SteelWall & Mill-Pro Heavy & Ultra Heavy duty clutches for pile to pile and pile to sheet pile connections April 3, 2014
Clutch History Traditional Larssen Clutch bars have been around as long as Larssen sheet piles The C9 Clutch bar is a well known proprietary product of Arcelor but there are also equivalent products such as the SteelWall L8 a 1000Kn/m rated clutch. SteelWall is a German Clutch bar specialist (Est. 1989). In 2006 SteelWall developed the 12mm LPB family of Heavy Clutches. Rated 50% higher than traditional C9 or L8 bars, the LPB fully integrates with AZ, Z & U section sheet piles and exceeds 1500Kn/m max tensile load. Installed base is ~100,000 linear meters and will exceed 250,000m by end of 2014 Pipe-Pipe-Combi wall creation with a single product
Comparing Clutches Rated Tensile Strength Comparison Clutch bars - Kn/m 3500 3000 Max Tensile Load Kn/m 2500 2000 1500 1000 500 0 600 1000 1500 8mm Cold Rolled Clutch L8 (C9) Hot Rolled Clutch LPB 100/180-12 LPB 100/180-16 FD 180-12 Three Point Clutch 2000 3400 Standard Clutches Heavy Clutch Ultra Heavy Clutches Standard, Heavy & Ultra Heavy duty clutches
Traverse Shear Transfer in Clutched Pipe Walls Clutch to pipe with full penetration welds and fully coated
Gorodets Project at River Wolga, Russia 1500Kn/m rated LPB180 clutch bars Rock & Silt Geotech
Combi Walls LPB100/180 While hot rolled and extruded clutch bars are inherently strong, the SteelWall design also allows up to 25% roatation about the clutch axis affording the flexibility essential during driving allignment. The LPB 12mm sections are completely interconnectable with Larssen type Z & U sheet piles. Pile to Pile with 100, 180, 268mm spacing Pile to Larssen Z sheet Pile, (AZ, Arcelor, Hoesch) Pile to Larssen U Sheet piles LPB s Connect to themselves + AZ, Z & U Larssen sheets
LPB100-16, LPB180-16, LPB247 ~ 16mm 0.62 Variants include the LPB100, allowing closer pile to pile centres and the LPB247 to match Japanese fabricated Clutch spacings. The LPB100/180-16 is a thicker section providing increased tensile load of >2000Kn/m (not interconnectable with sheet). Manufactured from Grade S355 steel (Min YP 350Mpa), the LPB100/180 is welded using full penetration welds. As with sheet pile, binding clutches allow the transfer of traverse shear stress between piles up to the clutch rating. All LPB series clutches are strong enough to correct pile twist during driving, acting as a guide for the adjacent pile being driven and are suitable for driving directly into rock - including substrate granite. Clutches can be coated to the same standard as the pile up to the interface which can be sealed with clutch sealant to provide a wateright joint. SteelWall connectors comply to EuroCode 10248 &10249
1500 & 2000Kn/m Rated Clutch Bars Independent testing The LPB100/180 a 12mm section rated for 1500Kn/m in tensile and travserse shear stress The LPB180-16 rated for 2000Kn/m maximum tensile strength with full penetration welds Larssen type connection interconnectable with AZ, Z & U Sheet Piles (Arcelor, Hoesch, TK) Can be fully coated externally and driven with pre applied sealant for a fully watertight joint Fully coated watertight high load clutch joints
FD180 3 Point Ball & Socket Clutches The FD180 is a Grade S355 12mm section ball & socket type joint. The three points of connection provide a huge increase in tensile load transfer - up to 3400Kn per m of clutch. FD180 It is not compitable with Larssen sections, however it is ideal for pile to pile clutching where geotech forces the piles to share loads across them The 12mm section minimises heat input during welding whilst increasing load bearing capability The FD180 must be installed in the correct orientation Ultimate tensile & shear capacity
3400Kn/m Rated Clutch Bar Independent testing The FD180 is rated for 3400Kn/m maximum tensile strength with full penetration welds Three point connection using a 12mm section in Grade 355Mpa provides incredible tensile strength and shear force transfer for pile to pile connections Can be fully coated externally and driven with pre applied sealant for a fully watertight joint 20m of clutch provides 68,000Kn of tensile strength
