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IMPORTANT ITEMS OF SECTION 49-3: CAST-IN-PLACE CONCRETE PILING(And How the ADSC WCC and Caltrans has worked together to improve these
Specifications!)
Ray Fassett
ADSC WCC PAST PRESIDENT
Condon-Johnson & Assoc. Inc
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For Your Information:• 49-3.02 CAST-IN-DRILLED-HOLE (CIDH) PILE
– Caltrans is the only DOT that uses this description for a Drilled Shaft.
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• Special Provisions will update the 2010 Standards.
• Amendments to the Standards also exist. Remember to stay current!
• These specifications describe how the work is to be built. They still require clarifications prior to and during construction.
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• 49-3.02A(3)(b) Pile Installation Plan– Most Important Submittal for CIDH work.– Defines the Installation Process.– Should cover all aspects of the work.– Should be reviewed based on the required
content.• But is it necessary to cover things that don’t apply?• List is redundant, should it be covered multiple times?• Is it easier to follow a Submittal that follows the list?
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• 49-3.02A(4)(b) Preconstruction Meeting– Needs to be held after the Pile Installation Plan
has been submitted and reviewed.– Provides an opportunity for the Inspection Staff to
discuss with the contractor how the work will be performed.
– Should include most people listed in BCM 130-20.0
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• 49-3.02A(4)(b) Preconstruction Meeting (Cont.)– Should discuss shaft entry procedures.– Should discuss tie-off procedures and access to
the shaft for Inspection Personnel. – Will Caltrans log the shaft?
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• 49-3.02A(3)(c)(g) Mitigation Plan– ADSC Standard Mitigation Plan
• Came out of ADSC WCC’s and Caltrans’ Substructure Committee as a way to mitigate the time it takes to review a repair procedure. Over 90% of all Anomalies can be mitigated with this Plan.
• Began in 2005, published in 2007.
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• 49-3.02C(2) Drilled Hole– Amended 7-19-13 to provide a horizontal
tolerance. • This is a product of the Caltrans ADSC WCC
Substructure Committee.• Allows the larger of 1/24 of pile diameter or 3” in a pile
group.• Provides tolerance in a Type II pile by way of minimum
clearances between column and CIDH reinforcing.• For Type I pile, needs to be accurately placed or need to
use the tolerance in the concrete cover.
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• 49-3.02C(4) Reinforcement– Amended 1-20-12 to require minimum of 3”
concrete cover.• This is a product of the Caltrans ADSC WCC
Substructure Committee.• Is a compromise to allow for the larger cover to be used
to align the CIDH reinforcing cage into the correct location.
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• SIDE NOTE ON REINFORCEMENT: – not everything that pertains to this work is in Sect. 49.
• California Amendments to AASHTO LRFD: Rebar Spacing
• 52-1.03D Placing– Section entitled “For column and pile bar reinforcing cages
measuring 4 feet in diameter and larger”• These Tie requirements were a product of an ADSC WCC / AGC /
CRSI and Caltrans meeting held back in 2009 to discuss the safe handling of rebar cages.
• Later confirmed by the UNR Research on Column Stability
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• 49-3.02B(8) Spacers– Amended 1-20-12 to allow the use of plastic
spacers.– Product of a request from the ADSC WCC
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• 49-3.02A(4)(d) Acceptance Testing– (i) General:
• Is water allowed in the tubes during testing?
– (ii) Vertical Inspection Tubes: • Standardized by the Substructure Committee.• Requires reinforcing to be installed non-uniform but still
symmetrical (provided equal number of tubes to the number of vertical bars) to provide proper clearances to pvc.
– (iv) Rejected Piles, Anomaly Deduction• ADSC WCC and Caltrans partnered on the “new” deduction
table.
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• 49-3.02B(4) Permanent Steel Casing• 49-3.02C(5) Permanent Steel Casing
Installation• 49-3.02C(6) Construction Joint
– When is CMP Casing Acceptable?• When used in conjunction with a Construction Joint?• Why are construction Joints for Type II piles
mandatory?
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• 49-3.02B(4) Permanent Steel Casing• 49-3.02C(5) Permanent Steel Casing Installation• 49-3.02C(6) Construction Joint
– (Cont.)– 49-3.02B(5) Grout
• Is lean concrete an acceptable backfill around permanent casing?
• Amended 7-19-13 to allow neat cement grout as backfill.
– this works for a small annulus around casing.
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• 49-3.02A(2) Definitions– 1-20-12 Amendment Defines a “dry hole”
• Product of a request from the ADSC WCC
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• 49-3.02B(6) Slurry– Know the difference between “recirculated” and
“replaced” and why one might be better than the other.
– Caltrans requires the use of slurry when you cannot dewater a shaft.
• When is it ok to use water as a slurry?– Full Length Casing?– Non-Slacking Rock?– What will the Specifications allow?
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QUESTIONS?
COMMENTS?
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