Case Histories in Unsuccessful Pressure Grouting to Remediate Sinkhole Related Subsurface Conditions for Residential Structures in Florida

Pressure grouting is among the ground improvement methods, which is used to remediate the problematic subsurface geological conditions associated with karst environment and sinkhole activities in Florida. A typical subsurface remediation program may include some combination of shallow chemical grouting, deep pressure grouting, or application of deep foundation (minipiles, micropiles, or full size piles). There are professionals who believe no matter how severe the condition, deep pressure grouting is capable of remediating the problematic subsurface geological conditions associated with karst environment/sinkhole activities and provides reliable and dependable effective compaction of the subsurface soils. Deep pressure grouting on its own may not be the most effective, reliable, and dependable remedial measure for all scenarios. Case histories of unsuccessful remediation of sinkhole related subsurface conditions using deep pressure grouting for residential structures are presented. Failures will be discussed using in situ test data related to subsurface conditions before and after implementation of the remediation program. There are scenarios in which application of some form of deep foundation is required, whether due to severity of sinkhole activity (i.e., securing the structure) or due to value engineering (i.e., optimum engineering and construction effectiveness). An introduction about sinkhole activity in Florida’s geological strata and sinkhole investigation for residential properties in Florida are also presented.