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An accurate quantification of the displacement capacity of a reinforced masonry shear-wall system is of critical importance to seismic design because it has a direct implication on the seismic force modification factor, which is the R factor in ASCE 7. In spite of the shear capacity design requirement in TMS 402, special reinforced masonry walls within a building system could still develop shear-dominated behavior, which is perceived to be far more brittle than flexural behavior. These walls have a low shear-span ratio either because of the wall geometry (i.e., a low height-to-length ratio) or the coupling forces introduced by the horizontal diaphragms, which are often ignored in design. Although shear-dominated walls appeared to be very brittle in quasi-static tests conducted on single planar wall segments, reinforced masonry structures survived major ground shaking well in past earthquakes. This could be partly attributed to the beneficial influence of wall flanges as well as the over-strength of the system. Flanged walls are common in masonry buildings, but their behavior is not well understood because of the lack of laboratory test data. Furthermore, other walls or columns that are present in the structural system to carry gravity loads could enhance the lateral resistance of the shear walls and the displacement capacity of the system by providing axial restraints as well as alternative load paths for gravity loads. A research project is being carried out with shake-table tests to investigate the displacement capacity of shear-dominated reinforced masonry wall systems. This paper presents results of the first shake-table test conducted in this project on a full-scale single-story coupled T-wall system. The structure was tested to a drift ratio exceeding 15% without collapse. 

An accurate quantification of the displacement capacity of a reinforced masonry shear-wall system is of critical importance to seismic design because it has a direct implication on the seismic force modification factor, which is the R factor in ASCE 7. In spite of the shear capacity design requirement in TMS 402, special reinforced masonry walls within a building system could still develop shear-dominated behavior, which is perceived to be far more brittle than flexural behavior. These walls have a low shear-span ratio either because of the wall geometry (i.e., a low height-to-length ratio) or the coupling forces introduced by the horizontal diaphragms, which are often ignored in design. Although shear-dominated walls appeared to be very brittle in quasi-static tests conducted on single planar wall segments, reinforced masonry structures survived major ground shaking well in past earthquakes. This could be partly attributed to the beneficial influence of wall flanges as well as the over-strength of the system. Flanged walls are common in masonry buildings, but their behavior is not well understood because of the lack of laboratory test data. Furthermore, other walls or columns that are present in the structural system to carry gravity loads could enhance the lateral resistance of the shear walls and the displacement capacity of the system by providing axial restraints as well as alternative load paths for gravity loads. A research project is being carried out with shake-table tests to investigate the displacement capacity of shear-dominated reinforced masonry wall systems. This paper presents results of the first shake-table test conducted in this project on a full-scale single-story coupled T-wall system. The structure was tested to a drift ratio exceeding 15% without collapse. 

An accurate quantification of the displacement capacity of a reinforced masonry shear-wall system is of critical importance to seismic design because it has a direct implication on the seismic force modification factor, which is the R factor in ASCE 7. In spite of the shear capacity design requirement in TMS 402, special reinforced masonry walls within a building system could still develop shear-dominated behavior, which is perceived to be far more brittle than flexural behavior. These walls have a low shear-span ratio either because of the wall geometry (i.e., a low height-to-length ratio) or the coupling forces introduced by the horizontal diaphragms, which are often ignored in design. Although shear-dominated walls appeared to be very brittle in quasi-static tests conducted on single planar wall segments, reinforced masonry structures survived major ground shaking well in past earthquakes. This could be partly attributed to the beneficial influence of wall flanges as well as the over-strength of the system. Flanged walls are common in masonry buildings, but their behavior is not well understood because of the lack of laboratory test data. Furthermore, other walls or columns that are present in the structural system to carry gravity loads could enhance the lateral resistance of the shear walls and the displacement capacity of the system by providing axial restraints as well as alternative load paths for gravity loads. A research project is being carried out with shake-table tests to investigate the displacement capacity of shear-dominated reinforced masonry wall systems. This paper presents results of the first shake-table test conducted in this project on a full-scale single-story coupled T-wall system. The structure was tested to a drift ratio exceeding 15% without collapse. 

Since its commissioning in 2004, the UC San Diego Large High-Performance Outdoor Shake Table (LHPOST) has enabled the seismic testing of large structural, geostructural and soil-foundation-structural systems, with its ability to accurately reproduce far- and near-field ground motions. Thirty-four (34) landmark projects were conducted on the LHPOST as a national shared-use equipment facility part of the National Science Foundation (NSF) Network for Earthquake Engineering Simulation (NEES) and currently Natural Hazards Engineering Research Infrastructure (NHERI) programs, and an ISO/IEC Standard 17025:2005 accredited facility. The tallest structures ever tested on a shake table were conducted on the LHPOST, free from height restrictions. Experiments using the LHPOST generate essential knowledge that has greatly advanced seismic design practice and response predictive capabilities for structural, geostructural, and non-structural systems, leading to improved earthquake safety in the community overall. Indeed, the ability to test full-size structures has made it possible to physically validate the seismic performance of various systems that previously could only be studied at reduced scale or with computer models. However, the LHPOST's limitation of 1-DOF (uni-directional) input motion prevented the investigation of important aspects of the seismic response of 3-D structural systems. The LHPOST was originally conceived as a six degrees-of-freedom (6-DOF) shake table but built as a single degree-of-freedom (1-DOF) system due to budget limitations. The LHPOST is currently being upgraded to 6-DOF capabilities. The 6-DOF upgraded LHPOST (LHPOST6) will create a unique, large-scale, high-performance, experimental research facility that will enable research for the advancement of the science, technology, and practice in earthquake engineering. Testing of infrastructure at large scale under realistic multi-DOF seismic excitation is essential to fully understand the seismic response behavior of civil infrastructure systems. The upgraded 6-DOF capabilities will enable the development, calibration, and validation of predictive high-fidelity mathematical/computational models, and verifying effective methods for earthquake disaster mitigation and prevention. Research conducted using the LHPOST6 will improve design codes and construction standards and develop accurate decision-making tools necessary to build and maintain sustainable and disaster-resilient communities. Moreover, it will support the advancement of new and innovative materials, manufacturing methods, detailing, earthquake protective systems, seismic retrofit methods, and construction methods. This paper will provide a brief overview of the 1-DOF LHPOST and the impact of some past landmark projects. It will also describe the upgrade to 6-DOF and the new seismic research and testing that the LHPOST6 facility will enable.