The NSR-10 assigns each departmental capital an acceleration coefficient (Aa) and a velocity coefficient (Av), and with them a seismic hazard zone (table A.2.3-2). On the Caribbean coast, Barranquilla, Cartagena and Valledupar are in the low hazard zone; Santa Marta, Montería, Sincelejo and Riohacha, in the intermediate zone. The difference changes the detailing the design requires.
The values
Barranquilla: Aa 0.10 · Av 0.10 · low. Cartagena: 0.10 · 0.10 · low. Valledupar: 0.10 · 0.10 · low. Santa Marta: 0.15 · 0.10 · intermediate. Montería: 0.10 · 0.15 · intermediate. Sincelejo: 0.10 · 0.15 · intermediate. Riohacha: 0.10 · 0.15 · intermediate. For reference, Yopal, in Casanare, is in the high hazard zone: 0.30 · 0.20.
What changes from one zone to another
In the low hazard zone, the code allows structures with a lower energy dissipation capacity and simplifies the irregularity checks for occupancy groups I and II (A.3.3.6). In the intermediate zone, systems with moderate energy dissipation capacity are required, with more reinforcement detailing requirements. That is why the same building is not designed the same way in Barranquilla as in Santa Marta.
The map is not everything
The forces also depend on the soil type and the building's use: a soft soil amplifies the shaking, and a school or a clinic is designed for larger forces. We explain it in occupancy groups and in are there earthquakes in Barranquilla?.
Source: NSR-10, Title A, table A.2.3-2 and section A.3.3.
Frequently asked questions
What is Barranquilla's seismic hazard?
Low, with Aa = 0.10 and Av = 0.10, the same as Cartagena and Valledupar (table A.2.3-2 of the NSR-10).
And Santa Marta?
Intermediate, with Aa = 0.15 and Av = 0.10. Montería, Sincelejo and Riohacha are also in the intermediate hazard zone.
