No Mr. Steiner, it was not a “Miracle”

If it were, then we can produce more miracles like this

Jose F. Gomez, President of Crete & Forms

First and foremost, my prayers are with all the victims and families affected by the fires in the Los Angeles area. It is never good to write immediately after a tragedy, unless it is with the purpose of preventing future events like this.

We have all seen the image of this house standing, almost unscathed, while the neighboring structures burned down. The owner, Mr. Steiner, said it was a “miracle”, but he prepared this property for the miracle to happen; as he also said in the NY Post interview, it was built to withstand common earthquakes in the California area. The house, according to him, was built using stucco and stone, materials that are noncombustible, therefore the house was also prepared to resist the fire. The owner, the architect, and the contractor prepared the miracle, and, in addition to the Steiner family, the insurance company is also very happy.

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Similarly to the aforementioned natural disasters, wildfires and earthquakes, we also face hurricanes and tornados. These events can produce wind speeds of over 200 mph which exert immense force on the structures and carry debris that act as projectiles. Analyzing maps of the occurrence of events, we have highly active seismic areas in the Pacific Coast, tornados not only in the “alley” but last year we witnessed many in Florida and other states, hurricanes almost every single year affecting the Atlantic Coast, from Texas in the Gulf of Mexico to Cape Cod in Massachusetts, and wildfires mainly in California, but other cases, including Hawaii.

The questions are then, can we construct buildings that can resist the natural events? If the answer is yes, what is the reason we don’t do it now? What needs to happen in order to make it possible?

To see how we can produce more miracles, let’s review individual cases and structures that survived. Starting with hurricanes and finishing with earthquakes.

In the last two hurricane seasons we had Idalia, Helene, and Milton, highly destructive events, with both, winds and storm surges. But there is one impressive image that caught our attention. It was structure in Mexico Beach, Florida, after Hurricane Michael in 2018. The house stands on concrete piles and its walls are cast in concrete. They are easy to build, with materials that are readily available and can be pre-cast or cast-in-place.?

Regarding tornados, again, using images of structures that withstood the event, this is from Builder magazine in 2022, taken in La Plata, MD. We see buildings, mostly brick and mortar and concrete structures, standing while all the surroundings are flattened. In the note, Laura Spicer writes “Structural experts are quick to point out that almost no home is designed to withstand the force of a super tornado (with the possible exception of some concrete monolithic domes).”? We already have many examples of monolithic concrete buildings, not exactly domes, but their walls and slabs are poured in the same event, they will withstand better than stick structures.

We all saw the surreal image of a house in Lahaina, HI, after the wildfire in 2023, whose owners also referred to it as a miracle. But again, the Millikin family remodeled the house a few years back and prepared the house to prevent it from catching fire, even though it is built with a wood frame. The key in this case is that neither the material at the base of the fa?ade, nor the immediate perimeter of the house were combustible. With this basic “trick”, the embers that are going to hit the walls and land at that junction, the wall and the ground, will die before the structure catches fire.

So, as we mentioned, Mr. Steiner is confident their house is well prepared to withstand some earthquakes, based on the quality of the foundations and the structure itself. We can also see other examples of structures that have already survived magnitude 7, and above, seismic events. As we all know, both sides of the Pacific Ocean, in Asia and the Americas, from Chile to the United States, have the subduction of tectonic plates and suffer many seismic events. Similarly, the Mediterranean has activity and one of the most recent and devastating events occurred in Turkey in 2023, exactly 2 years ago. Turkey is a large cement producer, and most structures are built using reinforced concrete, the Tunnel form construction method is very common, even to cast mid-rise and high-rise buildings. Last year, during the WCEE in Milan, Italy, a paper was presented analyzing Tunnel-Form Buildings damages after the earthquakes. It is also important to state that a new building code in Turkey was implemented after another earthquake in 1999, with two revisions in 2007 and 2018. This study focuses on two new buildings, constructed under the newest codes, and concludes that one presented minimal cosmetic damages, nothing structural, and the other sustained some structural cracks; neither one collapsed and there were no victims.

We should get together with the State, County and City Building departments, the insurance companies, Universities and institutions like ACI, to update the codes and train inspectors to build residential units that allow more of these “miracles” to happen. The events are going to occur, sooner or later, and the only thing we can control is how well prepared we are.

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