Three-dimensional limit analysis of ancient masonry buildings with rigid block models

2010 ◽

Vol 133-134 ◽

pp. 653-658

Author(s):

Seyed Rohollah Pashanejati ◽

Climent Molins

Keyword(s):

Limit Analysis ◽

Safety Assessment ◽

Failure Mechanisms ◽

Three Dimensional ◽

Masonry Buildings ◽

Seismic Safety ◽

Early 19Th Century ◽

Analysis And Design ◽

Macro Block ◽

Kinematic Limit

This paper presents an investigation about the capabilities of simplified kinematic limit analysis for the safety evaluation and for the design of strengthening of masonry historical buildings. Limit analysis allows, with a reduced number of mechanical properties and for a given ultimate condition of the structure, affordable safety analysis and design of strengthening to the practitioners. Masonry buildings subjected to earthquake show in most cases local failure mechanisms rather than global failure mechanisms due to the lack of integrity of structure. For this reason, simplified kinematic limit analysis has been accepted as a method to design the strengthening of masonry buildings, according to the Italian Ordinance (O.P.C.M. 3431). To validate the applicability of this method, its results had been compared with those provided by three dimensional macro block limit analysis (Bustamante, 2003) for the Via Arizzi house. It is worth noting that results of simplified kinematic limit analysis provided similar results as those achieved by 3D macro block. Also this method was implemented to seismic safety assessment of Tekyeh Amir Chakhmagh in Iran based on the results obtained for the out of plane and in plane behaviour of walls. Tekyeh Amir Chakhmagh is an early 19th century tiled edifice that was built to serve as grand-stand for watching religious rites and also provided an imposing entrance to Amir Chakhmagh bazaar. This stunning three-story facade of the building is one of the most recognizable and unusual buildings in Iran.

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Three-Dimensional Limit Analysis of Dry-Joint Masonry Walls using Rigid Block Modelling

Proceedings of the Fourteenth International Conference on Civil, Structural and Environmental Engineering Computing ◽

10.4203/ccp.102.73 ◽

2013 ◽

Author(s):

F. Portioli ◽

C. Casapulla ◽

L. Cascini ◽

R. Landolfo

Keyword(s):

Limit Analysis ◽

Three Dimensional ◽

Masonry Walls ◽

Rigid Block

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Force-Based Seismic Evaluation of Retrofitting Interventions of Historic Masonry Castles by 3D Rigid Block Limit Analysis

Applied Sciences ◽

10.3390/app10155035 ◽

2020 ◽

Vol 10 (15) ◽

pp. 5035

Author(s):

Lucrezia Cascini ◽

Giuseppe Brando ◽

Francesco P. A. Portioli ◽

Morena Rita Forgione ◽

Claudio Mazzanti ◽

...

Keyword(s):

Limit Analysis ◽

Failure Modes ◽

Three Dimensional ◽

Historical Analysis ◽

Quantitative Measure ◽

Rigid Block ◽

Seismic Evaluation ◽

Seismic Capacity ◽

Seismic Safety ◽

Historic Masonry

This paper deals with the force-based assessment of collapse mechanisms and strengthening interventions of the historic masonry castle “Bussi sul Tirino” (Abruzzi, Italy) using rigid block limit analysis (RBLA). The structure, which is a fortified palace dating back to the 11th century, has experienced severe earthquakes over the centuries and was hit once again in 2009 by the L’Aquila earthquake. Based on the historical analysis and the results of in situ investigations, a spatial rigid block model of an entire structural unit was generated using the in-house software LiABlock_3D. The software is a MATLAB® based tool for three-dimensional RBLA, which provides as outputs collapse failure modes and collapse load multipliers. In addition, a specific routine was developed for the purpose of the study to compute the participating mass ratio and the spectral acceleration that activated the failure mechanisms. The results of the numerical analysis were used to address three different retrofitting interventions, based on the use of connection elements and ties that, according to the minimum intervention principle, progressively enhanced the seismic capacity. Comparisons in terms of seismic safety indices are finally provided in order to give a quantitative measure of the effectiveness of the adopted retrofitting strategies.

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Application of a Three-Dimensional Rigid Block Model to the Limit Analysis of Large Scale Masonry Panels

Proceedings of the Twelfth International Conference on Computational Structures Technology ◽

10.4203/ccp.106.76 ◽

2014 ◽

Author(s):

F. Portioli ◽

C. Casapulla ◽

L. Cascini

Keyword(s):

Limit Analysis ◽

Large Scale ◽

Three Dimensional ◽

Rigid Block ◽

Block Model

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Three-dimensional face stability analysis of shallow tunnels using numerical limit analysis and material point method

Tunnelling and Underground Space Technology ◽

10.1016/j.tust.2021.103904 ◽

2021 ◽

Vol 112 ◽

pp. 103904

Author(s):

Fabricio Fernández ◽

Jhonatan E.G. Rojas ◽

Eurípedes A. Vargas ◽

Raquel Q. Velloso ◽

Daniel Dias

Keyword(s):

Stability Analysis ◽

Limit Analysis ◽

Three Dimensional ◽

Material Point Method ◽

Material Point ◽

Point Method ◽

Face Stability ◽

Shallow Tunnels ◽

Dimensional Face

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Hydrogen Mixing Analyses for a VVER Containment

10th International Conference on Nuclear Engineering, Volume 2 ◽

10.1115/icone10-22206 ◽

2002 ◽

Cited By ~ 2

Author(s):

Pal Kostka ◽

Zsolt Techy ◽

James J. Sienicki

Keyword(s):

Three Dimensional ◽

Primary System ◽

Hydrogen Distribution ◽

Lumped Parameter ◽

Circulation Patterns ◽

Contour Plots ◽

Design Basis Accident ◽

Input Model ◽

Block Models ◽

Containment Integrity

Hydrogen combustion may represent a threat to containment integrity in a VVER-440/213 plant owing to the combination of high pressure and high temperature. A study has been carried out using the GASFLOW 2.1 three-dimensional CFD code to evaluate the hydrogen distribution in the containment during a beyond design basis accident. The VVER-440/213 containment input model consists of two 3D blocks connected via one-dimensional (1D) ducts. One 3D block contains the reactor building and the accident localization tower with the suppression pools. Another 3D block models the air traps. 1D ducts represent the check valves connecting the accident localization tower with the air traps. The VVER pressure suppression system, called “bubbler condenser,” was modeled as a distributed heat sink with water thermodynamic properties. This model accounts for the energy balance. However, it is not currently possible to model dynamic phenomena associated with the water pools (e.g., vent clearing, level change). The GASFLOW 2.1 calculation gave detailed results for the spatial distribution of thermal-hydraulic parameters and gas concentrations. The range and trend of the parameters are reasonable and valuable. There are particularly interesting circulation patterns around the steam generators, in the bubbler tower and other primary system compartments. In case of the bubbler tower, concentration and temperature contour plots show an inhomogeneous distribution along the height and width, changing during the accident. Hydrogen concentrations also vary within primary system compartments displaying lower as well as higher (up to 13–20% and higher) values in some nodes. Prediction of such concentration distributions was not previously possible with lumped parameter codes. GASFLOW 2.1 calculations were compared with CONTAIN 1.2 (lumped parameter code) results. Apart from the qualitatively similar trends, there are, for the time being, quantitative differences between the results concerning, for example, pressure histories, or the total amount of steam available in the containment. The results confirm the importance of detailed modeling of the containment, as well as of the bubbler condenser and sump water pools. The study showed that modeling of hydrogen distribution in the VVER-440/213 containment was possible using the GASFLOW 2.1 code with reasonable results and remarkable physical insights.

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