–Photo by Roy Rose
Two small excavators are working in the actual shaft, and between them is the manhole that is being removed as the digging progresses toward the damaged interceptor, still approximately another 30 feet below their current depth of about 30 feet. Two sets of “wales” (horizontal bracing) are in place in this photo, and a third set is also being constructed at this time.
–Photo by Roy Rose
Above ground, work also continues with the large excavator shown here removing a section of the manhole that is located in the excavation site, literally “Ground Zero” for the collapsed 11-foot interceptor 60 feet underground.
Work continues at the site of the 15 Mile sewer collapse and sinkhole repair and restoration. With bulkheads (dams/gates) installed, cleaning of the pipeline is underway, and this will enable further, more thorough inspection. This is followed by “chemical grouting” which serves to repair damaged areas in the drain walls, and additional grouting with a mortar-like material that will seal cracks and joints and fill voids outside the existing pipe is also being performed as needed.
Engineers are hard at work to help keep the project moving forward while at the same time working through delays that weren’t known at the onset of the recovery efforts. The recovery shaft has been extended an additional 20 feet from first estimates, adding to the time and work required, and they’re now working with the current contractor along with a second one who will be installing the 9.2 foot diameter Hobas pipe inside the 11 foot interceptor.
The recovery shaft, approximately 300 feet long and 28 feet wide, is bordered 260 piers that help to form the protective barrier for the site. Each pier has approximately 24 cubic yards of concrete, 6,400 yards overall, and more than half of them also have a 70 foot long steel I-beam installed inside.
Macomb County Public Works Commissioner Candice Miller and AEW Project Manager Louis Urban discussing progress at the damaged interceptor site.
Hobas is a polymer-enhanced pipe that will provide a strong and secure lining for the 300 foot excavated area, as well as 3,700 feet of the pipeline between Control Structure #3 (CS3), located on the south side of 15 Mile, approximately one-quarter mile west of Garfield, and the damaged section where the sinkhole first appeared.
Plans are being made and work progressing on demobilizing smaller diameter bypass piping and equipment that is no longer needed, to help facilitate the final remediation for the entire work area. Everyone associated with the recovery project wants to help residents, businesses and motorists return to their normal routines and lifestyles while at the same time working to provide complete and effective repairs of this very important interceptor.