Digital tool could help save historic stone buildings

Researchers at the University of Sheffield have developed open-source software that could allow the safety of stone and brick masonry constructions to be assessed using a new engineering technique.

Thrust layout optimisation (TLO) builds on the thrust line method that engineers have used since the late 1600s to assess the safety of masonry buildings and bridges.

The researchers explain in a paper, published by The Royal Society, how TLO is more accurate and reliable than the traditional method developed by Robert Hooke in 1675. it also addresses its limitations, such as ignoring the possibility of failure due to sliding.

Lead author and researcher at the University of Sheffield, Isuru Nanayakkara, said that a renewed interest in the use of stone in construction  - a low embodied carbon material - will need suitable digital analysis and design tools.

Nanayakkara said: "Currently, engineers have been turning to analysis and design tools that are better suited for steel and concrete structures, which means that steel reinforcement is sometimes being used in new masonry designs when it's not needed."

To enable two-dimensional mesh geometrics created in CAD environment to be efficiently converted into an appropriate data structure for use with the TLO procedure, a suitable digital workflow was developed. The Rhino software package was used to prepare the test examples, with an export process developed to transfer vertex and face data. The TLO procedure was implemented as a Python script.

For data handling, a hybrid data structure was created to facilitate storing of information and performing operations on geometric data through vertices, edges, faces and links. The open-source half-edge data structure OpenMesh was used for the management of vertices, edges and faces, and NetworkX was used for handling link connectivity.

Professor Matthew Gilbert, Professor of Civil Engineering at the University of Sheffield, added: “A long-running problem is that the ways in which applied forces are successfully transmitted down to the ground in masonry structures are often not intuitively obvious, so digital tools that help explain this to engineers are potentially invaluable.

“The current climate crisis also makes it particularly important that engineers have access to efficient and reliable tools to assess the safety of existing masonry constructions – helping to ensure that these can be used long into the future, rather than being needlessly demolished and replaced.”

This article first appeared on Construction Manager