Design, analysis and construction of hydrostatic masonry bridges: An assessment of load capacity using the discrete element method and physical scale models
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Structural engineering and building technology (MPSEB), MSc
Publicerad
2024
Författare
Forsberg, Jacob
Svedjer, Emil
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Masonry is a building technique extensively used throughout history in different
applications. However, structures in concrete have become common practice during
the last century. Even though masonry bridges cover a large portion of existing
bridges, and are a sustainable choice because of their adaptability and long service
life, sufficient methods to assess and design masonry bridges are not clear.
In this master thesis, the collapse load of masonry bridges designed as hydrostatic
shells is investigated. The methods used are hand calculations, load tests on phys ical scale models and computational analysis using the Discrete Element Method
(DEM). To validate the computational method an analysis is performed on a simple
masonry arch as it is a known case. To validate the computational method, an
analysis is performed on a simple masonry arch, a well-documented case, thereby
obtaining useful coefficients for the unproven concept of the hydrostatic bridge.
The form finding process is done in Rhinoceros3D and Grasshopper, and the geom etry created is used to model both the Discrete Element Model and the physical
model.
The hand calculations provided highly conservative results, as the resulting collapse
load from the DEM analysis is 66 times larger and from the physical load test
six times larger. The computational and physical models behave similarly when
loaded, and both indicate that the critical loading position is in the midspan of the
bridge. The physical model was loaded with 13.9 kg before collapse. By applying
dimensional scaling, this result translates to 46.9 tonnes for a full-scale bridge. This
indicates that the bridge concept is viable at full-scale. The result from the DEM analysis is qualitatively good but over-estimates the collapse load.
Further work includes adding features to the computational model to provide more
reliable results and investigating different geometries for the hydrostatic bridge.
Beskrivning
Ämne/nyckelord
masonry bridges, form finding, discrete element method, masonry shells, physical bridge models, hydrostatic shell