DRILLED SHAFT / BORED IN PILE INSTALLATION

New Brunswick Fitness & Wellness PlazaNew Brunswick, NJ

Presentation to:ADSC Northeast Chapter

Holiday Inn, Clark, NJNovember 30th, 2012

Presentation by:Jeffrey B. Ayres

Moretrench American Corporation

PROJECT OVERVIEW

• Proposed Construction:• Fitness Center• Supermarket• Parking Garage

• Owner• City of New Brunswick

• General Contractor• Joseph Jingoli & Sons,

Inc.• Structural Engineer

• PS&S• Foundation Contractor

• Moretrench

PROJECT OVERVIEW

• Scheduling / Coordination• Difficult Schedule• No relief in schedule

when schedule slid• Additional subs added

when schedule slid

MTAC CONTRACT WORK – DRILLED SHAFTS

• 77 Total Drilled Shafts• Provide support for

new column loads• 39 @ 3’ diameter

• Reinforcing dowels • 38 @ 6’ diameter

• Reinforcing dowels• Anchor bolts

(precast connection)

• Average drill length: 30’

DRILL RIG (DRILLED SHAFTS)

• Soilmec SR-65• Hydraulic Rotary Rig• 22,500 mm (~74’) mast

• Equipped with:• Self Handling Counterweight• Kelly Drilling System• Drilling Mate System

• Actively monitor drill depth, crowd pressure, mast verticality, pump pressures, and more

DRILL RIG (DRILLED SHAFTS)

• Bottom of Mast Clearance• Cable system feed on back of mast• Enough clearance for casing

“spinner”

WHY SOILMEC?

MTAC CONTRACT WORK – BIP’s

• 246 Bored In Piles (BIP’s)• Provide support for new

slab• 18” Diameter• 6 x #6 reinforcing cage

substituted with #18 grade 75 threadbar

• Average drill length: 20’

DRILLING EQUIPMENT (BIP)

• Bauer RTG RG 19 T• Universal Piling Rig• Up to 78’ Mast Height

• Equipped with:• PIR (Pile Installation

Recorder)• Actively monitor drill

depth, grout volume per 5’ increment, and more

MATERIAL / EQUIPMENT SUPPLIERS

• Soilmec SR-65• American Equipment & Fabrication,

East Providence, RI • Bauer RTG RG 19T

• Moretrench owned, purchased from Posillico, Inc.

• Temporary Casing• Favor Steel & Fabricating,

Bessemer, AL• Drill Tooling

• Jeffrey Machine, Birmingham, AL• Concrete

• Clayton Concrete, Edison, NJ• Rebar

• Barker Steel, Avenel, NJ

LOGISTICS

LOGISTICAL ISSUES

• Existing Overhead Powerlines• Existing Robert Wood Johnson (RWJ) Building• Existing Utilities• Northeast Regional Amtrak Line

EXISTING OVERHEAD POWERLINES

EXISTING OVERHEAD POWERLINES

EXISTING OVERHEAD POWERLINES

EXISTING OVERHEAD POWERLINES

RWJ BUILDING DEMOLITION

Existing RWJ Building

RWJ BUILDING DEMOLITION

RWJ BUILDING DEMOLITION

Mobilized prior to demolition

22 caissons unavailable during demolition

Obstructions / Utilities encountered beneath building footprint while drilling

RWJ BUILDING DEMOLITION

EXISTING / NEW UTILITIES

AMTRAK PROXIMITY

• Required to be 15’ minimum between mast & edge of Amtrak line

DRILLED SHAFTS

DRILLING PROCEDURE (3’ DRILLED SHAFTS)

• 48” diameter starter can for top 5’

• 42” diameter “inner” can to top of rock

• Socketed into weathered shale

• Visual inspection performed by PS&S

DRILLING PROCEDURE (6’ DRILLED SHAFTS)

• 87” diameter starter can for top 5’

• 78” diameter “inner” can to top of rock

• Socketed into weathered shale

• Visual inspection performed by PS&S

6’ DRILL TOOLING

3’ DRILL TOOLING

Soilmec equipped to switch between both 3’ and 6’ diameter tooling easily

REINFORCING CAGE / CONCRETE

• 26 x #11 bars per 6’ caisson• 10 x #9 bars per 3’ caisson• Cage placed with drill rig or crane

REINFORCING CAGE / CONCRETE

• Top of reinforcing cage @ 3” below top of caisson (minimum coverage of reinforcement)

• Water removal (hydraulic pump) & shallow depth permitted end dumping of concrete

DOWELS

• Issues Faced:• All 77 caissons received either dowels or anchor bolts

• Connection to grade beam, column, etc.• Drilling grade consistent at ~ elevation 47• Top of caisson elevation varied from elevation 47 to elevation 40• Drilling / epoxying dowels into 6’ shafts was not permitted

• Solutions:• “Wet-Set” dowels for 6’ shafts using premade wooden templates• Drill / epoxy any remaining dowels once top of caisson is exposed

DOWELS

• More than a dozen different dowel patterns• Up to 7’ depth below drilling grade (worst case scenario)

DOWELS

ANCHOR BOLTS

• Issues Faced:• Anchor Bolt location and embedment in top of drilled shafts were

critical, with nearly negligible tolerances• Solution:

• Per the engineer, pour shaft concrete 3’ below top of caisson (cold joint).

• Place 6’ corrugated pipe around top of shaft• Set template at correct elevation and plan location• Pour remainder of concrete• Monitor location of template before, during, and after pour

ANCHOR BOLTS

• Left: 6’ Diameter Caisson with Concrete 2’-3’ low• Right: 6’ Diameter Corrugated Pipe

ANCHOR BOLTS

• Left: Typical Anchor Bolt Template• Right: Placement of Anchor Bolt Template at exact elevation prior to

pour

ANCHOR BOLTS

ANCHOR BOLTS

ANCHOR BOLTS

ANCHOR BOLTS

• Left: Finished Anchor Bolt Shaft• Right: Precast Column @ Anchor Bolt Shaft

BORED IN PILES (BIP’s)

DRILLING PROCEDURE (BORED IN PILES)

• 18” Diameter Continuous Flight Hollow Stem Auger• Advanced 5’ below top of first rock encountered or to auger refusal

• <1’ / minute • Once tip reached, sand-cement grout pumped through auger• 115% of theoretical volume (measured by PIR & stroke count)• Slow positive rotation maintained during withdrawal

DRILLING PROCEDURE (BORED IN PILES)

• Upon grouting completion, pile top protector placed into hole (left picture)

• Top of Pile (grout) elevation reached by removing excess grout from top• #18 Grade 75 Threadbar installed full length (right) along with 4 x #4

bars with 90 degree bends• Average Production – 15 to 20 / DAY

BEFORE

AFTER

NEW BRUNSWICK WELLNESS PLAZA

QUESTIONS?