Posted to News on 29th Sep 2007, 19:34
No-drill clamps are simple, reliable and reusable
Lindapter has supplied M20-bolted Lindapter clamps for use in temporary girder-based supporting structures that are required for constructing concrete piers.
Lindapter steelwork clamps are simplifying the construction of the on/off ramps needed for the Brisbane North South Bypass Tunnel project. When completed, this 6.8km long construction will be the longest tunnel in Australia.
The piers that support the ramps are being made by the formwork and scaffolding specialist PERI Australia, and consist of a headstock supported by two columns. The headstocks are fabricated in situ by pouring concrete into pre-assembled formwork, which is positioned on top of the columns with the aid of some simple supporting steelwork.
Bolt-on Lindapter clamps were selected as the means of assembling this girder-based supporting structure because they attach without the need to drill holes. The clamps may be moved easily, and this flexibility is critical because the pier length and column spacings vary throughout the course of the ramps. As soon as the concrete gains enough strength, the formwork and support steelwork are stripped away, and adjusted to the dimensions needed to fabricate the following pier.
Cost-effective tooling
Fred Dagandan, Design Engineer with PERI Australia Pty Limited, comments: "Lindapter clamps have helped us create very cost-effective tooling for fabricating the piers required on this major project. Their ease of assembly, disassembly and adjustment, combined with special flexibility we have built into our formworks, means that we can quickly recycle. On this project, a total of some 60 piers are being constructed using just two sets of formworks."
M20-bolted Lindapter clamps were used to support the large loads required during construction. During the fabrication of a pier, the total vertical load of the support steelwork, formwork, steel reinforcement, and fresh concrete is approximately 100 tonnes.
A combination of conventional and high-friction Lindapter clamps are used to assemble the steelwork. The M20 high-friction clamps support safe working frictional loads of 16kN per pair of bolts, and tensile loads of 26.25kN per bolt. During the course of this project, each Lindapter clamp will be reused approximately 30 times.
