◽  
And Performance

At construction sites, various types of temporary equipment and structures are used for safety and work efficiency. However, various temporary equipment-related accidents frequently occur for many reasons, including inappropriate installation, usage, and material and structural imperfections. A mobile scaffold is one of the most commonly used indoor temporary equipment for work in high places. In general, the main structural members of the mobile scaffold, such as the mainframes, horizontal members, braces, caster wheels, outriggers, and handrails, are installed on the construction site for this purpose. This means that the load-carrying capacity of the equipment can vary depending on the assembly details. In Korea, there are safety certification standards applied for frequently used temporary equipment, such as scaffolds and shoring. However, the standards concern the strength criteria for the member itself, rather than the global load-carrying capacity. Therefore, it is difficult to review whether the fabricated mobile scaffold has sufficient load-carrying capacity, or to confirm the structural safety considering the various uncertainties affecting the structural performance. In this study, rational safety certification standards and evaluation methods are suggested for fabricated mobile scaffolds. The suggested safety certification standards present structure-level criteria for checking the load-carrying capacity, horizontal stiffness of the structure, and overturning risk. It is expected that the structural performance for safety can be directly checked based on the suggested safety certification standards and performance evaluation methods during the safety certification stage.

scholarly journals Theoretical Study on the Flexural Behavior of Structural Elements Strengthened with External Pre-Stressing Methods

2021 ◽  
Vol 12 (1) ◽  
pp. 171
Author(s):  
Gouda A. Mohamed ◽  
Ahmed S. Eisa ◽  
Pavol Purcz ◽  
Mohamed H. El-Feky
Keyword(s):  
Carrying Capacity ◽  
Load Capacity ◽  
Flexural Behavior ◽  
Load Carrying Capacity ◽  
Structural Elements ◽  
Vertical Loading ◽  
Rc Frames ◽  
External Tendons ◽  
Straight Line ◽  
Load Carrying

This study aims to strengthen the flexural behavior of structural elements with external pre-stressing tendons, thereby improving their load-carrying capacity and increasing their resistance against the external load. Different techniques were used to apply external pre-stressed strengthening to RC beams and RC frames. Seven identical RC frames were analyzed: an original sample without an external tendon, two strengthened samples with external tendons at the positive bending zone, two strengthened samples with external tendons at the beam–column connection zone, a strengthened sample with external straight line tendons along the beam and, finally, a strengthened sample with external U-shape tendons along the beam of the frame. The analysis and the results were obtained using ANSYS WORKBENCH finite element (FE) program. Comparisons were performed between these techniques to determine which technique is better for strengthening. The failure mode, vertical deflection, column stress, load-carrying capacity, and ductility of the samples were listed and analyzed under four-point vertical loading. The results show that using external tendons significantly increases the load capacity and the stiffness of structural frames. Moreover, the tendon in the beam zone is more effective than the tendon in the column zone.

scholarly journals The Selected Issues of Adaptation of 19th and 20th Century Post-Industrial Buildings in Łódź

2020 ◽  
Vol 5 (8) ◽  
pp. 69
Author(s):  
Tadeusz Urban ◽  
Michał Gołdyn
Keyword(s):  
Cast Iron ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Reinforced Concrete Structure ◽  
Technical Problems ◽  
Historical Structures ◽  
Industrial Buildings ◽  
Load Carrying ◽  
Historical Masonry ◽  
Post Industrial

The paper deals with selected technical problems related to the adaptation for new uses of the structure of existing post-industrial buildings from the turn of the 19th and 20th centuries. A major difficulty is the fact that the strength and geometric properties of cast-iron, steel, and masonry elements often differ significantly from the values characterizing contemporary materials. Due to uncertainty regarding the load-carrying capacity of historical structures, in many cases there is a need to carry out destructive tests of elements taken from the buildings. As the example of cast-iron girders in the former spinning mill of “I. Poznański” demonstrated, such tests can prove a significant margin of load-carrying capacity and confirm the possibility of adapting the structure to new purposes. The paper also presents examples of strengthening the existing wooden ceilings by joining with the reinforced concrete structure, which allowed the keeping of the original elements and an increase of the allowable load. Selected problems related to the assessment of historical masonry structures were also described. The discussed examples of structural failures showed that they often resulted from incorrect assessment of the strength of historical masonry elements as well as improperly conducted construction works.

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