1DFI 37th Annual Conference

Cased Auger Piles (CAP): An Effective Piling Solution

Federico PagliacciSoilmec S.p.A. Cesena Italy

Cased Auger Piles (CAP): an effective piling solution

Continuous Flight Auger piles (CFA) are performed by means ofa continuous flight auger assembled on a central hollow pipe.

Upon completion of the boring operation, the auger is extractedwhile the concrete is poured throughout the internal hollowpipe.

The steel reinforcement cage is finally lowered into the freshconcrete.

Piles with a maximum diameter of 55 in to a maximum depth of108 ft can be performed.

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CFA advantages: The method can be utilised in a wide range of cohesive and

cohesionless soils, with or without the presence of a water-bearing stratum and without bentonite fluid as wall support.

The technology does not produce shocks, vibrations, noise, thus allowing to work in urban areas.

The minimum required equipment (the rig plus the concrete pump) allows to minimise the job site installation plant and to operate in very restricted areas.

An industrial production of 950 1300 ft/day

CFA limitations:Difficulty of penetrating hard layers and cross strata with cobblesand boulders.Difficulty of maintaining the required verticality in coarsematerials with cobbles.

Cased Auger Piles (CAP): an effective piling solution

Auger rotary

Casing rotary

Cased Auger Piles (CAP) are performed by means of acontinuous flight auger housed inside a steel casing.

Auger and Casing are driven by two independent rotaries. Piles with a maximum diameter of 47 in to a maximum depth of

88 ft can be performed. The maximum cased depth is of 69 ft.

3Cased Auger Piles (CAP): an effective piling solution

Cased Auger Piles (CAP) have been first developed to constructsecant piles to form a continuous, watertight diaphragm wall.

Construction sequence: primary and secondary piles withproper overlap.

Different possible option for steel reinforcement solutions.

Cased Auger Piles (CAP): an effective piling solution

The excavated material is loaded onto the flight to betransported from the top of the casing to the base of the rigthrough a Spoil Chute.

4Cased Auger Piles (CAP): an effective piling solution

Type of casing, auger tips and type of teeth depend on soilconditions and soil abrasiveness.

Drill tools available to drill into rock with UCS up to 12,000 psi.

Guide Walls are of paramount importance to ensure the properalignment of piles and to guide the casing at the surface.

Cased Auger Piles (CAP): an effective piling solution

Equipment

SR-70 SR-80 SR-90 SR-100

Max pile depth 77.1 ft 77.1 ft 82 ft 91.9 ft

Max caseddepth

57.5 ft 57.5 ft 62.3 ft 68.9 ft

Max diameter 31 in 31 in 39 in 47 in

Operative weight

196,430 lb 201,712 lb 255,734 lb 330,690 lb

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Concrete quality

Concrete aggregate: fine gravel of max size 0,7 in. Cement content: 20 28 lb/ft3. Slump: greater than 9 in (cages length up to 60 ft). Pie diameter: greater than 25 in (cages length up to 100 ft).

S5 Concrete

Slump > 9 inSSC Concrete

Pie diameter >25 in

Cased Auger Piles (CAP): an effective piling solution

Cages have to be properly manufacturedand well assembled (preferably welded).

The external dimension has to bemaintained smaller than for standardbored piles, to grant a sufficient cover.

A conic shape at the bottom of the steelcage is obtained by adopting a bottom ringsmaller in size than the standard ones.

6Cased Auger Piles (CAP): an effective piling solution

A computerised system allows, through a touch screen monitorinto the operators cab, to monitor and download all the CAPprocess parameters, both during drilling and concreting phases.

Drilling phase:The rotaries speed/torque,The auger and casing pull-down force,The auger and casing tips drilling depth.

Extraction phase:Concrete pressure and delivery.The auger and casing pull-up force.The auger and casing tips elevation.

Cased Auger Piles (CAP): an effective piling solution

Railway network (Palermo Italy) Modernization of the railway network in the Palermo area. Over 19 miles of railroad extension 12 miles crossing urban

areas. 17 stations and 22 stops. 76,000 ft of secant piles.

7Cased Auger Piles (CAP): an effective piling solution

Railway network (Palermo Italy) Drilling was carried out at a depth of 82 ft, pile diameter was

36 in and 3,5 in was the overlapping. A deviation from verticality of less than 0,5% had to be

guaranteed. An average production of 3,5 piles/shift has been achieved. The most powerful rig on site had an average production of 4,3

piles/shift. Industrial production rate: 287 353 ft/day

Cased Auger Piles (CAP): an effective piling solution

Railway network (Palermo Italy)

8Cased Auger Piles (CAP): an effective piling solution

Railway network (Palermo Italy) Several underground passageways have been constructed, as

part of the citys General Plan to smooth both road and railtraffic.

Cased Auger Piles (CAP): an effective piling solution

Merano Ring Road Project Italy

Merano Municipality planned in 2010 the construction of a 2,5miles long underground ring road to solve the problem of thetransit of heavy traffic through the city.

A cut and cover tunnel was constructed in the west portion; atunnel boring machine was adopted for the east portion of thetunnel, after the railway station.

The tunnel is 35 ft large and 16 ft high.

Section 2 39 ft diameter tunnel

Section 1 35 ft large tunnel

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9Cased Auger Piles (CAP): an effective piling solution

Merano Ring Road Project Italy

24 in diameter pile: excavation 70 min; concreting and steelcage 20 min.

47 in diameter pile: excavation 120 min; concreting and steelcage 30 min.

Industrial production rate: 259 430 ft/day

Cased Auger Piles (CAP): an effective piling solution

Merano Ring Road Project Italy

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Cased Auger Piles (CAP): an effective piling solution

Merano Ring Road Project Italy

Cut & Cover Tunnel

Railway station junction and exit

Cased Auger Piles (CAP): an effective piling solution

ConclusionCAP advantages

CAP does not induce disturbances toadjacent structures and it prevents soildecompression.

CAP does not induce vibrations, shocks,noise

CAP grants verticality in the range of 0,5%.

CAP limitations

CAP needs a more expansive concrete. CAP steel reinforcement requires more

attention in assembling and lowering.

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Thank you.

Federico PagliacciSoilmec S.p.A. Cesena Italy

Cased Auger Piles (CAP): an effective piling solution