# Development of a System for Cyclic Shear Tests on Full-Scale Walls
## 3 Test Setup Description
### Load Transfer Subsystem  
This subsystem comprises the following elements (and their respective functions): main beam (transferring displacements from the actuator to the other passive loading elements), hinges (allowing rotations and then increasing the system's degree of freedom), and other high resistance metallic elements (transferring forces and displacements to the wall specimens). To obtain the horizontal forces and displacements at the top of the wall (the main objective of the cyclic shear test), a load cell with a capacity of 100 kN was inserted between the hinge and the wall. Although the load is applied at the confinement devices plates, which transfer it to the concrete beam's surface in a distributed manner, it is registered as a concentrated load as the cell is located at the load axis. The displacement  
Figure 12: (**a**) Counterweight support rod. (**b,c**) Lateral support rollers. transducers were fixed in an external rigid aluminum structure independent of the specimen and to the concrete footing foundation of the specimens. As already mentioned, the purpose of the hinges was to allow the system to operate with a greater number of degrees of freedom and then reduce the interference of forces and moments at the specimens and prevent movement incompatibilities due to displacement restrictions. Thus, hinges were installed at three points (Figure 13): the connection between the actuator and the wall, the connection between the actuator and the main test beam, and the connection between the wall and the vertical transition element (steel triangle). While the first two hinges provide the possibility of rotation on the main test beam and thus reduce the vertical forces on the wall and the load cell, the hinge next to the specimen allows the wall rotations to occur relatively independently of the rotations of the load cell, as the transfer of momentum from the test system to the wall is prevented. The main test beam comprised stiffened H 300 \(\times\) 300 steel pieces with high flexural and torsion rigidity. These elements allowed the system to function within the test plan, together with the displacement restriction devices positioned on the gantry and the support rod (Figure 14). This beam, for which the axis was aligned with the reaction wall and with the servo-actuator axes, was leveled before connecting the test system to the specimen and was positioned at an elevation of about 60 cm above the top of the walls, so as not to interfere with the other walls built on the same footing. As the main beam had holes every 8 cm, a set of transition elements was installed between the main beam and the wall to be tested (Figure 15). These elements were connected to the lower table of the main beam and descended vertically until it was possible  
Figure 14: Main test beam. Figure 13: Details of the hinges positioned before the servo-actuator (**a**), after the servo-actuator (**b**), and next to the specimen (**c**). to apply the load at an approximate height of 2.20 m from the footings (in the direction of the middle horizontal section of the reinforced concrete beam built at the top of the wall). The counterweight calibration was performed after installing the transition elements and before connecting the test system to the specimen. The load application point was in line with the geometric center of the wall cross-section, aiming to portray the closest behavior in a seismic context, in which the forces mobilize the vertical axis that passes through the centers of mass of the rows, considered as a homogeneous material. Adjustments for applying loads at the desired point and eliminating gaps between the test system and the specimens located in different positions on the footings were achieved through the following mechanisms:  
* Position adjustments along the main test axis.