scholarly journals Development and Calibration of a 3D Micromodel for Evaluation of Masonry Infilled RC Frame Structural Vulnerability to Earthquakes

Geosciences ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 468
Author(s):  
Filip Anić ◽  
Davorin Penava ◽  
Vasilis Sarhosis ◽  
Lars Abrahamczyk
Keyword(s):  
Material Model ◽  
Masonry Wall ◽  
Reinforced Concrete Frame ◽  
Computational Stability ◽  
Infill Walls ◽  
Physical Test ◽  
Concrete Frame ◽  
Out Of Plane ◽  
Masonry Material ◽  
Damage States

Within the scope of literature, the influence of openings within the infill walls that are bounded by a reinforced concrete frame and excited by seismic drift forces in both in- and out-of-plane direction is still uncharted. Therefore, a 3D micromodel was developed and calibrated thereafter, to gain more insight in the topic. The micromodels were calibrated against their equivalent physical test specimens of in-plane, out-of-plane drift driven tests on frames with and without infill walls and openings, as well as out-of-plane bend test of masonry walls. Micromodels were rectified based on their behavior and damage states. As a result of the calibration process, it was found that micromodels were sensitive and insensitive to various parameters, regarding the model’s behavior and computational stability. It was found that, even within the same material model, some parameters had more effects when attributed to concrete rather than on masonry. Generally, the in-plane behavior of infilled frames was found to be largely governed by the interface material model. The out-of-plane masonry wall simulations were governed by the tensile strength of both the interface and masonry material model. Yet, the out-of-plane drift driven test was governed by the concrete material properties.

scholarly journals Shake Table Response of Unreinforced Masonry and Reinforced Concrete Elements of Special Moment Resisting Frame

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Syed Azmat Ali Shah ◽  
Junaid Shah Khan ◽  
Syed Muhammad Ali ◽  
Khan Shahzada ◽  
Waqar Ahmad ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Shake Table ◽  
Base Excitation ◽  
Reinforced Concrete Frame ◽  
Infill Walls ◽  
Concrete Frame ◽  
Moment Resisting

Half-scaled reinforced concrete frame of two storeys and two bays with unreinforced masonry (URM) infill walls was subjected to base excitation on a shake table for seismic performance evaluation. Considering the high seismic hazard Zone IV of Pakistan, reinforcement detailing in the RC frame is provided according to special moment resisting frames (SMFRs) requirement of Building Code of Pakistan Seismic-Provisions (BCP SP-2007). The reinforced concrete frame was infilled with in-plane solid masonry walls in its interior frame, in-plane masonry walls with door and window openings in the exterior frame, out-of-plane solid masonry wall, and masonry wall with door and window openings in its interior frame. For seismic capacity qualification test, the structure was subjected to three runs of unidirectional base excitation with increasing intensity. For system identification, ambient-free vibration tests were performed at different stages of experiment. Seismic performance of brick masonry infill walls in reinforced concrete frame structures was evaluated. During the shake table test, performance of URM infill walls was satisfactory until design ground acceleration was 0.40g with a global drift of 0.23%. The test was continued till 1.24g of base acceleration. This paper presents key findings from the shake table tests, including the qualitative damage observations and quantitative force-displacement, and hysteretic response of the test specimen at different levels of excitation. Experimental results of this test will serve as a benchmark for validation of numerical and analytical models.

scholarly journals Experimental in-plane performance of insulated concrete and brick masonry wall panels retrofitted using polymer composites

2018 ◽  
Vol 51 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Najif Ismail ◽  
Tamer El-Maaddawy ◽  
Amanullah Najmal ◽  
Nouman Khattak
Keyword(s):  
Single Layer ◽  
Masonry Wall ◽  
Brick Masonry ◽  
Experimental Program ◽  
Reinforced Concrete Frame ◽  
Infill Walls ◽  
Concrete Frame ◽  
Strain Behaviour ◽  
Ductility Capacity ◽  
Strength Increment

Masonry infilled reinforced concrete frame buildings built prior to the introduction of modern seismic provisions have been observed to undergo damage in and around the masonry infill walls during most recent moderate to severe earthquakes. Fibre reinforced cementitious matrix (FRCM) is one of several retrofitting options available to limit such earthquake induced damage to infill walls. An experimental program was undertaken herein to experimentally investigate the effectiveness of FRCM as a strengthening solution for vintage (i.e. built between 1880 and 1930) un-reinforced brick masonry (URM) and insulated concrete masonry (IMU) infill walls. A total of 16 masonry assemblages were tested under in-plane diagonal load, of these 8 were constructed replicating vintage URM whereas the remainder were constructed using modern IMU. IMU is a preferred masonry type in hot and humid regions owing to its superior insulting capability. Different polymer fabrics (i.e., carbon, glass and basalt) were applied over both faces of test walls, with two replicate test walls receiving the same FRCM strengthening details. One test wall of each masonry type was tested as-built to serve as a control specimen for comparison. One wall of each masonry type received two layers of basalt FRCM. The investigated aspects included stress-strain behaviour, stiffness, and ductility. Shear strength increment observed due to single layer of FRCM application was 422-778% for vintage URM and 307-415% for modern IMU. FRCM also substantially increased the ductility capacity of the masonry assemblages.

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.

