The Use of Moment-Resisting Frames and Braced Frames for Lateral Stability of Multy-Storey Precast Concrete Structures

2017 ◽  
Vol 259 ◽  
pp. 173-177
Author(s):  
Arthur L. Rocha ◽  
Marcelo de A. Ferreira ◽  
Wilian dos S. Morais ◽  
Bruna Catoia
Keyword(s):  
High Performance ◽  
Precast Concrete ◽  
Tall Buildings ◽  
Shear Walls ◽  
Order Effects ◽  
Lateral Stability ◽  
Infill Walls ◽  
Precast Buildings ◽  
Moment Resisting ◽  
Lateral Displacements

Precast structures for multi-storey buildings can be designed with economy, safety and high performance. However, depending on the height of the building and the intensity of the lateral loads, the lateral stability system must be carefully chosen in order to maximize the global structural performance. In Brazil, the most common method for lateral stability is achieved by moment resisting precast-frames, wherein the moment-rotation response of the beam-column connections are responsible to provide the frame action, which will govern the distribution of internal forces and the sway distribution along the building height. On the other hand, in Europe, bracing systems comprised by shear walls or infill walls are mostly used, wherein beam-column connections are designed as hinged. The aim of this paper is to present a comparison between these methods for lateral stability, applying nine structural simulations with moment resisting precast-frames, shear walls and infill walls solutions, divided in three groups - 3 building with 5 storeys (21 meters high), 3 buildings with 10 storeys (41 meters high) and 3 building with 20 storeys (81 meters high). All first storeys are 5 meters high, while all the others are 4 meters high. The results from all structural analyses are compared. As conclusion, while moment-resisting beam-column connections are more feasible for applying in low-rise precast buildings, the use of shear walls and infill walls are more efficient for tall buildings due to decrease of lateral displacements, having a reduction of second order effects but also increasing the reactions at the foundations of bracing elements.

COMPARISON OF SHEAR WALLS AND MOMENT-RESISTING FRAMES IN EARTHQUAKE RESISTING BUILDINGS’ DESIGN

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Ahmad Sheikh Abdallah ◽  
Safwan Chahal
Keyword(s):  
Seismic Response ◽  
Tall Buildings ◽  
Shear Walls ◽  
Shear Wall ◽  
Structural Systems ◽  
Lateral Loads ◽  
Building Height ◽  
Seismic Zones ◽  
Prime Concern ◽  
Moment Resisting

The rapid growth of urban population and limited land space have greatly influenced the development of high-rise structures. Lateral loads have an important effect on the design as the building height increases. In order to resist lateral loads, safety and minimum damage should be the prime concern when designing tall buildings. To meet these requirements, the structure should have adequate lateral strength and lateral stiffness and sufficient ductility. Among the various structural systems, shear wall systems or moment resisting frame systems could be a point of choice for designers. Thus, it is important to review and observe the behavior of these systems under seismic effect. This study compared the seismic response of the above structural systems using a case study application at variable seismic zones (Zone 2B, Lebanon Zone, Zone 3, and Zone 4) and at different building stories (Eight and 12-story building). The seismic response is measured in term of time-period, maximum story displacement, maximum story drift, amount of steel and concrete needed. The outcome of this study portrayed that a shear wall system is more efficient in terms of cost and lateral load resistivity regardless of the building height and in the four seismic zones mentioned before.

Retrofit of Non-Ductile Moment-Resisting Frames Using Precast Infill Wall Panels

1996 ◽  
Vol 12 (4) ◽  
pp. 741-760 ◽  
Author(s):  
Robert J. Frosch ◽  
Wanzhi Li ◽  
James O. Jirsa ◽  
Michael E. Kreger
Keyword(s):  
Precast Concrete ◽  
Construction Time ◽  
Infill Wall ◽  
Infill Walls ◽  
Existing Building ◽  
Existing Structures ◽  
Concrete Panels ◽  
Moment Resisting Frames ◽  
Frame Element ◽  
Moment Resisting

Many existing reinforced concrete moment-resisting frames located in seismic zones lack strength and ductility. One approach for correcting these deficiencies is the construction of infill walls to strengthen and stiffen the structure. Cast-in-place construction is often used; however, there are conditions where cost, time constraints, or limiting disruptions to building operations may dictate other solutions. One possible modification is the use of infill walls constructed of precast concrete panels. A precast infill wall system eliminates the need for large formwork during construction. Elimination or reduction of connection hardware between precast panels or between panels and the existing frame element can provide additional efficiency. Problems associated with casting large quantities of concrete in an existing building are eliminated. Construction time and inconvenience to occupants may be reduced along with the costs. The precast system has the potential of reducing the overall costs of rehabilitating existing structures.

Stiffening of Moment-Resisting Frame by Precast Concrete Cladding

PCI Journal ◽  
1992 ◽  
Vol 37 (5) ◽  
pp. 80-92 ◽  
Author(s):  
Regina Gaiotti ◽  
Bryan Stafford Smith
Keyword(s):  
Precast Concrete ◽  
Moment Resisting Frame ◽  
Moment Resisting

scholarly journals Influence of Rapid Heat Treatment on the Shrinkage and Strength of High-Performance Concrete

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4102
Author(s):  
Jan Stindt ◽  
Patrick Forman ◽  
Peter Mark
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
High Performance Concrete ◽  
Treatment Time ◽  
Precast Concrete ◽  
Concrete Strength ◽  
Shrinkage Strain ◽  
Temperature Treatment ◽  
Production Flow ◽  
Steel Fibres

