Sinkhole & Geotechnical Investigations
CES conducts geotechnical investigations to determine the cause of soil instability and failure, which is often associated with damage to homes, buildings, and structures. Soil instability can be the result of shallow and/or deep-seated sinkhole activity, wetting and trying of swelling clays, deterioration of buried organic debris such as tree stumps, and trunks, collapse of buried structures such as long-forgotten septic tanks and culverts, and improper compaction of soil prior to construction. Investigations typically begin with geophysical surveys such as ground penetration radar (GPR) and electrical resistivity (ER), followed by foundations inspections, test drilling, and laboratory analysis of
soil samples. The following are examples of investigations we have conducted.
Failed Limestone Mine Settling Pond Sinkhole Study
Investigate the sudden loss of several million gallons of limestone sludge from an unlined settling pond in the bottom of former limestone quarry. Discharge posed risk to the underlying Floridian aquifer. Conducted Ground Penetration Radar (GPR) and Electrical Resistivity (ER) surveys to map subsurface voids and conducts and drilled suspect areas. Supervised the excavation of remaining sludge and sealing of voids, and conduits using Portland cement grout. Tested the seal of the pond bottom before putting pond back into service.
Ready Mix Plant Collapse
Pasco County, Florida
Investigated the large-scale collapse of concrete pavement and a wastewater treatment pond at and active concrete ready-mix plant, Ground Penetration Radar (GPR) surveys were conducted and test borings were advanced to determine if the collapse was due to sinkhole development or from complications related to the recent subsurface installation of a large diameter natural gas transmission line 60 feet below the facility. Investigation conducted the damage was caused by a pipeline construction as sand washed into a large void crated around the lateral borehole. Designed a remediation plan that included temporary relocation of equipment and structures, removal or concrete debris, dewatering, excavation of loose sand 30 feet deep, backfilling and compacting in lifts with clayey soil, and returning the site to usable condition. Provided remediation construction oversight.
Proposed Hospital Construction Side GPR Reconnaissance
Levy County, Florida
Conducted reconnaissance Ground Penetrating Radar (GPR) survey of 20 acre parcel being considered for construction of new hospital. Survey identified numerous and variable abnormalities, including opposite down warping of continuous near-surface reflection with embedded multiple high-intensity parabolic reflections with an overall V-shape, sharply opposite down warping of near surface reflection with high intensity parabolic reflectors directly below the apex of the down warping, a series of parabolic reflectors that extend below discontinuous area of the near continuous surface reflection, vertical parabolic reflectors that extend below down warping of the near continuous surface reflection, and increase in vertical signal penetration of selected parts of the GPR profile. Conditions suggested sinkhole activity so extreme that the site was abandoned without confirmatory drilling.