Evaluation of the bearing capacity of existing buildings
Anti-seismic technology has progressed in recent years, thus ensuring the construction of new buildings with high resistance to natural phenomena and always with the protection of human life in mind. However, much of the existing construction has been implemented in times when knowledge about earthquake-resistant technology was limited. As a result, a large percentage of these constructions do not meet the criteria for anti-seismic behavior and are vulnerable with the main pathology being the low resistance to seismic actions, the reduced stiffness or plasticity and the presence of a soft floor – pilot mechanism.
The static adequacy study and the assessment of the bearing capacity of existing buildings in terms of resistance to external design actions, is a quantitative procedure to check the staticity of an existing body according to the applicable regulatory framework.
Therefore, with the static adequacy study, a conclusion is reached as to whether an existing building, with or without damage, will satisfy the required criteria set by the respective regulations.
The static test examines the behavior of the carrier in the required limit state of strength depending on its use, which corresponds to the combination of various critical external actions.
For the study of static adequacy of existing buildings and accordingly the construction material, the regulations of kan.epe & eurocode 8, par.3 are applied.
Specifically for buildings made of reinforced concrete, the dominant construction material in greece, the following procedure is followed:
The information for the static adequacy study data is mainly collected from the on-site measurements as described in the material quality control.
The data collected is also cross-referenced from different sources with the aim of minimizing uncertainties.
Design simulation is a process which results in the determination of the amount and arrangement of reinforcement, both longitudinal and transverse, and all elements involved in the vertical and lateral strength of the building. The design is carried out on the basis of the regulatory texts taking into account the usual practice at the time of construction.
According to eurocode 8, par. 3, the static adequacy study and the assessment of the load-bearing capacity of the building in question is aimed at the decision to intervene in the structure and the design of the structure’s static strengthening strategy.
According to the information collected, a simulation – model of the carrier is set up in the appropriate static software, in which the intensive sizes of all the structural elements are determined, resulting in the critical combination of seismic loading that results depending on the applied anti-seismic regulation and the corresponding assumptions.
For carriers made of different structural materials (structural steel, timber, load-bearing masonry), each case is examined separately and the corresponding regulatory provisions are followed to ensure an even and more accurate result.
The software used are the statics 2021 program of the MULTISOFT company and the RAF of the TOL company, among the most reliable in the greek market.
