Virtual Earthquake Reconnaissance Team (VERT) Summary by Juan Obando [1], David Ugalde [1], Diego López-García [2],[3]
2015. Pontificia Universidad Catolica de Chile.
In the area affected by the earthquake, which includes the cities of Illapel (30,000 inhabitants), Coquimbo (200,000 inhabitants), and La Serena (198,000 inhabitants), the percentage of housing units with damage exclusively caused by strong ground motion was low. However, greater damage was produced in dwellings as a consequence of the tsunami generated by the earthquake.
Figure 1. Reinforced concrete building structures presenting substantial damage in the nonstructural components of the first and second floors owing to the tsunami. Coquimbo.
The dwellings in the affected area are mainly masonry structures (of one or two storeys), and the remaining dwellings are reinforced concrete structures, adobe structures and wood structures.
Masonry structures of one or two storeys
The dwellings in the area affected by the earthquake were mainly masonry structures of one or two storeys, only a small percentage of which were damaged exclusively by the strong ground motion. More significant damage was caused by the tsunami. In some cases complete structures were ruined.
Reinforced concrete structures
Only one case of considerable damage (the Puerto Bahia condominium, Coquimbo), as far as the authors are aware of, was caused in reinforced concrete building structures as a result of strong ground motion. Overall, this type of structures stood up well to the earthquake. However, some reinforced concrete building structures presented damage in non-structural components at the first and second floors due to the tsunami.
The Puerto Bahía Condominium, Coquimbo
The damage in the Puerto Bahía condominium was the most interesting structural damage observed as a result of strong ground motion because of the particular kind of failure that only occurred in this building. The damage was concentrated in specific areas of the slabs and occurred at the same location of the slabs in almost all the floors of the building. This building has an irregular C-shape plan, and torsion could have imposed non expected stresses on the slabs, which might have not acted as rigid diaphragms. Besides, the wall located next to the failed slabs is discontinuous on the first two stories, creating a vertical irregularity. Apparently, the slabs did not have sufficient capacity to transfer horizontal loads effectively. However, other main structural elements such as beams and walls were not significantly affected by the earthquake, hence the building is repairable although it may be exposed to the same type of damage in a future earthquake.
Adobe structures
Adobe structures are old traditional buildings. The greatest damage due to strong ground motion was observed in this type of structures, some of which had or will have to be demolished.
Wooden structures
Wooden structures are typically found in rural areas and they performed well in the earthquake; there was no perceptible damage observed in these structures. However, in some wooden structures damage due to rockslides and/or the tsunami was evident. Contrary to reinforced concrete or masonry structures, many of the wooden structures impacted by the tsunami had severe structural damage or were completely displaced.
Read the detailed report: Housing – Illapel Earthquake (3.2 MB PDF)
Juan Carlos Obando Fuertes, Pontificia Universidad Católica de Chile.
[1] PhD Candidate. Department of Structural & Geotechnical Engineering, Pontificia Universidad Catolica de Chile. Av. Vicuna Mackenna 4860 Macul, Santiago RM 782-0436, CHILE
[2] Associate Professor. Department of Structural & Geotechnical Engineering, Pontificia Universidad Catolica de Chile. Av. Vicuna Mackenna 4860 Macul, Santiago RM 782-0436, CHILE
[3] Researcher, National Research Center for Integrated Natural Disaster Management CONICYT FONDAP 15110017. Av. Vicuna Mackenna 4860 Macul, Santiago RM 782-0436, CHILE
