In this study, a semi-active structural vibration control is employed, combining an optimally tuned mass damper (TMD) installed at the roof and a magnetorheological (MR) damper with a fuzzy decision-making system placed between the foundation and the first floor, to control the vibrations of seven- and twelve-story steel structures. To evaluate the proposed control system and the influence of different soil types beneath the foundation, three soil categories soft, medium, and stiff are considered, taking into account soil-structure interaction (SSI). The performance of the control system for the considered soil types is assessed under seven seismic excitations with peak accelerations ranging from 0.1g to 1.0g in increments of 0.1g. Nonlinear models of the seven- and twelve-story structures are developed in OpenSEES, while the fuzzy decision-making system is implemented in MATLAB; a TCP/IP-based network interface is used to establish communication between the two software platforms. Results from incremental dynamic analyses indicate that for the seven-story structure equipped with a TMD, roof displacement and RMS response improved by 5.6% and 13.4%, respectively, compared to the uncontrolled case; corresponding improvements for the twelve-story structure were 8.5% and 16.6%. When combining TMD and MR dampers while considering SSI, for soft, medium, and stiff soils, the roof displacement and RMS in the seven-story structure im-proved to (11.85%, 12.66%), (11.84%, 11.55%), and (11.93%, 11.72%), respectively, com-pared to the TMD-only case. For the twelve-story structure, the corresponding values were (10.60%, 13.36%), (9.31%, 9.89%), and (9.38%, 9.15%). These results demonstrate the effective performance of the proposed control system.