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Sinkhole Geotech, Inc. Geotechnical &Structural Consulting 21859 State Road 54, Lutz, Florida 33548 HEN-S D : N• RIN 1NG: Y` TE E ?- _W HOUL ,U D,E.R N S _S. M,.BE::.U,S D There is a variety or reasons when underpinning should be usea. when buildings are on - unpredictable land with voids, there is often a possibility that the foundation will become unstable. In this situation, underpinning may be necessary. Here are a few examples of situations that would require underpinning: • Structure is not even: re-leveling the structure • cosmetic/structural cracxs: closing or wiae cracxs causea by excessive settlement • Soils have changed or cavities were created: bypass weak soil layers • Soils have not been completely identified before construction began: pre- construction underpinning • The foundation may no longer be strong or stable enough for support of the structure: foundation augmentation • The structure's purpose may have changed: meeting the weight increase on the foundation ® Structure needs additional foundation capacity to footings or mats with too little -bearing-capacity (building movement or ground consolidation is excessive) • Distressed or undermined Structure needs support: a catastrophic event (e.g. erosion,landslides,burst pipes,mine subsidence, etc.) • Adding load capacity to an existing foundation system to accommodate a seismic retrofit or addition of new structure,building stories, etc. • Cost considerations: homeowner preference ® . In the �,outneast rroperty [acquisitions Property, the underpin piers were nyarauiicaiiy driven down into the underlying soils to refusal or a pressure that was appropriate to avoid damaging the structure based the condition of the foundation at each location. The plan utilized 25 piers. However, piers no. 2 and 7 were eliminated for physical obstruction (to avoid cutting the very deep and thick slab in the front). The pier depth ranged from 13 to 4kU ieM LU ieeL UtUOW iUucivaLiUii. The jacking of each pier was monitored and terminated at a pressure that was appropriate to avoid damaging the structure based the condition of the foundation at each location. All piers were jacked to a pressure up to 3,500 psi, which provides more than 24,000 pounds of foundation support per pier. When the piers reached the ultimate support depth, each underpin bracket was secured to the pressure pier with 1/2' pin. The jacking depth and pressures of each individual pier are presented in tabular form in the appendix; of this report. s in conclusion, to tree best of our belier or xnowledge, mustang Homes nas completed this - piers installation in accordance with applicable standard practice and the foundation has been stabilized and habitable at this time. Therefore, it is also our opinion that there is no i Southeast Property Acquisitions Property Prniart Nn •CGT-F1RM A1If1 - Page 2 of 3