Steel Ribs Sample Clauses
Steel Ribs. Steel ribs provide an immediate support of the excavation after installation and shall subsequently act as reinforcement and load distributing members for the shotcrete lining. Steel ribs are required as support for forepoling elements, which are installed in advance of the excavation. During the entire construction period, they will contribute as load bearing members within the shotcrete lining. The steel ribs shall be manufactured to meet the geometrical requirements for the excavation geometries for each Excavation Class including the relevant tolerances. Prior to the beginning of the work the complete fabrication details, installation procedures and layout, details of joints, rib connections, rib spacers, geometry etc. and certificates of compliance of the materials shall be submitted to the Employer’s Representative for approval. The fabrication and installation of structural steel support shall conform to the latest edition of the following Indian Standards or, where not covered by these Standards, to the equivalent International Standards: - IS: 800 Code of practice for general construction in steel - IS: 808 Dimensions for Hot Rolled Steel Beam, Column, Channel and Angle Sections - IS: 816 Code of practice for use of metal arc welding for general construction in mild steel - IS: 2062 Steel for general structural purposes Rib splices shall be welded or connected with bolted plates. Splices shall not reduce the section moment of resistance. Where possible all connections shall be welded, and all field connections shall be bolted. Arches, base plates, ties and connections shall be formed from steel with the characteristic in accordance to reinforced concrete standards. Arches shall be rolled to suit the dimensional requirements of the Contract. Welding shall conform with BS EN 1011-1. Holes for ties, struts and any bolted connections shall be drilled. No burning will be allowed whether for temporary Works items or permanent elements. Threaded tie rods and struts shall be of adequate length to suit arch centres and allow 25 mm projection each end beyond the nut. Where arches are to be provided as part of the Contractor’s obligation for support the Contractor shall provide dimensional details of the arches, calculations regarding imposed loads and design and such other information that the Employer’s Representative may reasonably request. Galvanized arches, where required, shall be treated in accordance with BS EN ISO 1461. All components, including the...