The risk of sinkholes in Central Florida is clear, as stated by Tony Randazzo, UF professor emeritus now with Geohazards Inc. consultants in Gainesville, FL. “The I-4 corridor from Clearwater to Daytona, including St. Petersburg, Tampa, the Pasco-Hernando county areas …Marion and Sumter counties and the Tallahassee” are all prone to underground anomalies… There are sinkholes all over Central Florida; it’s really a matter of degrees” … That is Florida’s “Sinkhole Alley,” and Florida has the highest occurrences of sinkholes of any state.
This serious Florida issue attracted the attention of Correspondent Andy Fillmore for an extensive feature article in the April 21, 2013 edition of the Ocala Star Banner on Ocala.com. The article highlights Marion County homeowners whose recent sinkhole problems were successfully solved by the “Sinkhole Pros” at Foundation Services of Central Florida, Inc. in Ocala, the most experienced experts for sinkhole remediation in Ocala FL and the Central Florida region.
The majority of Florida’s sinkholes are within a 100 mile radius of Ocala, Foundation Services’ primary service area for FAST emergency response 24/7. The “Sinkhole Pros” at Foundation Services usually perform a pressure grouting technique known as deep compaction grouting for sinkhole repair, and complete 100 to 125 such jobs annually within a 100-mile radius of Ocala alone. They have successfully completed well over 2000 foundation and sinkhole repair projects to date…and climbing. That number will continue to climb as Florida experiences more extremes of excessive rains following drought conditions, in addition to the lowering of groundwater and reduction in underground hydraulic pressure from over-pumping.
As cited in the article, sinkhole remediation by Foundation Services involved compaction grouting. With skilled precision, monitored by the firm providing the engineering blueprint, injection pipes are inserted down to the depth of the eroded, fractured, collapsed bedrock. Then a low slump grout is injected to fill the voids and seal the limestone. The process is exacting. Throughout the pumping process, the foreman closely watches the jobsite gauges to monitor accumulated grout pressure. Simultaneously, he checks the surveyor-type precision equipment to detect any movement in the structure. This sensitive equipment can detect movement as slight as a 32nd of an inch.
The first sinkhole case study focused on 19-year residents of Southwest Marion County, Roy and Pat Meinson. They were shocked to discover that the cracks that kept appearing were caused by an actual sinkhole… and further to realize the extent. Their sinkhole remediation involved 15 truckloads of grout pumped through 29 injection points around their house. With the care taken by Foundation Services’ specially trained crews, the Meinsons were able to stay in their home during the three-week job.
In The Villages, Mary and Vic Ruzica had a sinkhole open around a pond about 50 feet behind their property “like an earthquake” on June 25, 2012. Their more extensive foundation stabilization required underpinning with 65 steel piers driven from the interior of the house down to the limestone “bedrock” at varying depths of 20 to 80 feet, and also the use of I-beams while they had to live elsewhere. Foundation Services then stabilized the soil with grouting through 36 exterior injection points specified by the geotechnical engineering consulting firm.
Foundation Services General Manager and Partner, Robert Stephenson, explained that “jobs may require grout or modified concrete fill for deeper remediation and chemical compounds for upper soils” … “We’ve done jobs like Booster Stadium that took 1,300 yards of concrete,” but most residential jobs fall short of catastrophic levels.
“We would gladly pass their names [Sinkhole Pros at Foundation Services] on to anyone struggling with foundation problems. In fact, our neighbor is using them now.”