Problem:
A homeowner from the City of Green Bay, Wisconsin was cleaning up his yard in late November of 2019 when the back tire of his lawn tractor got stuck. Puzzled, the homeowner freed his lawn tractor and discovered that he had a large sinkhole in his yard. The hole had an opening that was roughly three feet in diameter and expanded to about a six foot diameter at the bottom of the hole and was about five feet deep. The homeowner was confused as to how a sinkhole would have developed in his yard since he lived right in the city, only a few blocks from Lambeau Field. He contacted the city’s public works department who came out to his house and determined that the hole was not caused by ruptured water lines which could have caused washout or by an abandoned culvert.
Summary:
Unsure of what do with the hole and concerned about its potential impact on his home’s foundation the customer contacted RaiseRite on a Friday afternoon. A representative from RaiseRite was at his home the very next Monday to inspect the area to see if the sinkhole could be addressed. Wisconsin sinkholes are relatively small with larger ones not developing more than ten feet across. Sinkholes in Wisconsin are often caused by limestone or dolomite in the ground. Limestone and dolomite is rock that is easily fractured and can dissolve by water. Water seeping down beneath the soil can cause erosion in the limestone or dolomite which can lead to underground cavities developing. Water will flow into these underground cavities taking the surface soil with it which in turn will cause a sinkhole. The summer and fall of 2019 had a large amount of rain in Wisconsin which is believed to have aided in the development of this particular sinkhole.
Solution:
After observing the sinkhole and researching sinkholes in Wisconsin the customer was contacted and a plan to address the sinkhole was proposed to the customer on Tuesday, the very next day. Because the sinkhole was smaller and far enough away from the customer’s home, the plan was to fill the sinkhole with FillRite Technologies FillFoam and monitor the area. FillRite Technologies FillFoam is a flowable fill foam engineered for large cavity and void filling. After the hole is filled the area will be observed over the upcoming winter and following spring to see if further action would be needed. At that point if continued settling of the area occurs, HMI’s Deep Foamjection™ process may be required to stabilize the soil. Deep Foamjection™ is the process of injecting high density foam deep into soils to bind the soil and give soft soils stability.
The low-cost of FillFoam option made it an easy choice for the customer and RaiseRite was on-site that Wednesday and the sinkhole was filled by pumping 278 pounds of FillFoam into. Once the hole was filled topsoil was placed over the top of the FillFoam. Total time of project from arrival to clean-up was one hour.