COMPREHENSIVE STRUCTURAL-MECHANICAL AND REGULATORY ANALYSIS OF THE SEISMIC RESISTANCE OF VERNACULAR ARCHITECTURE IN UZBEKISTAN: TRIBOLOGY OF THE SINCH AND PAKHSA SYSTEMS

Abstract

Uzbekistan occupies a seismically hazardous territory shaped by the long-term collision of the Indian and Eurasian lithospheric plates and governed by the active Tien Shan and Pamir-Alai seismogenic systems. This research presents an IMRAD-adapted English version of a comprehensive analytical paper on the seismic performance of local architecture in Uzbekistan, with specific focus on two historically significant structural systems: monolithic earthen *pakhsa* and timber-framed *sinch*. The study incorporates historical evidence from major earthquakes, including the 1966 Tashkent earthquake and the 1976–1984 Gazli earthquake sequence, with cadastral and GIS-based housing figures, vulnerability matrices, structural-mechanical interpretation, and an assessment of the progression of seismic codes. The findings indicate that *pakhsa* buildings, despite their historical low cost and ecological merits, behave as massive and rigid monoliths with minimal tensile capacity, weak shear resistance, and high propensity for out-of-plane failure. Conversely, *sinch* systems display distinctly better seismic response owing to distributed friction, localized impact absorption, semi-ductile joint pivots, and stiffness decay that extends the structural duration and lessens inertial requirement. Vulnerability matrices for individual housing types confirm that at intensities of 8 points on the MSK-64 scale, *pakhsa* and adobe structures tend toward collapse states, whereas *sinch* buildings generally maintain structural soundness with minor to moderate degradation. The study contends that the main practical objective for Uzbekistan is not the abandonment of indigenous materials as such, but the formalization of friction-based, energy-dissipative structural concepts, coupled with cost-effective upgrading techniques and hybrid design approaches for low-rise dwellings in seismically active zones.