Seismic behavior of a partially grouted reinforced masonry structure: Shake‐table testing and numerical analyses

Abstract

In regions of low to moderate seismicity in North America, reinforced masonry structures are mostly partially grouted. The behavior of such structures under lateral seismic loads is complicated because of the interaction of the grouted and ungrouted masonry. As revealed in past experimental studies, the performance of partially grouted masonry (PGM) walls under in-plane cyclic lateral loading is inferior to that of fully grouted walls. However, the dynamic behavior of a PGM wall system under severe seismic loads is not well understood. In this study, a full-scale, one-story, PGM building designed for a moderate seismic zone according to current code provisions was tested on a shake table. It was shown that the structure was able to develop an adequate base shear capacity and withstand two earthquake motions that had an effective intensity of two times the maximum considered earthquake with only moderate cracking in mortar joints. However, the structure eventually failed in a brittle manner in a subsequent motion that had a slightly lower effective intensity. A detailed finite element model of the test structure has been developed and validated. The model has been used to understand the distribution of the lateral force resistance among the wall components and to evaluate the shear-strength equation given in the design code. The code equation has been found to be adequate for this structure. Furthermore, a parametric study conducted with the finite element model has shown that the introduction of a continuous bond beam right below a window opening is highly beneficial.

Finite‐element modeling of the seismic response of reinforced masonry wall structures

“…The force vector is then transformed to the global coordinate system following the standard coordinate transformation 53 . Further details can be found in Koutras 54 …”

Detailed micro-modeling of partially grouted reinforced masonry shear walls: extended validation and parametric study

“…This situation can be attributed to the fact that the bond beams and grouted vertical hollows create a confining frame that turns RM into confined masonry to some extent [9,13], a situation that does not occur in BJR-PG-RM shear walls. More recently, Koutras and Shing [8] and Calderón et al [12] reproduced the behavior of PG-RM walls of HCBs using 3D and 2D simplified micro-modeling approaches, respectively, reporting accurate results. In both studies, the mortar joints were reduced to interfaces, which requires adopting a constitutive law that represents the response of the mortar and the unitmortar contact zones at the same time.…”

“…However, experimentation is a resource-demanding activity in many aspects (e.g., funding, equipment, handwork, time, among others). This issue has motivated many researchers (e.g., [6][7][8][9][10][11][12], among others) to develop computational analysis methodologies to reproduce the behavior of PG-RM masonry specimens.…”

A beam‐column element for modeling nonlinear flexural and shear behaviors of reinforced masonry walls

“…The ability to model the flexural and shear behaviors of a masonry wall system is of critical importance for performance‐based seismic design and assessment. Detailed finite element models using continuum elements and zero‐thickness interface elements have been developed to simulate these behaviors with a high degree of accuracy 6–11 . While these models are the most general and accurate computational tools for capturing the global and local damage behaviors and response of a wall system, they are computationally demanding and are not suitable for general use in engineering practice or for computationally intensive evaluation procedures, such as the FEMA P695 procedure, 12 which requires incremental dynamic analysis to evaluate the collapse probability of a seismic force resisting system.…”