UTEP will study Asarco, City Hall demolitions

Monitoring the booms

By Cindy Ramirez \ El Paso Times

Juarez residents came out early Saturday morning before the Asarco demolition. (Jesus Alcazar / El Paso Times)

When the Asarco smokestacks and the City Hall building tumble down this weekend, a group of UTEP researchers will be looking beyond the wow of the demolitions.

“It’s definitely an opportunity for us to collect data we wouldn’t normally have access to,” said seismologist Hector Gonzalez-Huizar, an assistant research professor at the University of Texas at El Paso.

Gonzalez-Huizar, along with professors and earthquake experts Diane Doser and Aaron A. Velasco, will work with a number of graduate and undergraduate students to collect data on the seismic waves the demolitions will produce.

They will deploy 40 temporary seismic recording stations between Asarco and City Hall to record the impact of the explosions. The Asarco smokestacks are expected to go down around 6:45 a.m. Saturday, and City Hall is scheduled for demolition around 9 a.m. Sunday.

“We’ll cover the area between the two sites across Downtown and, of course, UTEP,” Gonzalez-Huizar said.

The objective is to learn how El Paso’s Downtown would respond to an earthquake, but the data will also help the researchers determine whether the east Franklin Mountain fault ends or continues under Downtown El Paso and into Juárez. The U.S. Geological Survey says it goes through to Juárez,

Gonzalez-Huizar said, and added that the Universidad Autonoma de Ciudad Juárez may also set up seismometers on that side of the border.

The data may also identify other geological structures that have not been identified in the past.

Juarez residents came out early Saturday morning before the Asarco demolition. (Jesus Alcazar / El Paso Times)

Last fall the city hired AMEC Environment and Infrastructure Inc. to conduct a geotechnical/pre-demolition feasibility study that looked primarily at the impact the implosion of City Hall might have on the nearby Union Pacific Railroad tracks and its 20-foot-tall retaining wall. The AMEC study showed there was no evidence of shallow bedrock or cemented soils that would amplify ground vibrations –which means there’s low potential for damage to the wall. It also said the ground vibrations had a low potential for amplification and would travel only short distances.

The city-commissioned study didn’t look at the Asarco impact, as that is under the jurisdiction of a bankruptcy court trustee and is not owned by the city.

But the seismic recording stations between the Asarco stacks and City Hall will provide actual data comparing underground activity before, during and after they’re torn down — and the difference between the two types of demolitions.

Explosives will take down Asarco’s 825-foot and 612-foot stacks, which are expected to basically tip over onto their sides. Explosives will also be used to implode the 288-foot-tall City Hall, but the building will fall mostly inward and onto its own footprint.

The University of Texas at El Paso researchers will put out the seismic stations on several sites today and measure the ground vibrations through the end of Sunday. The university’s John W. Kidd Memorial Seismological Observatory on campus will also be used to measure waves during the demolitions.

“We’re excited about the opportunity to do this research in our backyard,” Gonzalez-Huizar said.

Cindy Ramirez may be reached at cramirez@elpasotimes.com; 546-6151.

Source: http://www.elpasotimes.com/ci_23008549/utep-will-study-demolitions