Clutched Pile Coating System Mill-Pro has developed an exceptional coating methodology for clutched piles. Utalising the Lonkey process, we apply & cure up to 4000m2/day of Ultra High build epoxy 1500um thick, to AS/NZS 3750.2, then apply clutches and post coat the clutch area (~10% of the surface). Using the same 100% solids epoxy, clutches are fully cured in 3-5 hours This allows the pipes to be coated and handled immediatly eliminating coating damage 1500um ultra high build epoxy fully cured in 15 minutes
Clutched Pile Coating System The Longkey process applies FOUR 75% overlapping wet on wet coats of 100% solids UHB epoxy to a maximum DFT of 1500um. Hot applied to a hot substrate - Post heated to fully cure in 15 minutes. The result is ~ 40% increase in the typical mechanical propoerties of high build epoxies: (Adhesion, Cathodic disbondment, hardness, abrasion resistance, impact strength) Application is highly accurate with the nominated DFT controlled within +/-7% 1500um ultra high build epoxy fully cured in 15 minutes
Clutched Pile Coating System CROSS SECTION WITH CLUTCH AREA PRIMED Pipes are coated using the Longkey process Blasted Strip is primed after masking removed to protect blasted area before clutch welding. In a separate operation clutches blasted externally to AS1627.4 SA2.5 50um and primed with Sigma weld 165 CLUTCH FITTED & WELDED Pipes are is held in a Jig, Clutches are tacked in place to ensure alignment, Existing coating is protected using covers built into the Jigs and on the pipes themselves The Clutch is welded with full penetration fillet welds on each side. Pile is rotated and action is repeated on the other side of the pile CLUTCHED PILE PREPARED NDE of the weld, area mechanically abraded to SSPC- SP11 or pencil blasted to AS1627.4 Existing epoxy edges are feathered as a key for the manual clutch coating to The Inside of the clutch has a stripe coat of Sigma Shield 880 applied by brush to prevent bleeding during shipping and storage, Clutches cannot be not fully coated inside COATING REINSTATED Clutches and primed area coated with the required DFT of 880XS hot applied Cold cured 100% solids epoxy Operation by hand in a temperature controlled environment Coating is final inspected & holiday tested Piles are protected with dunnage for transport & slung for load out Piles & clutches are fully coated & protected
Clutched Pile Coating System The result is a fully coated clutched pile ready to drive 1500um ultra high build epoxy fully cured in 15 minutes
Fabricated clutch connectors L sections are tack welded on one side into place, a partial or full penetration weld is applied from the outside. A corrosponding Internal backing weld is not possible due to size constriant L section fold out when load is applied is the typical failure mode, limiting shear transfer Post grouting of the L&T to prevent water inflows is typically highly unsucessful Full penetration welds and coating are simply not possible on the inside of L sections L sections tend to fold out when load is applied No weld or coating inside the clutch, tidal through flow
Fabricated clutch connectors Typical T created using 2 x 8mm G250Mpa flat bars Typically in L&T clutching the desired size or grade sections are not available, so they are fabricated from flat bar creating up to 12 welds per joint Not ideal for immersed sea walls where coating is not possible and tidal flow constantly brings freshly oxygnated water into the clutch. Rolled L&T sections are typically not available in size or grade
Pile Ovality Ovality can increase from 0.5% upto 3% due to full penetration clutch welding. Excessive ovality can cause major pile allignment problems during pile driving and in the driving gates. DSAW Helically formed (Spiral) pipe has typical ovality of ~0.5% of Diameter. Ovality resulting from heat input is a function of length of weld, weld size & type, pile diameter, pipe thickness (D/t ratio) Ovality increases through the axis the clutches are fitted, causing pile driving alignment issues On L8 (C9) type clutches, full penetration welds are not possible due to the radii involved. Staggered alternate fillet welds in 500mm long runs from oposing ends helps to reduce heat input. LPB & FD clutch bars can be welded using full penetration welds but L&T s cannot. Minimise heat input to avoid ovality issues