S04 398: FEA OF MASONRY BUILDINGS BY MEANS OF A NEW OPTIMISED INDIRECT NLTH METHOD

 

A.A. van den Bos1 and A. Garofano2
1)   DIANA FEA
Arnhem, Netherlands
e-mail: a.vandenbos@dianafea.com
2)  DIANA FEA
Delft, Netherlands
e-mail: a.garofano@dianafea.com

Keywords: DIANA FEA; Masonry; Earthquake; NLTH, Indirect method.

Abstract. Finite Element Analysis (FEA) represents a powerful tool for assessing the behaviour of masonry buildings during earthquake loading. A 3D Non-Linear Time History (NLTH) gives the most advanced results, being a time-domain analysis and allowing consideration of all possible sources of non-linearity characterizing the behaviour of a masonry structure. Therefore, the full (non-linear) structural interaction can be taken into account, including the Soil Structure Interaction (SSI) and foundation behaviour.
In earthquake prone regions sometimes, a large amount of structures has to be checked against newly released earthquake signals. Existing structures need to be analysed and maybe strengthened. Therefore, the computing time for carrying out a NLTH analysis can become too large. Based on the existing linear indirect method, DIANA promotes a non-linear variant of the indirect soil method.
In this study, we perform a NLTH with the indirect approach. A full model with non-linear soil and foundation is analysed based on an optimised method. In the described procedure, all the forces obtained from a first (full-model) calculation are taken from the top of the foundation level and processed as input forces for a second (superstructure-only) non-linear structural analysis without soil and foundation.
A typical Dutch masonry building is analysed in a 3D Non-Linear Time History (NLTH) input. The building is analysed with the use of the new engineering masonry material, which includes hysteretic behaviour in tension, compression and shear loading.
The paper includes aspects on the description of the indirect method and its optimization, the new masonry material model available in DIANA [1], and the checking features to process building checks and strengthening methods in a much faster and efficient way.