SUPPORT ARCHES

Support arches

Metal support arches are used in a wide range of applications and with many different soil conditions, offering the advantage of being resistance to compression and traction efforts with a high bending moment. This support technique is suitable for soil conditions that are very prone to subsidence due to the efforts caused by converging soils.

Cold curved beams are used to adapt to the excavation diameter, using the radii required to install them in parallel to the soil. Our entire manufacturing process, from design, bending, welding and dispatch, is certified by:

EN-1090 (CE marking) yand governed according to the ISO9001 quality system.

Rigid “HEB” support arches

High-resistance beams that maintain the cross-section dimensions with a low deformation or in which the decompressed soil thickness around the tunnel must be limited within strict parameters. The sectors are joined to form the entire arch using bolted joints between the plates.

Characteristics of HEB beams

TYPE OF BEAM DIMENSIONS CROSS-SECTION WEIGHT (kg/m)
h b e e1(mm) Ix (cm4) Wx (cm3) Iy(cm4) Wy (cm3)
HEB 100 100 100 6 10 450 90 167 33 20,4
HEB 120 120 120 6,5 11 864 144 318 53 26,7
HEB 140 140 140 7 12 1509 216 550 79 33,7
HEB 160 160 160 8 13 2492 311 889 111 42,6
HEB 180 180 180 8,5 15 3831 426 1363 151 51,2
CHARACTERISTICS OF HEB BEAMS
STEEL QUALITY S275JR EN10025 >275 N/mm2
STEEL QUALITY S355JR EN10025 >355 N/mm2

The beams in the table show the most common dimensions used for support elements, although these can be manufactured up to HEB280. The dimensions and bend radius are usually indicated under the customer’s needs and requirements, although our highly-qualified technical office has a vast experience in designing and manufacturing the optimum beam in terms of resistance and weight/metre ratio.

THN Sliding support arches

Support arches manufactured with a THN omega beam. The THN beam has a high transversal inertia momentum in terms of weight per metre. The sectors are placed one on top of the other (overlapping) and they remain joined by two flanges or clamps. These frames are subject to deformation, caused by their assembly. The slipping resistance depends on how tight the clamps are. This type of arches combine the high resistance of metal support elements with the sliding properties of the arch, which give way when the soil pressure reaches a certain value, preventing failure in the arch. Another of the main benefits is its simple and quick installation, as well as adapting better to the excavated section.

These can be curved inversely, upon special order, a system that is commonly used in tunnels executed in civil works projects.

Standard cross-sections are used, but the radii and sectors are usually specified by the customer. Our highly-qualified technical office has a vast experience in designing and manufacturing the optimum beam in terms of resistance and weight/metre ratio.

Characteristics of TNH beams

TYPE OF BEAM DIMENSIONS CROSS-SECTION WEIGHT (kg/m)
h b e e1(mm) Ix (cm4) Wx (cm3) Iy(cm4) Wy (cm3)
THN 16,5 106 90 44,25 13 173 38 227 43 16,7
THN 21 127 108 54 12 324 60 410 64 21
THN 29 150,5 124 58,2 16 616 94 775 103 29
THN 36 171 138 66,8 17 969 136 265 149 36
CHARACTERISTICS OF SUPPORT ARCHES WITH THN BEAMS
STEEL QUALITY 31Mn4 EN21544 >350 N/mm2
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