The Whittier Narrows, California Earthquake of October 1, 1987—Masonry Building Performance Survey

1988 ◽  
Vol 4 (1) ◽  
pp. 181-196 ◽  
Author(s):  
G. C. Hart ◽  
J. Kariotis ◽  
J. L. Noland

The observed earthquake response of unreinforced and reinforced masonry buildings during the October 1 and 4, 1987 Whittier Narrows Earthquakes was documented in a comprehensive building survey. This paper describes the extent of the survey, the type of data collected and a preliminary summary of some survey results.

Author(s):  
Marco Corradi ◽  
Adelaja Israel Osofero ◽  
Antonio Borri ◽  
Giulio Castori

Existing un-reinforced masonry buildings made of vaults, columns and brick and multi-leaf stone masonry walls, many of which have historical and cultural importance, constitute a significant portion of construction heritage in Europe and rest of the world. Recent earthquakes in southern Europe have shown the vulnerability of un-reinforced masonry constructions due to masonry almost total lack of tensile resistance. Composite materials offer promising retrofitting possibilities for masonry buildings and present several well-known advantages over existing conventional techniques. The aim of this work is to analyze the effectiveness of seismic-upgrading methods both on un-damaged (preventive reinforcement) and damaged (repair) masonry building. After a brief description of mechanical and physical properties of composite materials, three different applications have been addressed: in-plane reinforcement of masonry walls, extrados and intrados reinforcement of masonry vaults/arches and masonry column confinement with composite materials.


Author(s):  
Marco Corradi ◽  
Adelaja Israel Osofero ◽  
Antonio Borri ◽  
Giulio Castori

Existing un-reinforced masonry buildings made of vaults, columns and brick and multi-leaf stone masonry walls, many of which have historical and cultural importance, constitute a significant portion of construction heritage in Europe and rest of the world. Recent earthquakes in southern Europe have shown the vulnerability of un-reinforced masonry constructions due to masonry almost total lack of tensile resistance. Composite materials offer promising retrofitting possibilities for masonry buildings and present several well-known advantages over existing conventional techniques. The aim of this work is to analyze the effectiveness of seismic-upgrading methods both on un-damaged (preventive reinforcement) and damaged (repair) masonry building. After a brief description of mechanical and physical properties of composite materials, three different applications have been addressed: in-plane reinforcement of masonry walls, extrados and intrados reinforcement of masonry vaults/arches and masonry column confinement with composite materials.


1995 ◽  
Vol 22 (2) ◽  
pp. 378-402 ◽  
Author(s):  
Michel Bruneau

The surface magnitude 6.8 Northridge earthquake which struck the Los Angeles area on January 17, 1994, damaged a large number of engineered buildings, of nearly all construction types. As earthquakes of at least similar strength are expected to occur in most of eastern and western Canada, the study of the effects of this earthquake is of particular significance to Canada. This paper, as part of a concerted multi-paper reporting effort, concentrates on the damage suffered by masonry buildings during this earthquake, and explains why the various types of observed failures occurred. The seismic performance of all masonry construction similar to that commonly found in Canada is reviewed, but a particular emphasis is placed on providing an overview of damage to unreinforced masonry structures which had been rehabilitated before this earthquake. To provide a better appreciation of the impact of this earthquake on masonry buildings, and a better assessment of the engineering significance of their damage in a Canadian perspective, this paper first reviews the evolution of building code requirements for unreinforced masonry buildings up to the seismic retrofit ordinances enacted prior to this earthquake. Examples of various damage types, as observed by the author during his reconnaissance visit to the stricken area, are then presented, along with technically substantiated descriptions of the causes for this damage, and cross-references to relevant clauses from Canadian standards and codes, as well as the recently published Canadian Guidelines for the Seismic Evaluation of Existing Buildings, whenever appropriate. Key words: earthquake, unreinforced masonry, seismic rehabilitation, retrofit, retrofitted masonry building, reinforced masonry, buildings, failure, collapse, heritage buildings.


Author(s):  
A. Sandoli ◽  
G. P. Lignola ◽  
B. Calderoni ◽  
A. Prota

AbstractA hybrid seismic fragility model for territorial-scale seismic vulnerability assessment of masonry buildings is developed and presented in this paper. The method combines expert-judgment and mechanical approaches to derive typological fragility curves for Italian residential masonry building stock. The first classifies Italian masonry buildings in five different typological classes as function of age of construction, structural typology, and seismic behaviour and damaging of buildings observed following the most severe earthquakes occurred in Italy. The second, based on numerical analyses results conducted on building prototypes, provides all the parameters necessary for developing fragility functions. Peak-Ground Acceleration (PGA) at Ultimate Limit State attainable by each building’s class has been chosen as an Intensity Measure to represent fragility curves: three types of curve have been developed, each referred to mean, maximum and minimum value of PGAs defined for each building class. To represent the expected damage scenario for increasing earthquake intensities, a correlation between PGAs and Mercalli-Cancani-Sieber macroseismic intensity scale has been used and the corresponding fragility curves developed. Results show that the proposed building’s classes are representative of the Italian masonry building stock and that fragility curves are effective for predicting both seismic vulnerability and expected damage scenarios for seismic-prone areas. Finally, the fragility curves have been compared with empirical curves obtained through a macroseismic approach on Italian masonry buildings available in literature, underlining the differences between the methods.


