Demolition Technique Nr. 101 Part 4- The Pie Face Slam

Source: Michael Kramer, CC BY-SA 3.0, via Wikimedia Commons

Part four in our bridge demolition series looks at the Pie Face Slam. When we think of the Pie Face Slam, we think of two different moves that exist in professional wrestling:

  1. The Physical Pie Face Slam- This move implies when the wrestler jumps from the top rope and lands on the opponent standing, with the hands in the face for submission. This usually knocks out the opponent, allowing the wrestler to pin him/her. This closing move is rarely used because of high risks of concussion and/or neck injury.
  2. The Real Pie Face Slam- This move, practiced in professional wrestling as side dish entertainment, implies that one wrestler throws a pie in the face of the other, shocking the victim and in most cases, brings the person down. The move provides humiliation yet it is considered harmless. An example of the second variant can be seen here:

Now implementing it in bridge demolition, the Pie Face Slam is the process of bringing down a slab structure or viaduct just by simply undermining the piers with explosives, and when the piers implode, the structure’s span is brought down to the ground, resembling the pie landing face first on the surface. While they both create a mess, in the case of the bridge version, it causes damage and destruction to vegetation and nearby places to a point that months are needed to rebuild the affected areas. In some cases, if houses and/or buildings are located under the bridge that is scheduled to be demolished, the inhabitants are forced to vacate and the places are razed prior to the Pie Face.

The Pie Face has become a very popular technique to use for demolition, especially for viaducts made of concrete that are at least 50 years old. Especially in Germany, during the age of reconstruction between 1945 and 1970, the motorway system (D: Autobahn) expanded as the population grew again thanks to a combination of immigration and the Baby Boom. The end result was urban sprawls that were laden with modernized motorways and their viaducts, stretching up to a kilometer long. This includes metropolises in North-Rhine Westphalia, Bavaria and Hesse, as well as cities like Hamburg and West Berlin. Sadly the viaducts are aging and are being replaced with newer ones built alongside the old ones. Once the new structure is open to traffic, the old one receives a much-needed farewell in the form of a Pie Face Slam, as you will see here in the film clip below:

We will be seeing more Pie Faces in the future as Germany, parts of Europe and the US face increasing problems with aging infrastructure and the need for bridges and viaducts to be demolished as one can see in this documentary (Click here). Already the Motorway 45 between Frankfurt and Cologne has become a “Dauerbaustelle”, meaning there is always construction on the motorway, namely the viaducts which need replacing. For the next 30 years, we will see more Pie Face Slams taking place along that route for dozens of viaducts have approached the end of their functional life and cannot take on increasing loads. When we do, future engineers will have a better idea how bridge construction, maintenance and deconstruction works, especially for tall viaducts, and will find better ways to take care of them in the future. There is no such thing as a 100-year old, zero maintenance bridge. Every bridge must be inspected and repaired to ensure they have a longer lasting life, no matter what bridge type is used today.