scholarly journals Numerical analysis of reinforced concrete frame buildings with decoupled infill walls

2020 ◽  
Vol 63 (4) ◽  
pp. 13-48
Author(s):  
Marko Marinković ◽  
Santiago Calvinisti ◽  
Christoph Butenweg
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Characteristics ◽  
Numerical Models ◽  
Rc Frame ◽  
Reinforced Concrete Frame ◽  
Infill Wall ◽  
Infill Walls ◽  
Masonry Infill ◽  
Infilled Frame ◽  
Frame Buildings

Reinforced concrete (RC) buildings with masonry infill walls are widely used in many countries all over the world. Although infills are considered as non-structural elements, they significantly change dynamic characteristics of RC frame structures during earthquake excitation. Recently, significant effort was spent on studying decoupled infills, which are isolated from the surrounding frame usually by adding a gap between frame and infill. In this case, the frame deformation does not activate infill wall, thus infills are not influencing the behaviour of the frame. This paper presents the results of the investigation of the behaviour of RC frame buildings with the INODIS system that decouples masonry infills from the surrounding frame. Effect of masonry infill decoupling was investigated first on the one-bay one-storey frame. This was used as a base for parametric study on the frames with more bays and storeys, as well as on the building level. Change of stiffness and dynamic characteristics was analysed as well as response under earthquake loading. Comparison with the bare frame and traditionally infilled frame was performed. The results show that behaviour of the decoupled infilled frames is similar to the bare frame, whereas behaviour of frames with traditional infills is significantly different and demands complex numerical models. This means that if adequate decoupling is applied, design of infilled frame buildings can be significantly simplified.

SEISMIC BEHAVIOR OF UNREINFORCED CONCRETE MASONRY INFILL WALLS

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ziad Azzi ◽  
Caesar Abi Shdid
Keyword(s):  
Reinforced Concrete ◽  
Ground Motion ◽  
Element Model ◽  
Reinforced Concrete Frame ◽  
Infill Wall ◽  
Infill Walls ◽  
Existing Building ◽  
Masonry Infill ◽  
Masonry Infill Walls ◽  
Out Of Plane

The majority of new and existing building inventories in the Middle East consist of reinforced concrete skeletal structures with outer shells composed of unreinforced masonry infill walls. In the absence of any mandatory seismic design requirements, these buildings will sustain catastrophic damage when exposed to high seismic activity. Investigating the behavior of such infill walls when exposed to ground motion is therefore an important topic. Experimental tests using shake table out-of-plane ground motion of the 1940 El Centro earthquake displacement are conducted on 3:10 scaled specimens of a single story reinforced concrete frame with a masonry infill wall in between. The test specimens are constructed with the same materials and construction practices commonly used in the region. Displacements and strains are compared with a finite element model of the frame. Moreover, the observed overall behavior of the infill is compared to that of the computer model. The recorded strains in the mortar joints exceeded cracking limits, whereas the overall stability of the wall in out-of-plane bending was not compromised. Recommendations on the use of these structural elements are formulated.

scholarly journals Rapid assessment of peak storey drift demands on reinforced concrete frame buildings

2019 ◽  
Vol 52 (3) ◽  
pp. 109-118
Author(s):  
Timothy J. Sullivan
Keyword(s):  
Reinforced Concrete ◽  
Linear Time ◽  
Rapid Assessment ◽  
Time History ◽  
Seismic Assessment ◽  
Rc Frame ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Frame Buildings ◽  
Rc Frame Buildings

The peak storey drift demands that an earthquake imposes on a building can be assessed through a detailed engineering seismic assessment or recorded if a building is instrumented. However, for the rapid seismic assessment of a large number of buildings, it is desirable to have a simplified means of estimating storey drift demands. Consequently, this paper proposes a simplified means of quickly estimating storey drift demands on reinforced concrete (RC) frame buildings. Expressions for peak storey drift demand as a function of ground motion intensity are developed by utilising concepts and simplifications available from displacement-based seismic design and assessment methods. The performance of the approach is gauged by comparing predicted storey drift demands with those obtained from rigorous non-linear time-history analyses for a number of case study buildings. The promising results suggest that the approach proposed will be useful for rapidly assessing the likelihood of damage to a range of drift-sensitive elements in modern RC frame buildings.