2010 ◽  
Vol 452-453 ◽  
pp. 105-108 ◽  
Author(s):  
Hong Fu Chen ◽  
Bai Tao Sun

During Wenchuan Ms 8.0 earthquake, masonry buildings have suffered severely damaged and collapsed, causing heavy casualties and huge economic losses. In this paper, based on seismic site survey data, some new phenomena and characteristics of earthquake damage in comparison with the 1976 Tangshan earthquake, such as seismic damage of large space buildings, inclined or “X” shaped crack in wall between windows or spandrel wall, stair damage, falling of precast reinforced concrete slab and horizontal crack at the bottom of structure, are discussed in detail. Then, the impact factors of seismic capacity of masonry building in Wenchuan earthquake, including construction age, seismic fortification, bay size, floor (roof) form, layer number, thickness of bearing wall are analyzed, respectively; Finally, some recommendations on seismic design and reconstruction of masonry structure by the seismic design code are proposed.


2021 ◽  
Author(s):  
Andreia Romero Fanton ◽  
Camila de Queiroz Moreira ◽  
Rangel Costa Lage ◽  
Carla Neves Costa ◽  
Luiz Carlos de Almeida ◽  
...  

<p>This paper presents a structural fire design of a loadbearing external wall from a Brazilian 3-storey structural masonry building based on Eurocode EN 1996-1-2, through an adaptation of tabular data and simplified calculation methods for buildings designed according to Brazilian standards for the ultimate and serviceability states. The building fire safety regulation of the State of São Paulo instructs the use of Eurocodes in the absence of a specific national standard for structural fire design. EN 1996-1-2 procedures are applied to provide information to Brazilian standardization, comparing results for concrete and clay units. The observed limitations in these adaptations of design methods may not be uncommon to other EU countries. Finally, for a 60-minute TRRF (Brazilian requirement), the building required a minimum thickness (Eurocode requirement) of 100/140mm for concrete units and 90/100mm for clay units.</p>


2017 ◽  
Vol 4 ◽  
pp. 24-30
Author(s):  
Shyam Sundar Basukala ◽  
Prem Nath Maskey

Historic buildings of Nepal are mainly constructed from masonry structure. Since masonry structures are weak in tension which leads to the failure of structure. So, to avoid possible damage in environment lives and property it is urgent to conduct vulnerability assessments. Seismic vulnerability of historic masonry buildings constructed in Bhaktapur at Byasi area is carried out for the case study. Five load bearing masonry buildings were selected out of 147 buildings considering opening percentage, storey and type of floor for modeling in SAP 2000 V10 Various methods of rapid visual screening (FEMA 154, EMS 98) are used to determine the vulnerability of the selected building. The Selected Building response is carried out by linear time history analysis. The seismic vulnerability of masonry structures is determined in terms of fragility curves which represent the probability of failure or damage due to various levels of strong ground motions for different damage state slight, moderate, extensive and collapse. From the result of Rapid Visual Screening (RVS) and Fragility curves of the buildings it is found that whole, buildings are found vulnerable from future earthquake.


Author(s):  
Amaryllis Mouyiannou ◽  
Andrea Penna ◽  
Maria Rota ◽  
Francesco Graziotti ◽  
Guido Magenes

The seismic capacity of a structure is a function of the characteristics of the system as well as of its state, which is mainly affected by previous damage and deterioration. The cumulative damage from repeated shocks (for example during a seismic sequence or due to multiple events affecting an unrepaired building stock) affects the vulnerability of masonry buildings for subsequent events. This paper proposes an analytical methodology for the derivation of state-dependent fragility curves, taking into account cumulated seismic damage, whilst neglecting possible ageing effects. The methodology is based on nonlinear dynamic analyses of an equivalent single degree of freedom system, properly calibrated to reproduce the static and dynamic behaviour of the structure. An application of the proposed methodology to an unreinforced masonry case study building is also presented. The effect of cumulated damage on the seismic response of this prototype masonry building is further studied by means of nonlinear dynamic analyses with the accelerograms recorded during a real earthquake sequence that occurred in Canterbury (New Zealand) between 2010 and 2012.


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