Miguelangel Rios Bilotta, and Carlos Cruz Noguez
Miguelangel Rios Bilotta, MSc student, University of Alberta, 116th St. & 85th Ave., Edmonton, AB, Canada, bilotta@ualberta.ca
Carlos Cruz Noguez, Associate Professor, Department of Civil and Environmental Engineering, University of Alberta, 116th St. & 85thAve., Edmonton, AB, Canada, cruznogu@ualberta.ca
ABSTRACT
Masonry load bearing block walls represent the most frequently used structural components between different type of masonry systems for the construction of industrial buildings. Therefore,
the development of a rationalized design procedure able to provide adequate axial capacity and bending stiffness to resist the effects of axial load and out of plane (OOP) bending is vital. The continued effort of many researchers has made possible the use of Reinforced Masonry Walls (RMWs) with increasingly higher slender ratios in current structures in Canada. Nevertheless,
developing the ideal design procedure has been a challenging and endless task. To date, most design codes do not exhibit a consistent and effective approach to consider the secondary orders
or (P-Δ) effect in Slender Masonry Walls (SMWs). The current Canadian standard (CSA S304-14) and the Building Code Requirements and Specification for Masonry Structures (TMS/402/602-
16), used in United States, have adopted the Moment Magnifier (MM) method to quantify the P- Δ effect in the design of SMWs. The methodology intends to estimate an amplification factor that depends on the Euler Buckling Load based on the actual flexural stiffness of the MW. Although the same philosophy is followed by both committees, each standard has defined different
mechanisms to obtain the parameters needed to apply the MM. A fibre finite element model has been validated on the basis of previous experimental test reports. The finite element results are compared with the current MM methods proposed by each standard and their effectiveness is evaluated. A new expression to quantify the OOP stiffness based on a regression analysis is
proposed.
KEYWORDS: reinforced masonry, slender wall, out-of-plane behaviour, moment magnifier, second-order effects, effective stiffness.
