Geotechnical Investigation using Cone Penetration Testing (CPT) in a parcel of land for a new development in Parish, FL

Geotechnical Investigation using Cone Penetration Testing (CPT) in a parcel of land for a new development in Parish, FL

ATI Geologica completed five (5) Cone Penetration Tests to delineate soil stratigraphy and determine engineering parameters for a proposed development in Parish, FL. The tests were performed using a track mounted Geoprobe 7730DT anchored using two helical anchors. An electronic piezocone manufactured by Vertek was advanced at a rate of approximately 2 cm/s. The data was recorded using the Vertek DataPack and their proprietary data acquisition software. The raw data was then processed to obtain graphs of cone resistance, friction ratio, pore pressure and soil behavior type. Additional data including estimated geotechnical parameters were also plotted and provided.

The original plan was for the five CPTs to evaluate conditions to a depth of 30 feet (ft). However, the tests were continued to depths of 32 to 37 ft because it was suspected during testing that the very dense, weathered limestone stratum (which was of primary concern) may have been below that depth.

Each sounding produced a continuous profile without interruptions. The data was of a high quality and considered to be accurate and representative of the geological conditions.

Results showed that the water table was at or near the ground surface, which was confirmed by above-ground observations. The materials are presented mainly as complex interbedding sands, silty sands and sandy silts with occasional clayey layers. Layers with suspected gravel were encountered in two of the soundings.

Data is captured continuously by the sensors inside the CPT and processed to determine the Soil Behavior Type. The results from one of the soundings are shown in the image below.