PSI - Issue 78

Marco Nale et al. / Procedia Structural Integrity 78 (2026) 1095–1102

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2.2. Control levels definition

Based on the definition of the acceleration thresholds, the corresponding control levels can be identified at which components are checked for potential damage and/or malfunction. Three levels of control are defined as follows:  Control level 0 (CL0) This level is triggered when the maximum acceleration recorded at the site a g,max is below the threshold value a g1 . The inspection must be carried out promptly and consists of a site survey focused on checking the following: control components electrical components The purpose of CL0 is to ensure the proper functioning of the devices essential for the immediate operation of the infrastructure. Control Level (CL1) Activated when the acceleration a g,max falls between the threshold values a g1 and a g2 . In addition to CL0, a rapid assessment of the main structures and reservoir banks near the hydraulic infrastructure must be performed with particular attention to: mechanical components In case of structural damage, a CL2 must be carried out immediately. Control Level 2 (CL2) This level is activated when the acceleration a g,max exceeds the threshold value a g2 . In addition to CL1, a thorough and immediate survey must be carried out, with a focus on: structural components 2.3. Detection of defects and malfunctions The main objective of the inspection form is to classify the most significant defects for each component and to assign a qualitative damage level to the infrastructure. In this study, damage is assessed through a qualitative approach based on the compilation of a specific form for each infrastructure component. Each form lists the potential defects or malfunctions along with their respective coefficients. For each defect, a Defect Severity (DS) is related to a value between 1 and 5, where DS = 1 indicates minor defects or malfunctions, DS = 5 indicates significant defects. Complementary to the DS value, the form permits the inclusion of significant risk situations. The inspector may indicate a risk to operational functionality by filling in the Functionality Compromised (FC) box for non-structural elements, if the defect is such as to compromise the operation of the infrastructure. In such cases, the DS value should also be calibrated based on the component ’s obsolescence and its seismic performance. For structural elements, when the defect may compromise the structural safety of the structure, the Structural Safety Compromised (SSC) box should be selected. In addition to the DS value, the coefficient K 1 representing the extension of the defect is introduced, with values between 0.2 and 1.0; the K 2 coefficient that represents the intensity of the defect also varies between 0.2 and 1.0. Coefficients K 1 and K 2 are attributed by the inspector via visual estimation. In the inspection form also include additional options for the defects: NA (Not Applicable), when the defect is not relevant for the component being assessed; NO (Not Observable) when the defect is not observable (for example, due to inaccessible area), and NP (Not Present) when the defect has been verified as absent. 2.4. Functionality checks In the proposed procedure, functionality tests have a significant role because they contribute to the definition of damage and help ensure compliance with minimum safety requirements. These tests support the inspector in identifying cases of Functionality Compromised (FC) and in determining the appropriate damage classification. During on-site inspections, functionality tests of non-structural elements must be performed, even in the absence of visible damage. For instance, in the case of electrical components, power must be restored following an outage to  