PIANC UK Seminar Design Developments and Specification for Steel. Duncan Nicholson Arup Fellow 9/3/17 ICE London

Transcription

1 PIANC UK Seminar Design Developments and Specification for Steel Duncan Nicholson Arup Fellow 9/3/17 ICE London

2 Contents 1. Design Issues 2. SPERWall Edition 3 (2016) 1. Steel Sheet Piles (Section 14) 3. Steel Piling Group 4. Pre-augering examples.

3 Section B14 Specification Changes B14.1 General Hot rolled piles Cat 2 structures Interlock standards Cold formed Design for buckling etc B14.2 Project Spec Construction tolerances moved to B Water-tightness to basement grades B Pile Installation Tolerances - BS EN 12063;1999 Table 2 - Agree tighter tolerances but cost and practical implications. Built up environment press-in piles B Methods of Assisting Pile Installation Degree of water jetting /pre-augering depends on design assumptions and local sensitive buildings B14.5 Corrosion Consider at design to BS EN :2006

4 Section C14 Guidance Changes C14.1 General U-type sections Clutch slippage on NA - Use NAD to BS EN :2006. C Clutch sealant and seal welding Use Accelor Mittal Piling Handbook 2016 Chapter 2. C Pile Installation Panel driving requirements clarified Pile rolling tolerances effect layouts Press-in methods are virtually vibration free. C Methods of Assisting Pile Installation Pre-augering - use in hard ground or to reduce section size. Spoil heap similar to sheet pile volume. Pre-augering should not proceed too far in advance of piling. Where large soil volume removed prove conditions by SPT. Close to structures - Use CFA monitoring equipment to control volume loss. Water jetting can lead to flooding and heave to adjacent foundations. C Combi-walls Essential to have a good pile driving template frame. Drive with extreme care to achieve straightness. Avoid declutching the intermediate piles. C Crush Piling Avoid excessive soil removal to control ground settlement In harder material including weak rocks the soil removal can effect passive response.

5 Wall tolerances EN12063:1999 Table 2. Limited guidance for Combi-walls

6 Steel Piling Group The SPG Mission:- Contact John Powell for more information.

7 Work group B SPG - Work Groups Title Description Progress Completion Sustainability Recycling, re-use, embodied energy, environmental impact. Virtually complete Q C Innovation Steel Innovative - alternatives to concrete piles. Web page Q D Durability Sacrificial steel, ALWC, coatings, cathodic E F protection, new steel grades Current technology and reviews latest plant developments. Plant Development Thermal Piles Use of steel piles for thermal piles and Closed Ground Source Heat Pump (GSHP) systems. Complete Q Ist draft Q Draft paper Q H Tie Rods Standard Piling Details & Tied Wall details Complete Q I Ground Pretreatment Particularly pre-augering and water jetting techniques. J Re-use of steel Quality issues to Codes and Standards. piles Link with steel reuse and sustainability. K Case Studies Good selection on line, but need more. Ongoing L High Modulus Walls Now in new Steel Piling Handbook. 1st draft Q website See workgroup B New studies online Q Reference doc Q M Sealants In Steel Piling Handbook Reference doc Q3 2017

8 Giken Press-in Sheet piles with the Crush pre-augering.

9 Typical Cofferdam section 11.4 m +5.5mOD Deflection Monitoring Point +4.55mOD +4.5mOD Dock Silt Sand Fill -4.5mOD 13m -6.8mOD -7mOD -7.3mOD Lambeth Group -14.6mOD Thanet Sand -16.0mOD

10 Giken Press-in piles with Crush pre-auger Auger in enclosed casing Auger in enclosed casing Giken Rig Auger head is approx. 400mm ahead of sheet pile

11 800mm Auger Details Auger diameter is adjustable Auger teeth set at 800m opening.

12 CPT tests at crush location Very loose Debris in auger hole. Most of soil flighted to surface. Passive earth pressure support reduced.

