PJ Edwards & Co Ltd Innovations in CFA Piling

Conor Smith 4th Nov

1. About PJ Edwards & Co Ltd

2. Our Resources & Disciplines

3. Our Plant & Equipment

4. CFA Plunge Columns

5. City Centre ODEX Piling

6. High Torque Piling in Rock

7. Air-Assisted CFA Piling

8. River Dam Anchor Installation

9. Raking Buttress Contiguous Wall

10. Secant Walls – what to expect

11. PJ Edwards & Co Ltd next rig arrival

12. Questions

Agenda

PJE & Company Ltd

• Founded in 1972

• Operating in Ireland and United Kingdom

• Specialist piling & ground engineering sub-contracting company

• Noted for technical excellence and performance

• Regularly acting as PSCS as well as Sub-contractor

PJE & Company Ltd

• Regional spread throughout the UK and Ireland

• We Undertake ~200 contracts per year

• 80 employees, all directly employed

• Own extensive plant fleet with supporting plant maintenance workshops and fabrication/ manufacturing facilities

PJE & Company Limited

Range of Disciplines

• All types of Large & Small scale

Continuous Flight Auger Piling (CFA)

From 350mm to 1200mm in diameter

Up to 30m deep

• Rotary Pneumatic Piling (ODEX)

• Rotary Piling

• Anchors, Head Blocks & Mini-piling

• Restricted Access piling

• Guide-walls & Capping Beams

• Propping & Rig Attendances

PJE & Co Ltd Profile - Plant Resource

PJE & Co Ltd

Plant Resource

2 Nr

P135

3 Nr

P150

2 Nr

P140

2 Nr

P90

1 Nr

C26

2 Nr

Mait

Overall height [m] 30.37 33.76 30.00 26.80 25.54 23.90

Operating weight [t] 69.40 80.0 57.0 45.0 60.0 80.0

Torque (T) [kNm] 332.6 268.5 180.0 97.0 142.0 260

Extraction force (EF) [kN] 110 110 60 46 60 200

Main winch line pull [kN] 920 680 520 280 450 240

Auxiliary winch line pull [kN] 50.4 70 32 20 60 180

Maximum bore depth [m] 26.5 30 26.5 24 26 80

Maximum bore diameter [mm] 1200 1200 1050 800 1200 2600

In addition to the above “Large” Diameter Piling, we have a range of ODEX Hammers for rock boring range from 200mm to 640mm in diameter and 7 Nr 1500 cfm compressors

In addition to our range of “large” Diameter Piling Equipment We have 3 Nr Anchor Rigs and 4 Nr Mini-piling rigs for restricted access piling

CFA Plunge Column Piling at 1 Ballsbridge Client: Comer Bros Contractor: Glenbrier Engineer: Bakkala Consulting Engineers

Specialist Piling Contractor: PJ Edwards & Co Ltd Address: 1 Balls Bridge

Program: Dec 2013 to Feb 2014

Project Outline: Secant Wall & Plunge Columns to facilitate top down construction of 4 level Basement

Secant Wall • 450 linear meters of Guidewall • 325 Nr 900mm diameter High Torque CFA Female piles up to 9m deep (up to 2m into Rock) • 325 Nr 640mm diameter ODEX Male Piles – 12m deep (5m into rock) • To facilitate excavations up to 8m deep for double basement dig

Plunge Columns • 105 Nr 640mm ODEX Piles 17.5m deep with 305 X 305 X 240 UC – with C40/50 Concrete • 27 Nr 640mm ODEX Piles 11m deep with 305 X 305 X 240 UC – with C40/50 Concrete • To facilitate excavations for up to 4 levels of basement below ground

What is ODEX Piling

• 2 stage process to form the pile – best suited to forming piles in rock where conventional CFA piling would not be possible

• Stage 1 is where the ODEX Hammer is used to hammer thru the overburden and into the rock to the desired founding levels to form the socket that would not be possible with CFA piling (no concreting involved)

• The bore is backfilled with drill cuttings and awaits the pile installation • When a sufficient number pile positions have had the socket formed, stage

2 of the process can be carried out • Stage 2 is where the pile is installed using conventional CFA piling

techniques, it requires minimal effort and no heat generation and inflicts little or no time lag in the concreting process, which helps pile jointing in secant walls, cage installation in bearing piles and accuracy in Plunge Column work

Example of A secant Wall using ODEX Piling Methods

Plunge Column Installation at 1 Balls Bridge

Installation Tolerances to Consider • Plan Position • Level • Verticality • Rotational Tolerance

Installation Tolerances we undertook To Provide: • Plan Position – 75mm • Levels – within 50mm • Verticality – 1:150 • Rotational Tolerance – didn’t Matter

