Featured Projects
FPL St. Lucie Nuclear Power Plant, Cooling Water Discharge Pipe Replacement
St. Lucie County, FL
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At FPL’s St. Lucie Nuclear Power Plant in the late stages of an outage for one of the nuclear power generating units it was discovered that existing carbon steel pipes for the cooling water discharges had become corroded and required replacement via an “emergency response” mode. Dunkelberger was retained by UESI as a member of the design-build team to provide geotechnical services involving exploratory work (subsurface investigation) and construction support (monitoring and testing). As part of the pre-construction services, Dunkelberger used the gathered subsurface data to formulate geotechnical criteria for support (bedding) of the new piping and also for stability of temporary sheetpile walls. During construction, Dunkelberger provided round-the-clock (24/7) geophysical (ground vibration) monitoring of sheetpile driving and soil compaction activities. Since regulatory restrictions prevented soil samples leaving the Plant, Dunkelberger established an on-site laboratory for soil gradation and Proctor tests. Dunkelberger’s quality control testing covered pipe backfill placement and structural concrete for the headwall. The project was completed in 60 days. |
Honore Boulevard Improvements, Phase 2
Sarasota County, FL
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During utility installation work, the contractor discovered a large, buried (latent) deposit of trash-like debris within the roadway right-of-way. Sarasota County engaged Dunkelberger, under its continuing services contract, for fast-track exploratory work and geotechnical engineering evaluation of options for removal and disposal of the debris. Dunkelberger recommended a partial removal option, coupled with geosynthetic reinforcement of the pavement section, that saved the County $200,000 in debris disposal costs. Dunkelberger’s quick response, and practical engineering recommendations, minimized construction delays. As part of the engineering evaluation, Dunkelberger completed an environmental assessment of potential contaminants in both soil and groundwater in the area of the debris deposit. The Florida Department of Environmental Protection (FDEP) approved Dunkelberger’s assessment allowing the partial removal option to be implemented and without delay. Construction of the alternate pavement section, with geosynthetic installation, was field inspected and tested by certified (CTQP) engineering technicians from Dunkelberger. |
Palm Beach Renewable Energy Facility No. 2
Palm Beach County, FL
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Dunkelberger was retained as a geotechnical sub-consultant as part of the design effort to prepare preliminary plans and specifications for bidding by design-build vendors. ` Subsurface data in the planned facility area was collected on a fast-track basis using multiple drilling crews from Dunkelberger to complete deep test borings. The data was incorporated into a Baseline Geotechnical Report that included preliminary design criteria for structure foundations, both shallow and deep alternatives, slabs, retaining walls, and pavements. Under a separate services authorization, Dunkelberger prepared earthwork specifications for backfilling of a large, existing lake within part of the planned facility area. Subsequently, Dunkelberger carried out a quality control (QC) program involving field oversight and testing, including the monitoring of piezometer and settlement plate installations, during the lake backfilling and surcharging. |
Keys Gate Charter High School
Homestead (Miami-Dade County), FL
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The project site lies in south Miami-Dade County with a characteristic marl (calcareous silt) overburden soil atop limestone bedrock. The initial geotechnical recommendations called for wholesale removal of the silt layer from within the planned building (structure) area. Subsequently, Dunkelberger was retained in a Value Engineering (V.E.) role to evaluate the initial recommendations and present, if appropriate, less expensive options for foundation support of the structures. Dunkelberger completed field exploratory work to verify the depth, thickness, and consistency of the silt layer as well as to obtain an undisturbed tube sample for laboratory consolidation (compression) testing. The field and laboratory data indicated that the silt was stiff (highly over-consolidated) due to desiccation and therefore only nominally compressible within the projected range of foundation (spread footing) and floor slab loads. Dunkelberger concluded that removal of the silt layer was not necessary and that the building area could be adequately prepared using standard construction measures (stripping, proof-rolling and placing of well-compacted, granular pad fill). The V.E. results saved approximately $100,000 in earthwork costs and also accelerated the construction schedule. Supplemental services by Dunkelberger, carried out by certified engineering technicians, included field observation and testing of earthwork, sampling and strength testing of structural concrete, and inspection of post-tensioning of the elevated floor and roof slabs. |