13 Auger void filled with concrete CFA Air lift Option 1 CFA rig used to concrete Crush auger void. Option 2 Debris air-lifted from auger void Tremie concrete placed in void

14 Deflection (mm) Cofferdam Dewatering Performance Survey targets predicted displacement 230mm Inclinometer

15 Giken Press-in Tubes with Crush Pre-augering

16 Tie Back System Marine deck Anchor tie Interlocking Giken tube Silt Terrace gravel Harwich Formation - sand Anchor Piles (3m centres) Contiguous pile (1.05m) drilled through tubes. Thanet Sand Lambeth Beds - clay Lambeth Beds - sand Steel casing

17 Giken Tubes -1200mm with Crush Pre-augering Crush pre-auger to penetrate harder ground Two Giken rigs - pitching tubes. 95% achieving verticality tolerance of 1 in 150

18 Dock draining minor seepage Occasional slight seepage Grout sock protruding out of the clutch P-P connection grouted cells

19 Conclusions on Crossrail Giken interlocking tubes - 1.2m diameter Equipment available to all tenderers Tolerance - Better than +/- 25mm and 1 in 125 verticality Installed through cemented layers Auger worked Good programme Clutches - good water tightness Boring piles used for Crossrail durability Could have been steel?

20 Conclusions Long History of Steel Piling at Canary Wharf:- Phase 1 Steel Deck Piles (1980 s). Phase 2 to 4 S Pile Cofferdams - Hammers (1990 s). Blackwell Pl. BP1 S Pile Cofferdam Vibrators (2002). Blackwell Pl. BP3/4 S Pile cantilever Vibrators (2005). Riverside Giken Crush S Piles - next to JLE (2008). Crossrail Giken Tubes (2010). Noise and Vibration - now very important:- Wood Wharf Cantilever - Vibration / boring. Bank Street Cofferdam - Giken.

21 Conclusions on Crossrail Giken interlocking tubes - 1.2m diameter Equipment available to all tenderers Tolerance - Better than +/- 25mm and 1 in 125 verticality Installed through cemented layers Auger worked Good programme Clutches - good water tightness Boring piles used for Crossrail durability Could have been steel?

22 Conclusions Long History of Steel Piling at Canary Wharf:- Phase 1 Steel Deck Piles (1980 s). Phase 2 to 4 S Pile Cofferdams - Hammers (1990 s). Blackwell Pl. BP1 S Pile Cofferdam Vibrators (2002). Blackwell Pl. BP3/4 S Pile cantilever Vibrators (2005). Riverside Giken Crush S Piles - next to JLE (2008). Crossrail Giken Tubes (2010). Noise and Vibration - now very important:- Wood Wharf Cantilever - Vibration / boring. Bank Street Cofferdam - Giken.

23 Conclusions Long History of Steel Piling at Canary Wharf:- Phase 1 Steel Deck Piles (1980 s). Phase 2 to 4 S Pile Cofferdams - Hammers (1990 s). Blackwell Pl. BP1 S Pile Cofferdam Vibrators (2002). Blackwell Pl. BP3/4 S Pile cantilever Vibrators (2005). Riverside Giken Crush S Piles - next to JLE (2008). Crossrail Giken Tubes (2010). Noise and Vibration - now very important:- Wood Wharf Cantilever - Vibration / boring. Bank Street Cofferdam - Giken.

24 Combi-wall within temporary casing Permanent works - ARUP Alternative Combi-wall Desing ByrneLooby Combi-wall Contractor Commercal Marine & Piling Ltd Concrete core piles - BBGE

25 Combi-wall with temporary casing Spec required push system for adjacent buildings. Dewater to 8m. Calculated Defl. = 0.45m Casings 1.219m dia, 13 to 19mm thick with connectors 1400mm Sheet piles Z Hoesch H1807

26 Temporary casings Piling gate for temp. casings. Excavate through temp. casing (Hard Calcrete layer) Install permanent casing and fill gap with gravel. Gap allows for tolerance.

27 Sheetpiles and Permanent Piles Alternative piles extended with permanent RC piles Dewatering. Waling beams added.

28 Conclusions Permanent works - ARUP Alternative Combi-wall Desing ByrneLooby Combi-wall Contractor Commercal Marine & Piling Ltd Concrete core piles - BBGE

29 Thank you for your attention Any Questions

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