Displacement capacity of contemporary unreinforced masonry walls: An experimental study

Salmanpour, Amir Hosein; Mojsilović, Nebojša; Schwartz, Joseph

doi:10.1016/j.engstruct.2015.01.052

Cited by 76 publications

(60 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The selection criteria for the experimental campaigns are as follows: (1) wall height ≥ 1.5 m, wall length ≥ 1.0 m; (2) constant shear span during test; (3) constant axial load during test, and (4) availability of the force‐displacement history. The considered results are obtained from 10 campaigns and comprise 79 specimens (Table ). The main parameters of each test are summarized in Table in Appendix A.…”

Section: Experimental Evidencementioning

confidence: 99%

The effective stiffness of modern unreinforced masonry walls

Wilding

Beyer

2018

Earthq Engng Struct Dyn

View full text Add to dashboard Cite

Summary Code design of unreinforced masonry (URM) buildings is based on elastic analysis, which requires as input parameter the effective stiffness of URM walls. Eurocode estimates the effective stiffness as 50% of the gross sectional elastic stiffness, but comparisons with experimental results have shown that this may not yield accurate predictions. In this paper, 79 shear‐compression tests of modern URM walls of different masonry typologies from the literature are investigated. It shows that both the initial and the effective stiffness increase with increasing axial load ratio and that the effective‐to‐initial stiffness ratios are approximately 75% rather than the stipulated 50%. An empirical relationship that estimates the E‐modulus as a function of the axial load and the masonry compressive strength is proposed, yielding better estimates of the elastic modulus than the provision in Eurocode 6, which calculates the E‐modulus as a multiple of the compressive strength. For computing the ratio of the effective to initial stiffness, a mechanics‐based formulation is built on a recently developed analytical model for the force‐displacement response of URM walls. The model attributes the loss in stiffness to diagonal cracking and brick crushing, both of which are taken into account using mechanical considerations. The obtained results of the effective‐to‐initial stiffness ratio agree well with the test data. A sensitivity analysis using the validated model shows that the ratio of effective‐to‐initial stiffness is for most axial load ratios and wall geometries around 75%. Therefore, a modification of the fixed ratio of effective‐to‐initial stiffness from 50% to 75% is suggested.

show abstract

Section: Experimental Evidencementioning

confidence: 99%

The effective stiffness of modern unreinforced masonry walls

Wilding

Beyer

2018

Earthq Engng Struct Dyn

View full text Add to dashboard Cite

show abstract

“…Furthermore, as can be clearly seen from the hysteretic behaviour of the masonry walls a significant degradation of stiffness K 0 during cyclic loading can be observed. Figure 2 shows exemplarily the stiffness degradation for three tests of the Series T (Salmanpour et al 2015).…”

Section: Effective Stiffness Of Masonrymentioning

confidence: 99%

“…the loop corresponding to the first applied displacement cycle, see also Salmanpour et al (2015) could be used to obtain the effective stiffness. However, as shown in Figure 1, the ratio between the tangent stiffness, K 0 , and the effective stiffness as well as between the elastic stiffness and the effective stiffness for clay block masonry walls, is scattered and the latter ratio is, in most cases, much smaller than 0.5.…”

Section: Effective Stiffness Of Masonrymentioning

confidence: 99%

Seismic strengthening of a theatre masonry building by using active FRP wires

Micelli¹,

Cascardi²,

Marsano³

2016

Brick and Block Masonry

View full text Add to dashboard Cite

This paper describes the procedure on the evaluation of the masonry chapter for the next generation of Eurocode 8, the European Standard for earthquake-resistant design.In CEN, TC 250/SC8, working group WG 1 has been established to support the subcommittee on the topic of masonry on both design of new structures (EN1998-1) and assessment of existing structures (EN1998-3).The aim is to elaborate suggestions for amendments which fit the current state of the art in masonry and earthquake-resistant design. Focus will be on modelling, simplified methods, linear-analysis (q-values, overstrength-values), nonlinear procedures, out-of-plane design as well as on clearer definition of limit 696 states. Beside these, topics related to general material properties, reinforced masonry, confined masonry, mixed structures and non-structural infills will be covered too. This paper presents the preliminary work and results up to the submission date.ings, pushover analysis is widely used in assessment and design of masonry buildings in several moderate to high seismicity countries in Europe.This diffusion and use of pushover analysis for masonry structures (much more common than for concrete and steel structures) calls for a general revision of the procedure currently proposed in EC8, which needs further specifications to be fully applicable to masonry buildings (e.g. displacement/drift limits) as it is for example the procedure proposed in the Italian Building code (NTC, 2008) and its commentary.Several aspects, also related to modelling requirements, definition of capacity and simplified evaluation of the displacement demand, need to be considered. They are summarised in the following subsections. Pushover analysis procedureA general revision of the pushover analysis procedure includes the review of the applicability conditions of pushover analysis for design and assessment, which may be related to the structural regularity and the characteristics of the horizontal diaphragms. Also, the definition of a standard pushover analysis algorithm (e.g. displacement control with constant load pattern) and possible alternatives (e.g. adaptive, multi-modal) could be considered.A suitable procedure for converting the pushover curve into a bilinear capacity curve for an equivalent single-degree-of-freedom system needs to be specifically defined for the case of masonry structures.Moreover, the simplified formulae for the determination of the displacement demand which are currently reported in EC8 (Fajfar, 2000) were developed for structural systems with periods of vibration longer than those typical of masonry structures and were characterized by different hysteretic behaviours. For these reasons, possible modifications to the current formulae will be considered (Graziotti, 2013).Displacement-based safety checks also require the definition of appropriate displacement limit states, based on member drift capacity and/or alternative criteria for the definition of global limit states. Structural models for pushover analysisSpatial buil...

show abstract

“…It is assumed that the wall has the same geometric and material properties, Table 2, as the walls used in the full-scale experiment carried out at the ETH Zurich, see [25]. In that experiment seven typical Swiss clay hollow block masonry walls with different boundary conditions and pre-compression levels were tested up to failure.…”

Section: Case Of Masonry Reliability Analysis: a Slip Failure Along Hmentioning

confidence: 99%

Reliability of masonry walls subjected to in‐plane loading: A slip failure along head joints / Zuverlässigkeit von Mauerwerkswänden bei Belastung in der Ebene: Versagen entlang der Stoßfugenflucht

2016

Self Cite

View full text Add to dashboard Cite

Masonry structures are a sustainable, economical and traditionally widely used type of construction. However, current masonry design codes are rather conservative, so there is a growing need for revision i.e. calibration of safety factors to improve the allocation of material resources. In this paper, we investigate the probability of occurrence of slip failure along head joints (perpends) in masonry subjected to in‐plane loading. An appropriate limit state function is established and the masonry material properties and loads are defined as random variables in order to simulate likelihood of occurrence of a slip failure regime along the head joints. Furthermore, an example of masonry wall with probabilistic analysis outcomes using Monte Carlo simulation is presented and recommendations for further work are provided.

show abstract

Displacement capacity of contemporary unreinforced masonry walls: An experimental study

Cited by 76 publications

References 16 publications

The effective stiffness of modern unreinforced masonry walls

The effective stiffness of modern unreinforced masonry walls

Seismic strengthening of a theatre masonry building by using active FRP wires

Reliability of masonry walls subjected to in‐plane loading: A slip failure along head joints / Zuverlässigkeit von Mauerwerkswänden bei Belastung in der Ebene: Versagen entlang der Stoßfugenflucht

Contact Info

Product

Resources

About