On Friday, the members of the ATC reconnaissance team reviewed their individual observations. Specific buildings were also identified for ongoing monitoring.<!–more–>

Having reached out to local engineers, building owners and residents, the team received helpful information about the earthquake itself, as well as the consequent building performance. Some residents invited our team members into their apartments to see the damage in person. The 9/19/17 earthquake caused structural damage — damage to buildings — precipitating 44 collapses. Many buildings also experienced non-structural structural damage (i.e. the shaking of contents within the buildings), or damage caused by geotechnical failure.

On this day, Laura Hernandez also assisted University at Buffalo Professor, Andreas Stavridis, with the instrumented inspection and measurement of a damaged building. Prof. Stavridis, member of the ATC team, conducted instrumented investigations of one building each day throughout this reconnaissance trip.

On Thursday Laura’s team continued its route around the southern neighborhoods. They continuously saw buildings with nonstructural masonry infill walls that seemed to have acted as lateral resisting elements, evident by the in-plane damage.

On Wednesday, the ATC reconnaissance team sub-groups were rearranged. Ramon and Jennifer’s group visited the Condesa neighborhood in the northern part of the city. Here the team assessed two buildings, one of which suffered some damage, and the other nearly none. Another group, including Laura Hernandez, focused on the southern area of Mexico City where they saw several structures with distinct damage

GMS engineers and the other members of the Applied Technology Council (ATC) reconnaissance team arrived in Mexico City and coordinated their plan of action to study the effects of the 9/19/2017 earthquake on building structures. The first morning, they met at the WSP office to organize the reconnaissance for that day. In order to maximize the use of the researchers’ time, the team was divided into three smaller groups. Each went to a different section in the city to evaluate damage.

GMS engineers departed for Mexico City on Monday to be joined by remaining members of the Applied Technology Council (ATC) reconnaissance team reviewing the aftermath of the 9/19/2017 earthquake. The goal of this reconnaissance mission is to perform detailed assessments of reinforced concrete structures with all levels of damage. The reconnaissance will focus on identifying the likely cause of collapse in concrete buildings that performed poorly, and the likely cause of good performance in non-collapsed buildings in the immediate vicinity.

Mexico is one of the world’s most seismically active regions, sitting atop several intersecting tectonic plates. On September 19, 2017, a magnitude 7.1 earthquake hit the Greater Mexico City area killing 370 people and collapsing 40 buildings. The quake occurred on the 32nd anniversary of the 1985 Mexico City earthquake, which killed around 10,000 people. The 1985 quake was commemorated, and a national earthquake drill was held, at 11 a.m. local time, just two hours before the 2017 earthquake. Twelve days earlier, the even larger 2017 Chiapas earthquake struck 400 miles away, off the coast of the state of Chiapas.

In support of ongoing U.S. Government-funded research and development projects in earthquake engineering, the Applied Technology Council (ATC) Endowment Fund is sponsoring a team of experts to investigate the performance of buildings in Mexico City following the event.