###### Abstract  
For the past few decades, during each disastrous earthquake, severe damage and poor seismic performance of masonry infilled RC frames, including many newly designed ones, have been reported extensively. Inherent problems related to analysis and design methods for tight-fit infilled frame structures have not yet been solved and are recognized as being far from satisfactory in terms of completeness and reliability. The primary objective of this research was to propose and test an innovative method that can effectively mitigate undesirable interaction damage to masonry infilled RC frame structures. This proposed technical solution consists of connection of the infill panel to the bounding columns with steel reinforcement connections deployed in mortar layers and anchored to the columns. This is practical, cheap and easy to implement without any specific technology, which is especially important for developing countries. A three story, two bay RC building model with the proposed connection implemented on the infill walls was designed and tested on the shake table at IZIIS in Skopje, N. Macedonia. The test results and design guidelines/recommendations from the proposed research are also expected to benefit the infrastructural development in other countries threatened by earthquakes, preferably in the Balkan and the Mediterranean region. m achemic definition  
A substantial body of experimental and numerical research [1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27] has demonstrated that unreinforced masonry infill walls significantly influence the seismic behavior of RC frames. Due to their inherent in-plane stiffness and strength, these panels act as unintended diagonal compression struts under lateral loading, substantially modifying the lateral load distribution, stiffness, and failure mechanisms of the host structure. This infill-frame interaction may result in stress concentrations, shear failures, and the formation of weak or soft stories, particularly in structures lacking proper seismic detailing. These adverse effects are especially pronounced in non-seismically designed frames, where the irregular distribution of infills across stories further exacerbates lateral deformation demands. Moreover, the out-of-plane behavior of masonry infill panels is a critical factor often overlooked in both analysis and design [28]. During seismic events, infills are simultaneously subjected to in-plane packing forces and out-of-plane inertial forces, leading to complex stress states and potential for out-of-plane instability. Empirical studies [29; 30; 31] have shown that panels with insufficient anchorage to surrounding frames are particularly susceptible to detachment or collapse, posing severe safety hazards to occupants and bystanders. This vulnerability was starkly demonstrated during the 2023 Kahramanmaras earthquake sequence in Turkiye, which included two major mainshocks of Mw 7.7 and Mw 7.6 occurring within hours of each other. Post-earthquake reconnaissance efforts documented extensive damage to RC frame structures with URM infills throughout affected cities such as Kahramanmaras, Hatay, Gaziantep, and Adhyaman. Observed failure modes included diagonal cracking, corner crushing, and disintegration of infill panels, with many cases of partial or complete out-of-plane collapse. In particular, buildings with open ground stories or irregular infill distribution experienced severe soft-story mechanisms, leading to collapse. These findings are consistent with previous seismic events--such as the 1999 Kocaeli (Turkiye), 2008 Wenchuan (China), presented in Figure 1, 2010 Maule (Chile), 2009 L'Aquila, and 2016 Central Italy earthquakes--where infill-related failures significantly contributed to structural damage and life loss. In addition to complete collapses, a considerable number of otherwise structurally intact RC frames experienced infill panel dislodement and detachment during the Kahramanmaras events.