Technical survey stages
Preliminary investigation
The purpose and the main objective of the preliminary investigation stage is to provide initial information on the condition of the structure, the type and severity of the problems affecting it, the feasibility of performing the planned rehabilitation works and the determination of the need (or not) for a more detailed investigation.
The methodology to be followed for this control stage includes performing one or more of the following actions, depending on the size and complexity of the structure:
a) Review of construction drawings, specifications and records
b) Site observations of conditions (previous inspections)
c) Measurement of geometry, deflections, displacements, cracks, and other damage
d) Non-destructive testing
e) Exploratory removal
f) Sampling, testing, and analysis
Generally, only a limited amount of investigation is required at each step to determine
the feasibility – or necessity – of rehabilitation.
Detailed investigation
A detailed inspection of the structure should be conducted only after the preliminary investigation has been completed, the owner’s objectives are clear and feasible, and the detailed investigation objectives have been defined appropriately. Before starting the detailed investigation, the owner should have approved the budget and costs of such a detailed investigation.
The detailed investigation can be divided into five steps:
The results of the detailed investigation directly influence the conclusion of the assessment process, the choices of the various remediation methods to be considered, the estimated costs associated with each remediation alternative and ultimately the selection of the appropriate remediation method. As such, extreme care is required in the design and execution of the detailed investigation.
Further testing
The additional testing stage is divided into the following steps:
Additionally, during this stage of the investigation, an assessment of the structure or some of its components shall be carried out, based on the analysis of data and information gathered from archiving, inspections on-site, and testing of the materials to determine the adequacy of the structure.
