Guide for the Structural Rehabilitation of Heritage ... - Test Input

a) With gypsum ‘tell-tales’ (21) b) With displacement transducers (3)Figure 19: Monitoring of cracks in buildingsBecause the installation of a monitoring system in the building is, in general, very expensive,it should be the object of a cost-benefit analysis and only the information relevant to theevolution of the phenomena will be registered. The subsequent treatment of the informationthat is being acquired should also be assured.3.7 Elaboration of the diagnosisThe diagnosis of the situation in the building is the process of identifying or determining thenature and the cause of the defects in the building.The diagnosis is a very delicate task, because the available data refers to the effects(symptoms), while the causes that are their origin (or, as it usually happens, the severalconcomitant causes) are what need to be identified. Intuition and experience are essentialcomponents of the diagnosis.On figure 20 a flowchart of the actions to be undertaken in the elaboration of the diagnosis ispresented.For the elaboration of the diagnosis, an interpretative model (scenario) that interprets theexisting defects in the building will be established, based on the results of preliminaryinspection. When that information is not sufficient, it has to be complemented by a detailedinspection, and, eventually, by the modelling of the building.On this modelling, usually, simplified models are used, but, in some circumstances,sophisticated models may be needed (see, section 4). The properties of the building materialsand the values of the actions to be adopted on this modelling will be the nominal ones,obtained directly from the tests or from the field measurements, without using any safetycoefficients).24/48