A simplified analytical method for earthquake-induced bending failure of hollow-core polygonal masonry pagodas

Abstract

Hollow-core polygonal masonry pagodas are vulnerable to seismic bending failure along inter-story or near-inter-story sections, yet simplified methods for identifying governing fracture interfaces and evaluating cumulative cracking are limited. This study develops a simplified variable-cross-section cantilever model considering geometric tapering, hollow-core, and height-dependent seismic amplification. Unidirectional seismic response and the El Centro record are assumed. The governing interface is identified using maximum tensile stress, and cumulative cracking using fracture energy and a safety factor. Application to a seven-story octagonal hollow-core pagoda locates the governing interface at the bottom of the second story, consistent with previous numerical and experimental observations. Seismic acceleration, superstructure mass, and hollow-core geometry primarily control cumulative cracking, while increasing masonry elastic modulus provides limited mitigation under strong earthquakes. The method suits preliminary screening of vulnerable interfaces in hollow-core polygonal masonry pagodas with few openings, but not rectangular-section pagodas or refined analyses involving fatigue and nonlinear cyclic damage.