H1000 Stay Cable System

Transcription

1 H1000 Stay Cable System

2 H1000 Stay Cable System Freyssinet has developed the new H1000 stay cable for use in lighter structures. It is a smaller cable designed to complement and extend the high capacity HD range of stay cables. Applications include stay cables or hangers for pedestrian walkways, bowstring arch bridges, suspended roofs and other cabled structures. A cost effective and durable system The H1000 stay cable is a parallel strand system cable made up from a group of individually anchored strands. The H1000 cables are light and can be prefabricated. The simplified anchorage design and the prefabrication of the cables enable an easy installation on the structure and make the H1000 system highly competitive while retaining the fatigue resistance and corrosion protection performance of the Freyssinet HD stay cable. H1000 Technology The H1000 system is based on each strand being fully independent and has the following features: Each strand is individually anchored by jaws or swages, Each strand is individually protected against corrosion, The strand group is generally protected by a coloured polyethylene outer sheath, Strands can be removed and replaced if necessary. The H1000 compact cable sheath provides for a slender cable to meet the expectations of architects for light structures throughout the world. Freyssinet Monostrand The main tensile element consists of a bundle of individually protected parallel seven-wire T15.7 strands. This patented strand, the Freyssinet Monostrand, has outstanding durability both mechanically and against ageing. The strand has a double corrosion protection barrier formed by hot dip galvanisation of the individual wires of the strand before the final drawing and a polyethylene sheath extruded around the strand. The interstices between the wires and the sheath are filled with petroleum wax.

3 Freyssinet H1000 Anchorage The H1000 range includes four cable sizes for 4, 7, 12 and 19 strands. Several H1000 anchorage configurations are available to cover the needs of the connection to the structure. A special fatigue swage Passive anchorages use swages specially designed for a high fatigue resistance. This anchorage complies with both the Interministerial Prestressing Commission (CIP) and the Post Tensioning Institute (PTI) recommendations for stay cables providing two million stress cycles with a 200 MPa axial stress range, a 45% GUTS maximum stress and 10 mrad angular deviation. Thus, the H1000 system has the same fatigue performance as the HD system. Various options The H1000 system is fitted with an adjustable lower anchorage and fixed upper anchorage. At both ends, a fork anchorage or a cylindrical anchorage can be used. Lower anchorages can be prefabricated using swages with tensioning applied to the whole cable or partially prefabricated using jaws for monostrand tensioning (Isotension method) Where jaws are used the anchorage is sealed with the patented Freyssinet stuffing box. With swages, individual sealing devices are installed on each strand. Cable force adjustment is provided for with a threaded anchorage and a nut. Lower partially prefabricated anchorage Upper fixed anchorage Stuffing box Anchorage block Nut Anchorage cap Anchorage block Jaws Strand Bearing plate Flange Swage 3

4 Upper anchorage Upper fork anchorage The strands in this anchorage are anchored by swages in a block screwed to a fork fixing. The latter, made of machined steel, is hinged to the structure with a pin. Fork dia. L min.* Pin Upper fixed anchorage The strands are anchored with swages in a block resting on a bearing plate with half shims. Half shims L min.* Dimensions (mm) Unit L Formwork tube Upper Lower Dia. Th. Dia. Th. Th. Bearing plate Block Injection cap Duct Upper Lower Upper Lower Upper Lower Side Hole dia. Side Hole dia. Dia. Th. Th. Th. Dia. Leng. Dia. Leng. Dia. Fork Pin (Dia. = Diameter ; Th. = Thickness ; Leng. = Length ; L min. = Minimum Length) * L min. = x L stay + L («L» is the length of tube needed for the angular deviation of the strands at the anchorage exit and «0.016» corresponds to the thermal movement of the stay pipe). 4

5 Lower anchorage Lower fork anchorage The cable is fully prefabricated with both anchorages. The strands are anchored with swages in a block screwed to a fork creating an articulated connection. This machined steel fork has a turnbuckle for adjustment and tensioning. Lower prefabricated anchorage The cable is fully prefabricated with both anchorages. The strands are anchored with swages in a block. This block is threaded to allow the cable tensioning and adjustment with a nut and an annular jack. Adjustment with nut (necessary for tensioning) Lower partially prefabricated anchorage The cable is partially prefabricated with the upper anchorage only. The strands are anchored at the deck with conical jaws in an anchorage fitted with a stuffing box. The cable is tensioned strand by strand using the Isotension system. The anchorage bears on the structure by means of a nut for further cable adjustment. Adjustment with nut 5

6 Outer pipe An outer high density polyethylene pipe protects the bundle of strands improving the cable aesthetics. The pipe is bi-extruded with an outer coloured layer and is specially formulated for a high durability in sunlight. A wide range of colours is available (non-contractual colour chart, non-exhaustive list) white light grey pastel blue mediterranean yellow red green metallic grey black blue Installation Prefabrication (in factory or on site) cutting strands to length, welding outer sheaths swage threading on strands in the upper anchorage, and possibly the lower one, fork installation. Erection hoisting and attaching the upper anchorage to the structure, inserting the cable or the lower anchorage in the structure, tensioning. Isotension - jack dimensions 275 mm 265 mm 1085 mm 2000 mm* L 100 mm Cable force adjustment Dimensions (mm) Unit A L A mm *This length is necessary to use the jack, it can be accommodated if requested. 6

7 Some references Astana Bow string (Kazakhstan) Completion: 2006 Total length: 150 m Type of anchorages: 12T15 Upper fixed anchorage / Lower partly prefabricated anchorage Kanne Bridge (Belgium) Completion: 2005 Total length: m Main span length: m Type of anchorages: 7T15 Upper fork anchorage / Lower prefabricated anchorage Illarsaz Footbridge (Switzerland) Completion: 2005 Total length: m Type of anchorages: 4T15 Upper fixed anchorage / Lower partly prefabricated anchorage Sarvar Bridge (Hungary) Completion: 2004 Total length: m Type of anchorages: 7T15 Upper fixed anchorage / Lower partly prefabricated anchorage Cairo Airport Footbridge (Egypt) Completion: 2004 Total length: 86 m Type of anchorages: 7T15 Upper fixed anchorage / Lower partly prefabricated anchorage Doomul Footbridge (South Korea) Completion: 2004 Total length: m Type of anchorages: 7T15 Upper fork anchorage / Lower fork anchorage 7

8 1 bis, rue du Petit Clamart Vélizy-Villacoublay - France Tel.: Fax: Photos: D. R. - FREYSSINET / September 2006.