HomeMy WebLinkAboutSoil Report revsied Allterra 11.1.20213866 PROSPECT AVENUE • SUITE 9 • WEST PALM BEACH, FLORIDA 33404 • (561) 881-1939
4 November 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
8024 South Ocean Drive, Diamond Sands Lot 17, Jensen Beach, Florida
Allterra Engineering & Testing respectfully submits this addendum to its report of
geotechnical services for the subject project dated 20 August 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 October 18, 2021, and entitled Design Wave
Condition, 8024 S. Ocean Boulevard, Jensen Beach, 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 20-August-2021 geotechnical services report to its design model. Allterra estimated
the following capacities for 14-inch auger -cast piles installed to approximately 29 feet
below surface grade (approximately 20 feet below scour grade).
Notes: CULTIMATE = ultimate compressive load capacity.
CALLOWABLE = allowable compressive load capacity.
CULT/CALLOW — CULTIMATE / CALLOWABLE
Uplift Resistance = (weight of pile + skin friction)/1.5.
Kips = 1000 pounds.
Considering the breaking wave crest elevation of +15.5 feet NAVD and FF elevation
from site plans, Allterra assumed a low structural floor beam at +19 feet NAVD
(approximately 20 feet above eroded grade). Model lateral displacements for fixed -toe
fixed -head piles installed to approximately 29 feet below surface grade (approximately
20 feet below scour grade) are summarized in following table:
Pile Diameter Single -Pile Displacement 4-Pile-Group Displacement
Addendum to Geotechnical Services 1 8024 South Ocean Drive, Jensen Beach, FL
4 November 2021 21 - 179
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 (14-inch
diameter) shall be reinforced with five full -depth number-5 steel bars and number-3 ties
spaced not more than 16 inches on -center. Piles (16-inch diameter) shall be reinforced
with seven 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.
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.
Yours truly,
Allterra Engineering & T�gstiih 11 t /1//
Registry No. 9139 ��� ,�,.�,..'.400'���
3 rya. sssso .�
Wendell Rodgers,
Principal EngineeP •o
FL Lic. No. 55960 �®' STATE OF tpW
C: Rob Agsten, PE SS'®NAI. ���
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Addendum to Geotechnical Services 2
4 November 2021
This item has been digitally signed
and sealed by Wendell K. Rodgers,
P.E. on the date adjacent to the seal.
Printed copies of this document are
not considered signed and sealed and
the signature must be verified on
electronic copies.
8024 South Ocean Drive, Jensen Beach, FL
21 - 179