Scope and field context
Project scope and field context
Tyndall Air Force Base is going through the process of rebuilding the entire AFB. The purpose of the Geotechnical Investigation by ATI Geologica is infrastructure updates for Tyndall AFB. ATI Geologica completed twenty-five (25) Cone Penetration Tests to depths ranging from 15 to 60 feet (ft) in December 2022. The tests were performed using a track-mounted Geoprobe 7730DT which was anchored when on bare ground using two helical anchors and when on concrete and asphalt using drop-in anchors and bolts. The Vertek instrumentation was advanced at a rate of approximately 2 cm/s (0.8 in/s). The data was recorded using the Vertek DataPack and their proprietary software, CPTSND. The data was then processed using Vertek’s Coneplot to obtain the raw data and basic graphs and tables. This report summarized the results of the cone penetration testing, including the highlighting of any significant variations. A more comprehensive evaluation of the data was performed using a proprietary software named GeoLogismiki CPeT-IT (CPeT-IT). The CPeT-IT software has the advantage of being able to combine similar soil layers and produce a summary table of estimated soil properties for these layers. No warranty is provided on the interpretations given by the GeoLogismiki software and the results are provided for reference purposes only. The 25 CPT borings were completed to depths of 15 to 60 feet below ground level (ft bgl). Suspected building rubble was encountered in one of the holes at 10 ft bgl. In another boring early refusal was encountered at 20 ft bgl. This test hole was reanchored the following day and a depth of 51.5 ft bgl was obtained. Dissipation tests were performed in three soundings (SW-03, SW-09 and SW-11). Each sounding ran continuously without disturbance or interruption and the data collected was considered to be accurate and representative of each respective location. Sample CPTU profiles created using CPeT-IT software are provided below. The materials presented mainly as mixes of sands, silty sands and sandy silts with rare clayey layers. Low tip resistance in C-01 between 4.607 ft and 6.067 ft bgl caused negative qc readings to be recorded within that section and hence no soil type is shown on the Soil Behavior Type (SBT) plot between those respective depths. The groundwater levels (GWL) were measured when possible and recorded. The GWL depths were entered manually on all the sounding profiles. The water table was not measured on five of the soundings due to the holes closing after retracting the rods, due to running sands.