HomeMy WebLinkAboutAPPROVED G SOIL REPORT - Addendum DocuSign Envelope ID:AF9DC941-8708-4BB6-AF5D-8556CAEBB54E
E N G I N E E R I N G & T E S T I N G
3866 PROSPECT AVENUE • SUITE 9 • WEST PALM BEACH, FLORIDA 33404 • (561) 881-1939
26 May 2021
Phoenix Custom Homes
1760 Jog Road, Suite 120
West Palm Beach, FL 33411
Subject: Addendum to Report of Geotechnical Services — 3-Level Custom Home
4805 Watersong Way, Fort Pierce, Florida
Allterra Engineering & Testing respectfully submits this addendum to its report of geotechnical
services for the subject project dated 15 January 2021. This addendum revises conclusions and
recommendations about auger-cast pile capacity, load deflection, and design. This addendum is
Allterra's instrument-of-service provided for sole reliance and use by Phoenix Custom Homes. Third
parties may read this report for information purposes.
A digital copy of a memorandum dated May 20, 2021 entitled Design Wave Condition, 4805
Watersong Way, Ft. Pierce, St. Lucie County, Florida by Isiminger & Stubbs Engineering was
provided for Allterra's refence in performing its services. The memorandum presented information
on design eroded-grade elevation, breaking wave crest elevation, still water elevation, wave and
debris impact forces on square and round piles, and hydrodynamic wave forces
Allterra applied the memorandum's information and conceptual subsurface profile from the 15-
january geotechnical services report to its design model. Allterra estimated the following capacities
for 14-inch auger-cast piles installed to approximately 30 feet below surface grade (approximately
28 feet below scour grade).
Pile Diameter CULTIMATE CALLOWABLE CULT/ CALLOW Uplift Resistance
14 inches 190 Kips 76 Kips 2.5 122 Kips
Notes: CULTIMATE= ultimate compressive load capacity.
CALLOWABLE = allowable compressive load capacity.
CULT/CALLOW= .
Uplift Resistance = (weight of pile + skin friction)/1.5.
Kips = 1000 pounds.
Considering the breaking wave crest elevation of+15.5 feet NAVD, Allterra assumed a low structural
floor beam at +17 feet NAVD (approximately 18 feet above eroded grade). Model lateral
displacement for a single fixed-toe fixed-head pile was approximately 2 inches. For a file of four
fixed-toe fixed-head piles restrained in a common rigid beam, lateral displacement was
approximately '/2 inch.
For auger-cast piles, Allterra recommends:
Pile Materials. Piles shall be formed with minimum 4000 PSI grout placed under pressure as the
auger is progressively withdrawn from the borehole. Piles shall be reinforced with five full-depth
number-5 steel bars and number-3 ties spaced not more than 16 inches on-center. The structural
engineer shall determine the number and distribution of piles considering structural loads and
geometry. Piles shall be drilled 8 feet into rock or refusal (less than 1 foot/minute advance).
Addendum to Geotechnical Services 1 4805 Watersong Way, Fort Pierce, FL
26 May 2021 21-117
DocuSign Envelope ID:AF9DC941-8708-4BB6-AF5D-8556CAEBB54E
Pile Layout. The number and distribution of piles shall be determined by the structural engineer
considering project loads and geometry. Piles shall be spaced at-least 3 diameters center-to-center
to avoid group effect on stress distribution in the bearing stratum.
Pile-Installation Monitoring. Engage Allterra to monitor installation of piles. For auger-cast piles,
monitoring shall include:
1. Check pile layout for conformance to design foundation plan.
2. Observe field trial and calculate gout-pump factor.
3. Observe drilling of pile to verify target depths are achieved.
4. Observe grouting of pile bore to verify acceptable grout return.
5. Sample grout for compressive-strength testing.
6. Observe installation of reinforcing steel to verify full-depth penetration.
7. Test grout specimens to verify design compressive strength is achieved.
8. Calculate grout factors and summarize installation data for each pile.
9. Prepare report of work acceptance signed and sealed by Professional Engineer.
Please call the undersigned if one has questions about this report or needs other services.
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Yours truly, `��` �,L K. 40���i,�
Allterra EngineerU) ,>�
Certificate of Authc ZUrn 9139 This item has been digitally signed
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cuSigned by: +� NO. 55960 '•,N
and sealed by Wendell K. Rodgers,
* _ P.E. on the date adjacent to the seal.
23B3DAF44F... � Printed copies of this document are
Wendell Rodgers ' �=
STATE OF not considered signed and sealed
Principal Engineer'.��`�,' .,��oatiop.• ' ?; and the signature must be verified on
FL Lic. No. 55960 '�,�5'S*0NAL,�� �` electronic copies.
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Addendum to Geotechnical Services 2 4805 Watersong Way, Fort Pierce, FL
26 May 2021 21-117