Installation Tolerances we achieved: • Plan Position – 50mm • Level – within 25mm • Verticality – 1:150 to 1:200 • Rotational Tolerance - +/- 15 Degrees

Fabricating the Plunge columns

Achieving the Plunge Column Tolerances

1. Being in control of the fabrication of the caged columns

2. Working with the Concrete supplier to have a mix with sufficient workability life to permit plunge column installation

3. Using the ODEX piling system which guarantees that all the hard work and heat generation is realised before the CFA piling operation commences – This in turn virtually ensures that the concrete remains in a workable state for the plunging activity

4. Good Setting –Out Control – accuracy or boring to within 50mm

5. Vigilant Supervisors, Rig Operators and Banksmen

6. Continual Engineering checks as columns are being installed

7. Ready to re-bore in the event of early refusal

Project Performance

• No NCRS on the Wall or Plunge Columns

• 2 Re-bores out of 127 Plunge Columns

• No remedials required to Wall or Plunge Columns

• All Core works complete within 10 weeks using 4 piling rigs – 8 weeks shorter than other programmes offered to the client

• Basement excavation complete Summer 2015

City Centre ODEX Piling

Potential Concerns

1. Noise

2. Vibration

3. Dust & Debris

Noise management

• 85 dBa for ODEX & 75 dBa for CFA piling

• The surrounding environment has a part to play

• Manage expectations – visit ODEX sites in advance for familiarisation

• Implement a monitoring regime

• Plan works on site to facilitate noise sensitive elevations

• Last resort - implement curfew 8-10am for Hotel works

Vibration (minimal concern <2mm/s ppv)

Dust And Debris

Dust and Debris • Monitor • Use debris netting screen if required – However Shroud curtails 95-98%

of debris • Naturally occurring moisture in the ground reduces/eliminates dust • Housekeeping on the site boundaries

High Torque CFA Piling In Shallow Rock

• Rock within 4 to 5m of pile cut off level

• High loads - 150/175t for 600mm diameter piles or 100t for 450mm

• Clay overlying rock weathered to varying degrees

• High Torque CFA equipment and heavy duty digging tools permit penetration into rock to provide low settlement and consistent performance under load

• Experienced Personnel and computerised logging of pile installation important

• Continuous review of piling records and ground conditions essesntial

Typical Pile Log for CFA piling into Rock At shallow depths • Pile Circa 500mm into rock • 2m in Dense Dublin Boulder Clay • Additional Over-break at start • High Concrete over break for short piles

Project Summary • 500 piles in 4 weeks in Summer 2015 • 450mm diameter average 4m deep • All 100T SWL • High Concrete over break for short piles • 7 Load tests – 20 Dynamic Tests • Excellent consistency in results • Excellent correlation between Load tests

and Dynamic test

Air Assisted CFA

• Being Introduced/Trialled by PJ Edwards & Co Ltd over last year and initial results are encouraging

• Air Assisted CFA is blowing air down the concrete line/stem of the auger which assists in getting the pile arisings out of the bore

• The piling becomes more efficient

• Less heat generation and interference with concreting

• Less wear & tear on equipment

• Can dig deeper and with larger diameters

• Don’t need large volumes of air

Initial Trials – Broadstone Dec 2014 • Brought about by necessity • Digging 18m deep 1200mm CFA piles in

boulder clay was asking a lot from the rig, taking 45mins to 1 hr to bore – which resulted in the pile positions being prebored as concrete was losing workability

• Trial posed to see if it would assist • Air line connected to where the concrete

is pumped • Pile dug from 4m down with circa 500 cfm

compressor on low revs • Pile boring time halved to under 30 mins • Easier on time, fuel and the equipment

Leixlip Anchor Installation Oct 2015

Liexlip Anchor Installation

Alternative Solution to 1500mm diameter contig wall • Proposal made in conjuction with BLP for 1200mm

Buttress solution • 1200mm wall piles 18m deep • Buttress piles 1200mm in diameter 17m deep raked at

7 Degrees • 14B32s full depth

Broadstone Buttress Contig wall

Expectations

Secant Walls – What to expect

• Secant walls are not perfect - allow for tolerances as these can have an impact on the follow on liner wall

• Allow for equipment access and clearance between party walls

• The ground is not perfect – expect bulges in places

• Put all the guidewall in at the start

• Expect damp patches and also some moisture

• Secant wall do not stop water rising up from fissure rock

Recent Plant Acquisitions

• Recent Equipment Acquisitions

• P135 commissioned into the fleet in Aug 2015 – carries on board the capability to do Cased CFA piling

• P240 Arriving Jan 2015

Questions?