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Subsidence Investigation SDII Project Number:3023547 Quiros-Martina:z Residence-Zephyrhills,Florida 2.0 GEOLOGIC AND GEOTECHNICAL EVALUATION Site-specific �;eologic and geotechnical evaluations were used to help characterize subsurface conditions at t.�e site. Geologic/geotechnical field tests performed at the site included: ❑ Grounr,i penetrating radar(GPR)survey ❑ Hand��.uger(HA)borings ❑ Standa:rd penetration test(SPT)borings Results of thE°: field tests are provided in this section. Note that the order of numbering or lettering of field tests is arbitrary and not indicative of priorities or the sequence of the investigation. The procedurf:s used far field sampling and testing were in general accordance with industry standards of care and established geologic and geotechnical engineering practices. Appendix A cites and discL�sses those methods. 2.1 Groumd Penetrating Radar Survey Results SDII acquired GPR data around the perimeter of the structure, as well as inside the home. The exterior GPR �,urvey was performed along transect lines established on an approximate 10-foot by 10-foot grid. The interior GPR survey was performed in accessible areas within the home. Figure 3 shows the locations of the GPR transect lines. Equipment settings for the GPR survey are indicated iri Table 2. GPR survey results indicated the presence of one set of reflectors on the GPR data. This reflector set was nearly horizontal and apparently continuous across a majority of the project site. This reflector set appears to correspond with an abrupt change in soil conditions, such as soil type or moisture conte�zt. The depth to this reflector set ranged from 6 to 7 feet below land surface(bls). Review of th:, GPR data indicated that there were no subsurface anomalies such as are commonly associated with sinkhole activity within the surveyed areas of the project site and above the limit:s of radar wave penetration. 2.2 Hand��►uger Boring and Push Penetrometer Sounding Results Four hand au�;er borings (HA-1 through HA-4) were advanced near the foundation of the structure to observe soi( conditions and collect soil samples. The locations of the borings are shown on Figu�^e 4. Hand auger boring logs are provided in Appendix B. The hand auge:r boring data indicated that the soils at the site were consistent with the mapped soil type as shc�wn in the County soil siirvey(Section 1.5), encountering poorly graded sand with silt and sand(SP-SM and SP). The water tabl�;;was not encountered in the hand auger borings. 2-1