Perhaps not least as at the time of writing the Turkish government had arrested over 100 constructors for failing build according to the regulations, and more to come.

Before you read any further, relax. Construction standards are very high and highly regulated in Portugal. Earthquake-resistant structures are designed to protect buildings to some or greater extent from earthquakes. While no structure can be entirely impervious to earthquake damage, the goal of earthquake engineering is to erect structures that fare better during seismic activity than their conventional counterparts. According to building codes, earthquake-resistant structures are intended to withstand the largest earthquake of a certain probability that is likely to occur at their location. This means the loss of life should be minimized by preventing collapse of the buildings for rare earthquakes while the loss of the functionality should be limited for more frequent ones.

Interestingly following the devastating 1755 Lisbon earthquake the Gaiola pombalina (pombaline cage), an architectural, earthquake-resistant wooden structure was developed in Portugal in the 18th century for the reconstruction of Lisbon's downtown. It was made in wood to start with, but it has developed into the steel-reinforced structures we see everywhere as buildings are constructed.


Credits: PA; Author: PA;

Portugal - Earthquakes do not occur very frequently


In Portugal, there are rarely large earthquakes with strengths of more than 7.0, which cause damages within a radius of over 100 kilometres. Measured by the size of the country, earthquakes do not occur very frequently. 93 people died since 1950 by direct consequences of earthquakes. Compare that with amount of people who die in road accidents annually and you will realise that in 73 years that is a very low number. The strongest recent earthquake in Portugal happened on February 28th 1969 in the Rabat on the Canary Islands region with a magnitude of 7.8 on the Richter scale. The effects were felt in the Algarve but at a much-reduced level.

The Azores are a region that experiences a large number of light, two or more, on the Richter scale. These are very frequent but rarely felt even by residents of the Azores.


Highly regulated building standards


In Portugal, the structural engineers are highly regulated and highly specialised. The engineer who designs and subsequently approves the construction in an area that is considered to be at some risk of seismic activity (although low) is subject to a high level of responsibility for their work. Anyone who has constructed a villa or seen an apartment block being built will appreciate the quantity of steel that is built in to every pillar and roof. There are no shortcuts. Every pillar is interlocked with steel before concrete is poured.

Structural engineers design structures that must endure stresses and pressures inflicted through human use and environmental conditions. They configure structures, choose appropriate building material, inspect the construction work, and ensure the structural soundness of buildings and structures.

The Portuguese building regulation system has undergone significant changes in the last 20 years. Almost all building regulations currently in force are approved during that period. Some of these are resulted from the implementation of European Directives. Others are changed due to advances in scientific knowledge.


Who overseas quality control

Quality control during the construction works is assured by several parties: a private building inspector, selected by the developer, who guarantees compliance with the approved design; and a technical director, who is an employee of the contractor responsible for the construction works. The developer can appoint a design coordinator to give technical assistance in the contest to select the contractor during construction.

There must be a construction logbook at the building site. In this book, the technical director records relevant facts about the construction works, such as the beginning, suspension and conclusion of works, as well as modifications made to the approved design. The private building

inspector and the design coordinator also register their participation in the construction log book. The format of the logbook is established by law.

No records of any serious earthquake damage since 1722 & 1761

The very high standards of earthquake-protected buildings have resulted in impressive statistics. There are no available records of any serious damage caused by tremors for over 300 years.

Seismologists believe that the recurrence potential of an offshore earthquake similar to those in 1755 and 1761 is relatively low. And were a similar event to occur today, modern tsunami warning systems and disaster response practices, as well as superior building construction, would moderate the scale of damage and casualty.

Don’t compare Turkey with Portugal

Sadly, it’s becoming clear that some Turkish ministers had ‘turned a blind eye’ to sub standard construction methods by builders. Now many construction companies and their management are being arrested, no good closing the stable door now, the horse has already bolted.

This is not the case in Portugal. Building regulations are strictly observed and enforced when necessary. Add to that, the EU are constantly updating and revising building codes, especially regarding earthquake protection. As I have previously commentated, the EU don’t get everything wrong. Nor does Portugal.

Author

Resident in Portugal for 50 years, publishing and writing about Portugal since 1977. Privileged to have seen, firsthand, Portugal progress from a dictatorship (1974) into a stable democracy. 

Paul Luckman