Recent Results on Masonry Infill Walls

2010 ◽  
Vol 133-134 ◽  
pp. 27-30 ◽  
Author(s):  
K.J. Willam ◽  
C. Citto ◽  
P.B. Shing
Keyword(s):  
San Diego ◽  
Reinforced Concrete Frame ◽  
Infill Walls ◽  
Masonry Infill ◽  
Main Research ◽  
Masonry Infill Walls ◽  
Concrete Frame ◽  
Research Findings ◽  
Masonry Prism ◽  
Insight Into

The paper summarizes the main research findings on masonry infill walls which were obtained within the framework of a comprehensive NSF-NEESR-SG project directed by Prof. Benson Shing at UC San Diego (Shing et al. 2009). The main focus of this contribution are experimental and computational observations on 2/3 scale unreinforced masonry panels bounded by a reinforced concrete frame which were subjected to cyclic push-over testing at CU Boulder under constant vertical pre-loading. This study included two-wythe masonry panels of 133in x75.5in size (3.378 x1.897m) with and without openings in form of eccentric windows and doors. The background experiments did include a suite of masonry prism tests on rectilinear and slanted masonry prisms providing important insight into the composite behavior of mortar and brick construction. The paper concludes with remarks on the experimental observations when the panels were integrated into infill walls of two-bay width and three-story height with and without retrofits of reinforced ECC layers (engineered cementitious composites) which were attached to one side for quasistatic testing at CU Boulder, and to both sides of the wall for dynamic shake table testing at UC San Diego.

Response of Mid-Rise Reinforced Concrete Frame Buildings to the 2017 Puebla Earthquake

2019 ◽  
Vol 35 (4) ◽  
pp. 1763-1793 ◽  
Author(s):  
Carlos A. Arteta ◽  
Julian Carrillo ◽  
Jorge Archbold ◽  
Daniel Gaspar ◽  
Cesar Pajaro ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
The United States ◽  
Rc Buildings ◽  
Reinforced Concrete Frame ◽  
Infill Walls ◽  
Concrete Frame ◽  
Soft Story ◽  
Masonry Infills ◽  
Rc Frames ◽  
Ductility Capacity

The response of mid-rise reinforced concrete (RC) buildings in Mexico City after the 2017 Puebla Earthquake is assessed through combined field and computational investigation. The Mw 7.1 earthquake damaged more than 500 buildings where most of them are classified as mid-rise RC frames with infill walls. A multinational team from Colombia, Mexico, and the United States was rapidly deployed within a week of the occurrence of the event to investigate the structural and nonstructural damage levels of over 60 RC buildings with 2–12 stories. The results of the study confirmed that older mid-rise structures with limited ductility capacity may have been shaken past their capacity. To elucidate the widespread damage in mid-rise RC framed structures, the post-earthquake reconnaissance effort is complemented with inelastic modeling and simulation of several representative RC framing systems with and without masonry infill walls. It was confirmed that the addition of non-isolated masonry infills significantly impacts the ductility capacity and increases the potential for a soft-story mechanism formation in RC frames originally analyzed and designed to be bare systems.

SEISMIC RETROFIT OF NONDUCTILE REINFORCED CONCRETE FRAME AND MASONRY BUILDINGS

2019 ◽  
Vol 2 (Special Issue on First SACEE'19) ◽  
pp. 143-164
Author(s):  
Murat Saatcioglu
Keyword(s):  
Reinforced Concrete ◽  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Risk Mitigation ◽  
Seismic Retrofit ◽  
Masonry Wall ◽  
System Level ◽  
Reinforced Concrete Frame ◽  
Existing Building ◽  
Concrete Frame

A large proportion of existing building and bridge infrastructure across the world consists of seismically deficient non-ductile structural systems. Performance of structures during recent earthquakes have demonstrated seismic vulnerability of these systems, the majority of which were designed prior to the enactment of modern seismic codes, though some were designed more recently in areas where code enforcement provides challenges. These structures constitute considerable seismic risk, especially in large metropolitan centres. Because it is economically not feasible to replace a large segment of seismically deficient infrastructure with new and improved systems, retrofitting existing structures remains to be a viable seismic risk mitigation strategy. The objective of this paper is to highlight seismic retrofit strategies for deficient building and bridge infrastructures, with emphasis on experimental and analytical research conducted at the University of Ottawa. The retrofit strategies consist of structural upgrades at the system level, as well as at the element level. Non-ductile reinforced concrete frame retrofits, in the form of lateral bracing techniques, and concrete column and masonry wall retrofit methodologies are discussed. The use of innovative materials and techniques are presented.

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.

Out-of-Plane Behavior of Masonry Walls Strengthened with Ferrocement

2010 ◽  
Vol 163-167 ◽  
pp. 3545-3550 ◽  
Author(s):  
Sheng Ping Chen
Keyword(s):  
Volume Fraction ◽  
Load Capacity ◽  
Experimental Studies ◽  
Material Model ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Ultimate Load Capacity ◽  
Softening Behavior ◽  
Reinforced Masonry ◽  
Out Of Plane

Un-reinforced masonry (URM) structures may fail and collapse under out-of-plane loads generated by seismic forces or explosions. Adding a ferrocement overlay onto the URM walls is an effective solution in increasing the ultimate load capacity and ductility. This paper deals with the numerical and experimental studies on the out-of-plane behavior of un-reinforced masonry walls strengthened with ferrocement. The material parameters considered are the volume fraction of reinforcement and the loading area. A numerical model was proposed to simulate the experimental results. The employed material model for masonry wall is based on the theory of Drucker-Prager plasticity taking into account the tension softening behavior, while the ferrocement is modeled as a composite material with linear strain hardening followed by ideal plasticity. The proposed model simulates the load-deflection behavior of the strengthened wall well.

Sign in / Sign up

Export Citation Format

Share Document