Seismic performance of a historic timber structure on a slope

Abstract

In southwest China, a seismically active zone, most of the historic timber buildings are built on slopes. To ensure the structural safety of these heritage buildings, this study aims to determine the dynamic characteristics of a typical historic timber building on a slope and investigate further its seismic performance using the multi-scale model based on the principle of equal work done. The in-situ dynamic test revealed that the first and fourth-order frequencies of the Erwang temple range from 3.079 Hz to 11.265 Hz, and the first and third-order mode shapes are translational along the perpendicular to the slope direction and along the slope direction, respectively. The time-history analysis of the Erwang multi-scale model indicates that the area of interaction between the tenon and mortise exhibits plastic behavior and that the irrecoverable deformation in the tenon is more severe, while the column and beam remain in the elasticity. The irregularity in the heights of the columns causes an abrupt change in the inter-storey drift angle in the third floor along the slope, and the base shear force value of the column foot in the upper embedding end is the largest. The maximum value of the inter-storey torsion angle of the Erwang temple is found at the upper embedding storey. Therefore, the upper storeys of the building is its weakest region and should be given priority in seismic strengthening.