### Quasi-Static Tests on Masonry Panels  
In order to evaluate the mechanical properties, load-bearing capacity, and failure mechanisms of masonry wall systems, a comprehensive series of quasi-static tests was conducted on two types of masonry configurations. The experimental program comprised two groups of six wall specimens each, constructed using cement-lime mortar. The first group consisted of walls made from **hollow-clay masonry units**, while the second group utilized **solid-clay brick masonry**. Prior to analytical modeling, all twelve wall specimens were constructed under controlled laboratory conditions at the Dynamic Testing Laboratory of the Institute of Earthquake Engineering and Engineering Seismology (IZIIS), as illustrated in Figure 3. The quasi-static testing methodology offered a key advantage: it enabled high-precision control of loading protocols and allowed for detailed observation and documentation of damage evolution, crack propagation, and failure modes. However, a recognized limitation of this testing approach is the **absence of dynamic loading effects**, which are critical to replicating the inertial forces and strain-rate-dependent responses typical of real seismic events. Despite this constraint, the experimental campaign provided essential insights into the in-plane behavior of masonry wall assemblies and served as a foundational step for subsequent analytical and numerical modeling. Based on the carried out experimental quasi-static tests on wall elements performed at IZIIS Lab, the following is concluded:  
Figure 3: Wall elements for quasi-static testing [33]. The average characteristics compressive strength of the hollow-clay masonry units was 1.50 MPa and average characteristics tensile and shear strength were 0.05 MPa and 0.08 MPa, accordingly. These results from these quasi-static tests are prerequisite for correct further analysis of the scaled model as well as for interpretation of the model behavior. **Characteristics of masonry panels**  
Two basic types of wall element built from hollow-clay were tested in the considered case (Table 1). Two distinct testing protocols were employed to characterize the mechanical response of the masonry wall specimens. The first set of specimens was subjected to uniaxial compressive loading to evaluate their behavior under axial stress conditions (Figure 4). The second set underwent diagonal compression testing, commonly referred to as the shear or diagonal tensile test, to assess the in-plane shear capacity and failure modes (Figure 5). All tests were conducted either until the onset of cracking or the complete failure of the specimen, depending on the observed behavior. In addition to the applied axial or diagonal force, the displacement of the loading actuator in the direction of force application was continuously monitored. A comprehensive instrumentation setup was implemented to capture all relevant response parameters, including force-displacement relationships, crack initiation points, and deformation patterns, ensuring accurate and detailed characterization of the mechanical performance of the tested masonry assemblies. **Instrumentation**  
Instrumentation of the masonry wall specimens was designed and implemented in alignment with the specific objectives and testing protocols of the experimental program. A dedicated load cell was employed to measure the applied axial or diagonal force, while multiple channels were allocated to record relative displacements using Linear Variable Differential Transformers (LVDTs) positioned at strategically selected locations on each specimen. This configuration enabled the acquisition of detailed displacement profiles and provided insight into the deformation behavior and crack development of the wall elements under loading. The relative displacements recorded at characteristic points facilitated the experimental determination of key strength parameters and stiffness properties of the masonry assemblies.