Resistant walls

Piura is actually a seismic zone – we just must make safe buildings.

 

SULLANA, Peru – The land shook on Monday, April 2^nd, 2012. The first record of Peru’s Geophysical Institute (IGP, as its initials in Spanish) marked 6.2 magnitude in Richter Scale and VI intensity in Mercalli Scale. Later, it was modified to 5.0 magnitude in Richter’s and III intensity in Mercalli’s, taking Piura City as a reference.

 

The epicenter, that originally was located 25 miles to the west of Sullana City, ended to correct to 12 miles to the southeast of that spot, 57 miles depth. At least, the department’s coast felt it strong causing the people to overreact – the most were resting at home. It was eigt past ten at night, local time (0308 GMT, April 3^rd, 2012).

 

The mechanism of quakes in Piura is not different from the western coast of South America. The phenomenon is caused by the subduction of Nazca Plate against the South American Plate. Said simple, the subduction is the embedding process  of a huge mass of land beneath another else. The pressure produces such as energy, that it releases little by little, or shocking, through seisms (quakes).

 

The Nazca Plate is a big surface which eastern side extends from Panama, at the north, to the Chilean southern edge in the opposite side. The South American Plate shocks, or it rather rises above, starting in the Peruvian Pit that runs from La Libertad Shores to Chilean Northern. The quakes, as well as the volcanic eruptions, break out at this side of the world begin right there, and it explains the seismicity in Peruvian Central and Southern, reported in the last 500 years when written records began to be.

 

Telluric Northern
Although it also trembles, and basing upon these records, the Peruvian Northern hasn’t been too prolific in those events. However, in the last 100 years, it has been reported three major quakes including material damages and casualties.

 

In 1912, a strong move shook Piura Department, from Paita to Huancabamba. The intensity has not been registered. On December 12^th, 1953, it was produced a VIII intensity quake (Mercalli Scale). Some years later, February 7th, 1959, the coast between Tumbés and Lambayequé, Piura in the middle, trembled again.

 

Since 2000, when FACTORTIERRA has been in service, there is an average of four to five quakes per year with magnitudes over 4.0 in Richter Scale that put the Piura people on alert.

 

Urban silence
Local specialists coincide that the seismic activity has not increased but it has better reports now and the people seems to be more alert. However, the preventive exercises are not assumed by the most of population. The evacuation drils accomplish, noteever wwell, in some public entities and schools. The rest of people is only there to watch the re-eenactment.

 

In the other hand, a good part of the key urban structure  is characterized to have narrow streets and buildings that have gone deteriorating by other very Piura phenomenon – rains. Eguiguren House in Piura Downtown has gone bringing down little by little until destroying completely. It was useless that Peru’s National Institute of Culture declared it as interesting.

 

Between 1999 and 2000, Piura National University’s School of Architecture did a student’s assignment, and as the former students commented us, it was found until 30 types of soil completely different in a very reduced space.

 

In Sojo, Miguel Checa District, the old Checa Family’s estate house deteriorates day by day because of the inaction of its supposed executor who prefers to see how the history falls down in pieces instead of avoiding an ashaming show that denotes lack of culture.

 

Also, the disordered growth of the cities in high-risk zones, because of land traffickers, is another ticking bomb, plus the precariety of many buildings. A quake would be the cherry on the cake.

 

Legal buildings
Whether a vanguard design or something simpler, all the buildings that are made must be based upon the National Building Code (RNE, as its initials in Spanish) subscribed by Peru’s housing Ministry. This entity launched in 2012 the E.100 Rule that innovates the building by incorporating an old buddy of Piura people – bamboo or Guayaquil cane. Among some of its recommendations, it establisheds that over the cement base, it can be erected bamboo partitioning and messanines. Speaking theoretically, this combination makes the building to be quake-proof.

 

But not all buildings admit bamboo as an input that absorbes the shock waves. The RNE establishes the safety margins that can be defined as the additional percentages of material to improve the resistance of a building before a phenomenon in particular. It’s also named material overmeasuring, that is determined by the geologic background of the zone where it’s built, and that for the RNE are already properly identified along Peru.

 

The specialists we asked for say that the RNE is something like the Peruvian Bible of Architecture and engineering. Nobody can design or make by unfollowing its guidelines.

 

        
Safe Reading

An example of how to build something attractive but attached to the RNE is the Chulucanas Library, a building where not only it’s going to read but many educational and even political activities have been performed as the campaign of the march for water.

 

The structure is made of cement and there are 9.8-inch wals with double net in its basement. The challenge was to make it steady and resistant to almost everything, being aware that the terrain was a material dump and it’s amid the course of many creeks coming down Ñañañiqué Hill during the rainy seasons.

 

The building is fit to the so-called structure geometry, which the beams design responds to the shape design, what means absorbing the energy of a quake. Only in 2010, it was felt four with magnitudes over 4.0, almost all with epicenters located in Buenos Aires District, about 22 miles to the northeast of Chulucanas City. The library was finished in May 2011.

 

As the Nazca Plate’s subduction process continues, the happening of a quake can break anytime, not respecting day, neither hour (the quakes are unpredictable). Peru is part of the Pacific Fire Ring, the area of the Earth where the seismicity and the vulcanism are more active.

 

We the people only have to be prepared but also conveniently informed, and demanding all the factors we have known here to be respected. That is the fine difference between appreciating the Nature and being under its threat.

 

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