DAMAGE EVALUATION BY NONLINEAR 3D ANALYSIS ON RC UNDERGROUND STRUCTURE SUBJECTED TO FAULT DISPLACEMENT

Abstract

 A damage evaluation method is proposed based on applying a damage index according to required performance of a structure. This method evaluates three-dimensionally complicated damage to the structure generated by a fault displacement. In this study, targeted structure is an underground RC box culvert, which has a surrounding backfill and is founded on bedrock in nuclear power plants.

 The selection of the damage index applicable to the damage evaluation and the threshold value depending on the damage state are examined based on the loading experiment results of the 1/4 scaled model of box culvert with two tunnels. The damage index is selected according to the required performance (water flow performance, support performance, water storage performance) of the culvert. In particular, for tensile damage, a new threshold value is proposed by comparing the damage condition and the damage index in the loading experiment.

 Furthermore, the deformation and damage modes of the culvert under the effect of various fault displacement conditions are analyzed by three-dimensional coupled non-linear analysis of the real scale model, with consideration of the ground fracture condition and the ground-structure interaction.

 Consequently, an example of the results obtained by the damage evaluation method for the fault displacement is provided. In conclusion, the damage mode of the structure is understood in detail by applying the selected damage index and evaluating the damage with the threshold value.