Project Number: AW-2225

Contract Number: TW-0839

December 1996

SPECIAL SPECIFICATION

SECTION 02350

[CAISSONS]{.underline}

[PART 1 - GENERAL]{.underline} [Page]{.underline}

1.01 Summary

1.02 Related Sections

1.03 Submittals

1.04 Quality Assurance:

1.05 Contractor Qualifications

1.06 Job Conditions

PART 2 - MATERIALS

2.01 Concrete

2.02 Reinforcing Steel

PART 3 - EXECUTION

3.01 Caisson Excavation

3.02 Concrete Placement

3.03 Reinforcing Steel and Dowels

3.04 Field Tests/Inspections

3.05 Field Logs

SPECIAL SPECIFICATION

SECTION 02350

[CAISSONS]{.underline}

# PART 1 - GENERAL

## 1.01 [SUMMARY]{.underline}

A. [Section Includes]{.underline}:

1\. Concrete Caissons

## 1.02 [RELATED SECTIONS]{.underline}

A. Section 03300 - Cast-in-Place Concrete

## 1.03 [SUBMITTALS]{.underline}

A.  Submit in accordance with the Conditions of Contract and Division 1
    Section "Descriptive Submittals", unless otherwise indicated.

B.  [Shop Drawings]{.underline}: Indicate by dimensions location of each
    portion of Work.

C.  Daily Caisson Report for each caisson, recording actual elevation at
    bottom and top, elevation of rock (if any), final centerline
    location at top, variation of shaft from plumb, result of tests
    performed, any unusual conditions, times of starting excavation,
    completion of excavation, inspection, testing and placement of
    concrete (include any delays in concreting and location of
    construction joints in shafts).

D.  Submit qualifications of Caisson Drilling Contractor for approval by
    Sandia National Laboratories (SNL) prior to start of caisson
    construction.

## 1.04 [QUALITY ASSURANCE:]{.underline}

A.  [Codes and Standards]{.underline}: Comply with provisions of
    American Concrete Institute (ACI) "Standard Specification for the
    Construction of End Bearing Drilled Piers" (ACI 336.1) , and as
    herein specified.

B.  [Survey Work]{.underline}: Engage a registered surveyor or licensed
    Professional Engineer to perform surveys, layouts, and measurements
    of each caisson's horizontal axial location, shaft diameter, bottom
    and top elevations, deviations from specified tolerances, and other
    data as required.

## 1.05 [CONTRACTOR QUALIFICATIONS]{.underline} 

A. The caissons shall be installed by a Contractor experienced with the
type of caissons specified, with experience in similar ground
conditions. Submit a list of five (5) previous projects constructed
under similar conditions.

## 1.06 [JOB CONDITIONS]{.underline}

A.  [Site Information]{.underline}: The geotechnical investigation
    report is provided for the Contractor's information. It is expressly
    understood that SNL will not be responsible for interpretations or
    conclusions drawn therefrom by Contractor. The report is made
    available for convenience of Contractor and is not guaranteed to
    represent conditions that may actually be encountered.

B.  [Additional test borings]{.underline} and other exploratory
    operations may be made by Contractor at no additional cost to SNL.

C.  [Existing Utilities]{.underline}: Locate existing underground
    utilities by careful hand excavation before starting caisson
    excavation operations. If utilities are to remain in place, provide
    protection from damage during caisson operations.

D.  Should uncharted or incorrectly charted piping or other utilities be
    encountered during excavation, consult the SDR immediately for
    directions to procedure. Cooperate with SNL and utility companies in
    keep services and facilities in operation. Repair damaged utilities
    to satisfaction of utility owner.

# PART 2 - MATERIALS

## 2.01 [CONCRETE]{.underline}

A.  Comply with the requirements of Section 03300 unless indicated
    otherwise. The maximum size of aggregate shall be 1 ½".

B.  [Caisson Concrete]{.underline}: 3000 PSI at 28 days.

## 2.02 [REINFORCING STEEL]{.underline}

A. Comply with the requirements of Section 03300.

# PART 3 - EXECUTION

## 3.01 [CAISSON EXCAVATION]{.underline}

A.  [General]{.underline}: Excavate holes for caissons to required
    elevation as shown on drawings. Excavate holes for closely spaced
    caissons, and those occurring in fragile or sand stratas, only after
    adjacent holes are filled with concrete and allowed to set.

B.  [Construction tolerances]{.underline}: Locate centerline of caissons
    within the following tolerances:

C.  Permissible variation of location not more than 3" (76 mm).

D.  Shafts out of plumb, not more than 1.5% of length nor exceeding
    12.5% of shaft diameter or 15" (381 mm), whichever is less.

E.  Concrete cut-off elevation, plus 1" (25 mm) to minus 3" (76 mm).

F.  If above tolerances are exceeded, provide corrective construction to
    compensate for excessive eccentricity, as directed by the SDR.

C. Remove from building area all material removed from caisson
excavation in excess of fill requirements.

## 3.02 [CONCRETE PLACEMENT]{.underline}

A. [General]{.underline}: Fill caissons with concrete immediately after
inspection and acceptance by the SDR. Use protection sheets (cut out to
receive concrete) over excavation openings, extending at least 12"
beyond edge.

B.  Place concrete continuously and in a smooth flow without segregating
    the mixed materials. Provide mechanical vibration for consolidation
    of at least top 5-feet of each shaft.

C.  Place concrete by means of bottom discharge bucket, flexible drop
    chute, elephant trunk hopper or tremie. Use chutes or tremies for
    placing concrete where a drop of more than 5 feet is required, or
    pump concrete into place.

D.  Stop concrete placement at cut-off elevation shown, screed level,
    and apply a scoured, rough finish. Where cut-off elevation is above
    ground elevation, form top section above grade and extend shaft to
    required elevation.

E.  All concrete must be placed within eight hours of caisson
    excavation.

## 3.03 [REINFORCING STEEL AND DOWELS]{.underline}

A. Before placing, clean reinforcing steel and dowels of loose rust,
scale, dirt, grease and other material which could reduce or destroy
bond.

B. Fabricate and erect reinforcing cages in shafts as one continuous
unit. Place reinforcement accurately and symmetrically about axis of
hole and hold securely in position during concrete placement with
spacers specifically manufactured for holding reinforcing in drilled
holes.

C.  Use templates to set anchor bolts, leveling plates and other
    accessories furnished under work of other sections. Provide blocking
    and holding devices to maintain required position during concrete
    placement.

D.  Protect exposed ends of dowels and anchor bolts from mechanical
    damage and detrimental exposure to weather.

## 3.04 [FIELD TESTS/INSPECTIONS]{.underline}

A. [Inspection]{.underline}: When a suitable bottom is reached in any
caisson, no reinforcing steel or concrete will be placed until the SDR
has inspected it.

## 3.05 [DAILY CAISSON REPORTS]{.underline}

A.  A report for each caisson is required upon completion of each
    caisson.

B.  [Daily Caisson Report]{.underline}: Each report shall contain but
    not be limited to the following information:

C.  Caisson Designation.

D.  Date Started.

E.  Date Completed.

F.  Shaft Diameter.

G.  Top and Bottom elevations as actually placed.

H.  Amount of Concrete Placed.

I.  Amount of Obstructions (if any).

C. Upon completion of the report it shall be signed by the installer.
Submit six (6) signed copies to the SDR.

END OF SECTION