Condition assessment of timber beam in a typical Tibetan heritage building under crowd load

Abstract

Many Tibetan heritage buildings in China are opened to tourists recently. The crowd load has become a significantly concern to the structural safety of the structures. The beams of these wooden structures are easily deformed or cracked under the crowd load. The condition assessment of the timber beam in a Tibetan heritage building under crowd load has become a new challenge. Convention statistical evaluation method making use of monitored strain data require a threshold value which is determined with no physical meaning. This paper separates the monitored strain into temperature-induced strain and crowd-induced strain. An analytical model of the timber beam including the semi-rigid connections at its ends is formulated for the calculation of different material stresses under crowd load. The condition of the beam is then quantitatively evaluated against the residual strength of material. The shear stress at any point of the beam can then be calculated from limited number of sensors for evaluating the more popular shear crack damage which is not monitored in most existing ancient structures.