‘Damage’ Tag

Sinkhole from Sewer Failure

Photo Credit: Karl Jansen

This is a special kind of sinkhole probably caused by the failure of a storm sewer system connection. Sinkholes like this one form when and where a sewer pipe fails, allowing rainwater to wash earth material into the pipe and down the system. When the earth is washed away, the above material collapses down causing a hole to form. Due to the close proximity of this sinkhole to a catch basin, this sink hole was probably caused by a failure of the connection of the sewer pipe to the structure.

Failing Infrastructure

Photo Credit: Karl Jansen

This is the infamous Stadium Blvd Bridge in Ann Arbor, MI. For the past several years, this bridge has literally been falling down, waiting on funds for a rehabilitation project. What you see on the near side of the bridge is an exposed beam, which used to be the south side of the bridge. Last year, the south half of the bridge was removed for public safety reason, because officials were worried “football size” chunks of concrete would fall on a car or pedestrian. This fall, the City of Ann Arbor with its secured funding will finally undertake this long overdue project.

Exposed Rebar on Bridge

Photo Credit: Alex Mead

Seen here is an example of the crumbling infrastructure often reported by the media. As can be seen in this photograph of the top side of a bridge, all the rebar of the side barrier is exposed along the roadway. This is especially bad because when salt is applied during the winter to prevent ice buildup on the roadway, the rebar is eroded even faster than it would be if it were only exposed to air and water. This is due to the chlorides in the salt that become active when dissociated in water.

Wall Crack

Photo Credit: Nathan Shoemaker

Pictured above is a floor to ceiling crack in a masonry wall. Cracks like this can be seen in many buildings where differential settlement is occurring. Differential settlement is caused by a combination of weak or erodible soil, poor foundation design, and sometimes seismic loading of the sub-grade of the building.

Crumbling Infrastructure

Photo Credit: Alex Mead

A perfect example of the crumbling infrastructure we all hear about in the media. The problem with this bridge pier is obvious to any civil engineer, but may be not understood from a simple look. The problem is the fact that the reinforcing steel (rebar) is exposed to the elements and is rusting. The rebar takes all tension loads, prevents shrinkage of the concrete, and provides shear resistance. When the rebar rusts strength is lost and the ability of the bridge pier to perform its job in supporting to above roadway is compromised.