Conservation, strengthening and restoration of Architectural Heritage require first of all a full understanding of the structural behaviour, of the materials characteristics and of the causes of decay and damage. Then safety levels can be evaluated and remedial measures decided.
Unfortunately these operations can't be based only on objective evaluations and mathematical analysis, due to the difficulties to have reliable data and to reduce the complexity of the reality and of the phenomena to semplified schemes; it is necessary, therefore, that those quantitative analysis would be associated with qualitative ones, based on the direct observation of the structural damage and materials decay, on the historical survey, etc., all of which makes very difficult to establish rules and codes in a traditional way: standards, guidelines, or recommendations, should trace out more a coherent methodology than mathematical rules.
An “explanatory report”, where all the different phases of the study are shown, may help to give scientific value to all the process.
In the paper are described three studies - the pyramid of Chephen in Egypt, the Colosseum in Rome and the temples of Angkor in Cambodia - to show how it would be difficult to understand their structural behaviour and to take appropriate decisions just following traditional mathematical methods; it is integrating these structural analyses with the qualitative information resulting from the historical research and the careful observation of the monument that a scientific approach can be laid down.