Resource-efficient precast concrete elements can be produced using high-performance concrete (HPC). A heat treatment accelerates hardening and thus enables early stripping. To minimise damages to the concrete structure, treatment time and temperature are regulated. This leads to temperature treatment times of more than 24 h, what seems too long for quick serial production (flow production) of HPC. To overcome this shortcoming and to accelerate production speed, the heat treatment is started here immediately after concreting. This in turn influences the shrinkage behaviour and the concrete strength. Therefore, shrinkage is investigated on prisms made from HPC with and without steel fibres, as well as on short beams with reinforcement ratios of 1.8% and 3.1%. Furthermore, the flexural and compressive strengths of the prisms are measured directly after heating and later on after 28 d. The specimens are heat-treated between 1 and 24 h at 80 °C and a relative humidity of 60%. Specimens without heating serve for reference. The results show that the shrinkage strain is pronouncedly reduced with increasing temperature duration and rebar ratio. Moreover, the compressive and flexural strength decrease with decreasing temperature duration, whereby the loss of strength can be compensated by adding steel fibres.

scholarly journals A Review on Improved Design Techniques for High Performance Planar Waveguide Slot Arrays

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1311
Author(s):  
Giovanni Andrea Casula ◽  
Giuseppe Mazzarella ◽  
Giorgio Montisci ◽  
Giacomo Muntoni
Keyword(s):  
Planar Waveguide ◽  
High Performance ◽  
Order Effects ◽  
Waveguide Slot ◽  
Waveguide Bends ◽  
Radar Systems ◽  
Slot Arrays ◽  
Planar Array ◽  
Improved Design ◽  
Design Techniques

Planar waveguide slot arrays (WSAs) have been used since 1940 and are currently used as performing antennas for high frequencies, especially in applications such as communication and RADAR systems. We present in this work a review of the most typical waveguide slot array configurations proposed in the literature, describing their main limitations and drawbacks along with possible effective countermeasures. Our attention has been focused mainly on the improved available design techniques to obtain high performance WSAs. In particular, the addressed topics have been reported in the following. Partially filled WSAs, or WSAs covered with single or multilayer dielectric slabs, are discussed. The most prominent second-order effects in the planar array feeding network are introduced and accurately modeled. The attention is focused on the T-junction feeding the array, on the effect of interaction between each slot coupler of the feeding network and the radiating slots nearest to this coupler, and on the waveguide bends. All these effects can critically increase the first sidelobes if compared to the ideal case, causing a sensible worsening in the performance of the array.

Investigation of Grouted Coupler Connection Details for Accelerated Bridge Construction

2021 ◽  
pp. 036119812199939
Author(s):  
Brent Phares ◽  
Yoon-Si Lee ◽  
Travis K. Hosteng ◽  
Jim Nelson
Keyword(s):  
Crack Width ◽  
High Performance ◽  
Static Load ◽  
High Performance Concrete ◽  
Precast Concrete ◽  
Chloride Penetration ◽  
Load Testing ◽  
Test And Evaluation ◽  
Load Tests ◽  
Precast Elements

This paper presents a laboratory investigation on the performance of grouted rebar couplers with the connection details similar to those utilized on the precast concrete elements of the Keg Creek Bridge on US 6 in Iowa. The testing program consisted of a series of static load tests, a fatigue test, and evaluation of the chloride penetration resistance of laboratory specimens. The goal of this testing was to evaluate the ability of the grouted rebar couplers to develop flexural capacity at the joint between the precast elements as well as the durability of the connection. For structural load testing, seven full-scale specimens, each with #14 epoxy-coated rebars spliced by epoxy-coated grouted couplers, were fabricated and tested in three different loading cases: four-point bending, axial tension plus bending, and a cyclic test of the system in bending. The static load testing demonstrated that the applied axial load had a minimal effect on the formation of cracks and overall performance of the connection. When ultra-high performance concrete was used as a bedding grout, the initiation of crack was slightly delayed but no considerable improvement was observed in the magnitude of the crack width during loading or the crack closure on unloading. The results of the seventh specimen, tested in fatigue to 1 million cycles, showed little global displacement and crack width throughout the test, neither of which expanded measurably. No evidence of moisture or chloride penetration was detected at the grouted joint during the 6-month monitoring.

Surrogate models for high performance control systems in wind-excited tall buildings

2020 ◽  
Vol 90 ◽  
pp. 106133 ◽  
Author(s):  
Laura Micheli ◽  
Jonathan Hong ◽  
Simon Laflamme ◽  
Alice Alipour
Keyword(s):  
Control Systems ◽  
High Performance ◽  
Tall Buildings ◽  
Surrogate Models ◽  
Performance Control

scholarly journals Experimental Investigation of Steel Plate Shear Walls under Shear-Compression Interaction

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Yang Lv ◽  
Ling Li ◽  
Di Wu ◽  
Bo Zhong ◽  
Yu Chen ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Steel Plate ◽  
Axial Stress ◽  
Shear Walls ◽  
Shear Capacity ◽  
Steel Plate Shear Walls ◽  
Steel Plate Shear Wall ◽  
Gravity Load ◽  
Moment Resisting ◽  
Axial Stress Distribution

Four scaled one-storey single-bay steel plate shear wall (SPSW) specimens with unstiffened panels were tested to determine their behaviour under cyclic loadings. The shear walls had moment-resisting beam-to-column connections. Four different vertical loads, i.e., 300 kN, 600 kN, 900 kN, and 1200 kN, representing the gravity load of the upper storeys were applied at the top of the boundary columns through a force distribution beam. A horizontal cyclic load was then applied at the top of the specimens. The specimen behaviour, envelope curves, axial stress distribution of the infill steel plate, and shear capacity were analyzed. The axial stress distribution and envelope curves were compared with the values predicted using an analytical model available in the literature.

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