Field test and emergency reinforcement evaluation for an ancient wood pagoda

Abstract

Ancient wood pagodas, as the excellent representative of ancient China, play an important role in Chinese historical, art, and scientific aspects. Because most pagodas are lacking maintenance for a long time and the long term reinforcement measure has not been determined, it is necessary to carry out an emergency reinforcement method to avoid further damage. This paper presents a design guideline of emergency reinforcement method for ancient wood pagodas. Field tests based on pulsating method were carried out to identify the dynamic characteristics, structural stiffness, and structural damages. The modal frequency, modal shape of different columns and stiffness of each story indicate that the second apparent story is the weak point of the whole structure. To effectively analyze the nonlinear performance of the second apparent story and verify the superiority of the emergency reinforcement method, three elaborated finite element models of the second apparent story in undamaged, and current and reinforced states are established. The buckling analysis shows that the emergency reinforcement method could improve the critical load 89% nearby compared with the current structure. In addition, the seismic analysis proves that the emergency reinforcement method has positive effects on strengthening the weak point to against the earthquakes.