Twin Cell Uniculvert - Holcim/Humes

Abstract

DESIGN OF THE TWIN CELL UNICULVERT The main priority was to ensure AURIZON could reduce the shutdown time of the rail line especially for the larger drainage crossings. 1.1 Construction Parameters- Main parameter is the speed of installation and constructability to ensure a reduction in rail shutdown time. Concrete supply can be a problematic in the Western Queensland areas of the AURIZON track assets. Concrete supply also requires a curing time which adds to the shutdown time. Overhead Power Lines are a consideration, this could restrict lifting capacity No insitu concrete footings or piling as required for a bridging structure 1.1.1 Outcomes- With speed of installation being the main parameter we determined; * that the larger the product the better, with bigger spans and reduced amount of lifting, * the product design would need different span widths and leg heights, * the Uniculvert, inclusive of the base slab instead of the standard culvert plus base slab construction, met with all the construction requirements. * In line with the reduction of onsite lifts and no overhead site restrictions the decision was made to increase the product to a twin cell configuration, * the product length was reviewed and Humes determined a product length of 2000mm was achievable. * Small insitu Stitch pours to tie the products together longitudinally and a post tension connection transversely were added to finalise the design, * Production Constraints- it was determined that the HUMES factories in both Rockhampton and Townsville did not provide any constraints to the production of the Twin Cell Uniculvert size and weights. * In addition, Precast Concrete Wingwalls and Precast Concrete Ballast Walls were incorporated into the design to further reduce the shutdown time. These elements eliminated completely the requirement for formwork/ placement of reinforcing, pouring and curing of insitu concrete within the rail corridor, * the initial 300LA product design for the first two (2) chainages was undertaken by AURIZON and supplied to HUMES for a review of the product constructability in our factories. * HUMES undertook the production of the mould for the Twin Cell Uniculvert with adjustable span widths from 1200 to 3600mm and adjustable leg heights from 1200 to 3600mm and a product length of 2000mm, 2 CONCLUSION The collaboration worked well with the experience from both teams producing the Twin Cell Uniculvert. We have so far installed 4 culvert structures on the rail network successfully. 3 REFERENCES • AURIZON Standard Culvert Drawings 300LA • CH NL22.100km Coolinsville Newlands Branch, drawings- AUR-Q-0470-0024