Assessment of Seismic Damage in Nativity Church in Bethlehem Using Pushover Analysis

Abstract

This study focuses on advanced finite element (FE) analyses on The Church of Nativity located in Bethlehem (Palestine), one of the most historic structures in the world. To ensure the model quality, a 3D FE model was created using two types of typical commercial software, DIANA FEA and SAP2000. From analyses, one of the expected behaviors for this kind of masonry structure “low modal period” was found. The seismic behavior of the church was studied using pushover analyses, which were conducted using DIANA FEA. The first unidirectional mass proportional load pattern was created in both directions, X-direction as a longitudinal direction and Y-direction as the transversal direction. An incremental iterative procedure was used with monotonically increasing horizontal loads, using constant gravity loads. The results showed that the transversal direction is the most vulnerable and the damage concentrates at the main lateral (longitudinal) walls, mainly at the south and north alignment walls, and also at the vaults and at the connections of the vaults to the apse. Crack width was at the upper limit in the in-plane direction (X-direction). While, in Y-direction, it exceeded the limits of IBC code in width and length with a maximum width of 13.7 mm. A more accurate nonlinear dynamic analysis is recommended in the near future, which takes into account the material nonlinearity for more reasonable seismic behavior simulation.