Erdbebensicherer Anschluss von Ausfachungsmauerwerk in Stahlbetonrahmentragwerken mit Entkopplungselementen/Earthquake resistant connection for masonry infill walls in reinforced concrete frame structures with decoupling elements

Bauingenieur ◽  
2018 ◽  
Vol 93 (09) ◽  
pp. 333-341
Author(s):  
C. Butenweg ◽  
M. Marinkovic
Keyword(s):  
Reinforced Concrete ◽  
Frame Structures ◽  
Reinforced Concrete Frame ◽  
Infill Walls ◽  
Masonry Infill ◽  
Masonry Infill Walls ◽  
Concrete Frame ◽  
Experimentelle Untersuchungen ◽  
Earthquake Resistant ◽  
Reinforced Concrete Frame Structures

Stahlbetonrahmentragwerke mit Mauerwerksausfachungen weisen nach Erdbebenereignissen häufig schwere Schäden auf, da die Ausfachungen ohne weitere konstruktive Maßnahmen mit vollem Kontakt zum Stahlbetonrahmen eingemauert werden. Durch die unplanmäßige Beteiligung am horizontalen Lastabtrag erfahren die Ausfachungen Belastungen in Wandebene und beeinflussen das globale Schwingungsverhalten der Rahmentragwerke. In Kombination mit den gleichzeitig auftretenden seismischen Trägheitskräften senkrecht zur Wand führt dies in vielen Fällen zu einem Versagen der mit niedrigen Festigkeiten ausgeführten Ausfachungen. Dies war der Anlass in dem europäischen Forschungsprojekt INSYSME ein Entkopplungssystem zu entwickeln, mit dem Rahmen und Ausfachung durch ein spezielles Profil aus Elastomeren entkoppelt werden. Das Profil ermöglicht Relativverschiebungen zwischen Rahmen und Ausfachung und stellt gleichzeitig die Aufnahme von Belastungen senkrecht zur Wand sicher. Der Beitrag erläutert zunächst den Aufbau des Systems und gibt einen Überblick über die in Kleinbauteilversuchen ermittelten Tragfähigkeiten. Zudem werden experimentelle Untersuchungen an mit hochwärmedämmenden Mauerziegeln ausgefachten Stahlbetonrahmen mit und ohne Entkopplungssystem für getrennte und kombinierte Belastungen in und senkrecht zur Wandebene vorgestellt. Auf Grundlage einer Versuchsauswertung und eines Ergebnisvergleichs werden Wirkungsweise und Effektivität des entwickelten Entkopplungssystems demonstriert.

Seismic response analyses and performance assessment of masonry-infilled reinforced concrete frame buildings in Bhutan without and with soft storey

2016 ◽  
Vol 20 (5) ◽  
pp. 822-839
Author(s):  
Kinzang Thinley ◽  
Hong Hao
Keyword(s):  
Reinforced Concrete ◽  
Return Period ◽  
Ground Motions ◽  
Reinforced Concrete Frame ◽  
Infill Wall ◽  
Soft Storey ◽  
Concrete Frame ◽  
Seismic Design Code ◽  
Frame Buildings ◽  
High Seismicity

Bhutan locates in a high seismicity region but has no seismic design code of its own. Recent devastating earthquake in Nepal, which is located in the same region as Bhutan and with similar construction types, raises the concern on the seismic safety of building structures in Bhutan. This study is aimed at assessing the performance of masonry-infilled and soft storey reinforced concrete frame buildings in Bhutan under the 475- and 2475-year return period ground motions predicted from the Probabilistic Seismic Hazard Analysis. A nonlinear strut model is used to model the infill wall, and the influence of openings and soil–structure interaction are considered in the analyses. The result suggests that the masonry-infilled reinforced concrete frame buildings in Bhutan could suffer repairable and irreparable damages under the 475-year return period ground motions and severe damages and even collapse under the 2475-year return period ground motion. The buildings with the soft storey are found to be more vulnerable than the normal masonry-infilled reinforced concrete buildings. The design recommendation of Indian Seismic Code improves the performance of soft storey buildings but cannot fully negate the soft storey effect. This study is the first such effort in assessing the performance of general building stocks in the high seismicity Bhutan. The results can guide the seismic strengthening options and can be used for further loss predictions for seismic preparedness of the country.

scholarly journals Performance of Infill Framed Structures During Earthquake: A State-of-the- Art Review

2020 ◽  
Vol 5 (3) ◽  
pp. 66-70
Author(s):  
Priyanka . ◽  
◽  
Shobha Ram ◽  
Alok Verma ◽  
Keyword(s):  
Rc Buildings ◽  
Reinforced Concrete Frame ◽  
Infill Walls ◽  
Framed Structures ◽  
Masonry Infill ◽  
Masonry Infill Walls ◽  
Failure Patterns ◽  
Concrete Frame ◽  
Frame Buildings ◽  
The World

Masonry infill walls are widely known to increase the lateral stiffness of the structure and for this reason, it is accepted all over the world. This paper presents a review work on the performance of infill framed structures that were damaged during several earthquakes. A study of the behavior of damaged buildings during different earthquakes in the world has been carried out. The mentioned earthquakes substantially caused damage to the RC buildings. The RC buildings were damaged primarily because of improper design and reinforcement detailing at the design phase and improper workmanship and quality control at the construction phase. The main objective of this paper is to describe and analyze the failure patterns observed in reinforced concrete frame buildings with masonry infill walls and without masonry infill walls all over the world.

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