Influence of mechanical parameters on non-linear static analysis of masonry buildings: a relevant case-study

This paper focuses on the dynamic behaviour of a low-rise masonry building representing the Italian residential heritage through experimental and numerical analyses. The authors discuss an application of combined Operational Modal Analysis and Finite Element Model updating for indirect estimation of the structural parameters. Two ambient vibration tests were carried out to estimate the structure’s dynamic behaviour in operational conditions. The first experimental setup consisted of accelerometers gathered in a row along the first floor to characterize the local dynamic of the floor. Conversely, the second setup had the accelerometers placed at the building’s corners to characterize the global dynamics. The outcomes of the first setup were used to estimate the mechanical parameters of the floor, while the ones form the second were used to characterize the mechanical parameters of the masonry piers. Therefore, two finite element models were implemented: (i) a single beam with an equivalent section of the floor to grasp the local behaviour of the investigated horizontal structure; (ii) an equivalent frame model of the entire building to characterise the global dynamic behaviour. The model updating process was developed in two phases to seize local and global dynamic responses. The updated numerical model formed the basis for a sensitivity analysis using the modelling parameters. The authors chose to delve into the influence of the floor on the dynamic behaviour of low-rise masonry buildings. With this aim, non-linear dynamic analyses were carried out under different mechanical characteristics of floors, expressing the scatter for ordinary masonry buildings. The displacements’ trends along the height of the building evidenced the notable role of the floor’s stiffness in the non-linear dynamic behaviour of the building. Lastly, the authors derived the fragility curves predicting the seismic performance in failure probability under a highly severe damage state.

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Response Reduction Factor for Lateral Load Resisting Frames with Vertical Discontinuity of Asymmetrical Structure

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1197/1/012005 ◽

2021 ◽

Vol 1197 (1) ◽

pp. 012005

Author(s):

Trupti Dongare ◽

Preeti Kulkarni

Keyword(s):

Static Analysis ◽

Reduction Factor ◽

Soil Conditions ◽

Response Reduction Factor ◽

R Factor ◽

Lateral Forces ◽

Asymmetrical Structure ◽

Non Linear ◽

Wall System ◽

Linear Static Analysis

Abstract In recent times, the RC building construction with vertical discontinuity that is floating column structures are unavoidable feature and increases trends day by day. To reduce lateral forces the earthquake resistance structures are designed so the response reduction factor (R) is used to determine these lateral forces by using base shear values. The R factor depends upon the overstrength factor, ductility factor, redundancy factor also the sizes of columns, types of soil, zones and load transferring path, etc. The IS code provides response reduction factor only for OMRF and SMRF along with other structures like Braced frame system, Structural wall system, Dual system, Flat slab structure wall system, etc. so there are no codal provisions for floating column structures. Thus it is essential to study the real behaviours of RC buildings with discontinuity in load transferring path through non-linear static analysis, so the present research work is done on trying to find R factor for vertical discontinuous asymmetrical structure for different soil conditions and different positions of floating column using moment resisting frames. And the structure is analyzed by response spectrum analysis and non-linear static analysis using SAP2000 software.

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