4/25/2023 0 Comments North strathfield rail underpassA new array of canopy tubes and pattern of face dowels were installed every 9m length of tunnel with a minimum of 3m overlap. The construction method used 12m long grouted steel canopy tubes and approximately 35no., 12m fiberglass dowels across the face followed by incremental excavation, which were carried out in 1.3m to 1.5m lengths with shotcrete built up in multiple layers immediately behind the tunnel face.The tunnel excavation was completed with no distribution to the railway operations above. Although macro fibers were not specifically used for fire and are not as effective as micro fibers for this purpose, the underlying macro synthetic fibers in the structural shotcrete layer will also help to reduce spalling in the event of a fire. The final shotcrete layer is 100mm in thickness using micro synthetic fibers to reduce spalling in the event of a fire.Are environmentally friendly and will not deteriorate over the 100-year life of the tunnel.To provide residual strength and redistribute stresses within the lining.To minimise shrinkage cracking within the shotcrete lining.Barchip’s macro synthetic fibers in the initial structural shotcrete lining have four functions The design is based on an arched profile ensuring that the fiber reinforced shotcrete itself is always in compression under both dead and live loading. No steel sets or lattice girders were used on this project. Steel canopy tubes drilled ahead of the tunnel face provide the initial ground support ahead following the shotcrete lining. The permanent ground support in the tunnel consists of a 250mm thick Barchip macro synthetic fiber reinforced single pass (wet mix) sprayed shotcrete lining. The tunnel has a maximum ground cover of 3m, consisting of track ballast overlying fill and shale rock which is weathered near the surface. The lead designers were the DJV of SKM and PB with Mott Macdonald the designer of the driven tunnel discussed here. The project was delivered by the NSRU Alliance (TfNSW, John Holland and Bouygues). The 9m wide, arched roof single tunnel was excavated by a road header underneath operational passenger and freight railway lines with a maximum cover of 3m. While short, the tunnel required and includes numerous technical innovations and takes full advantage of the benefits offered from Barchip’s fiber reinforced shotcrete. The North Strathfield Rail Underpass tunnel in Sydney, Australia, is a 148m long rail tunnel designed for freight trains up to 1.5km in length.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |