RETAINING WALL SYSTEM ViaWall ViaWall A ViaWall B ViaBlock
Table of contents Introduction page 1 ViaWall type A Elements of the system 1. Reinforced concrete panel 2. Reinforcing meshes 3. U-bolts Additional elements Backfill Advantages of using the ViaWall A system ViaWall A: cross-section page 3 page 3 page 4 page 4 page 5 page 6 page 6 page 7 ViaWall type B Elements of the system 1. Meshes 2. Backfill Advantages of using the ViaWall B system ViaWall B: cross-section page 8 page 8 page 9 page 9 page 10 ViaBlock Elements of the system 1. Blocks 2. Geosynthetic Additional elements Advantages of using the ViaWall B system ViaBlock: cross-section Installation of retaining walls About us page 11 page 11 page 12 page 13 page 13 page 14 page 15 page 17
Introduction Retaining structures ViaCon Poland Sp. z o.o. is a manufacturer of three Mechanically Stabilized Earth (MSE) systems: ViaWall A ViaWall B ViaBlock a retaining wall with the face from a reinforced concrete panel a retaining wall with the face from a steel mesh a retaining wall with the face from concrete blocks Operating principle of retaining structures The idea of MSE walls consists in interoperation between anchoring elements (steel or geosynthetic reinforcing meshes) and engineering backfill. The reaction to the pressure caused by constant and variable loads is a tensile force in the anchoring elements. Adequate selection of the anchorage length prevents displacement of the face. 1.
Structural elements of retaining wall systems System Retaining wall face Reinforcing mesh ViaWall A type 1 ViaWall A type 2 ViaWall B ViaBlock reinforced concrete panel C30/37 reinforced concrete panel C30/37 galvanized steel reinforcing mesh, stone 80/250 vibropressed concrete block 15x20x24cm galvanized steel reinforcing mesh uniaxial PEHD geogrid galvanized steel reinforcing mesh geosynthetic The systems offered by ViaCon Polska Sp. z o.o. are easy to install, economical and durable thanks to the use of appropriate materials. The anticipated service life of MSE structures, in accordance with the Polish Standards and the Regulation of the Minister of Transport and Maritime Economy on technical requirements to be met by road engineering structures and their location, is min. 100 years of use for the galvanized steel reinforcing mesh, taking into account the loss of steel due to corrosion. In the scope of retaining structures, ViaCon Polska Sp. z o.o. offers: design support, preparation of an engineering design for each implementation, installation or installation instructions on the construction site. 2.
ViaWall A The system has obtained Technical Approval of the Road and Bridge Research Institute, No 1. AT/2011-02-2611/1 ViaWall A is a retaining wall system, in which reinforced concrete panels form the facing part of the wall, while galvanised steel reinforcing mesh or uniaxial PEHD geogrid forms the reinforcing part in the embankment. Elements of the system 1. Reinforced concrete panel The panel is made of concrete (grade C30/37) reinforced with steel (class A-III or higher). The system consists of typical panels with the following dimensions: 150x150x15 cm (18 cm) and 150x78,5x15 cm (18 cm) (width x height x thickness). It is possible to form panels with non-standard dimensions. Non-standard panels can have any shape, however the maximum size of a panel cannot exceed 220x150x15 cm (18 cm) or 150x220x15 cm (18 cm). The standard texture of panels is smooth concrete. It is possible to make panels with any texture, for example: occasional patterns, imitations of stone, rustication, checkering, etc. Panel properties Concrete Absorbability Frost resistance C30/37 5% F150 www.viacon.pl 3.
2. Reinforcing meshes Reinforcing meshes are made of steel bars (class A-III or higher), ribbed or smooth, with diameters from 6 to 12 mm. Reinforcing meshes consist of longitudinal bars spaced 250 mm from each other and transverse bars with a variable spacing of 300 mm, 600 mm or 900 mm. Mesh is protected against corrosion by a zinc layer with a coating weight of min. 600 g/m 2. 3. U-bolts Inseparable elements of the system are U-bolts that fasten reinforcing mesh to panels. U-bolts are protected against corrosion by a zinc layer with a coating weight of min. 600 g/m 2. The length, spacing and diameter of bars in reinforcing mesh depend on the height of a wall, loads, type of backfill, and the soil conditions of foundation. 4.
Additional elements EPDM rubber bearing pads (Shore hardness of 60-65 acc. to PN ISO 868: 2005) are placed between rows of panels; the thickness of pads is approx. 20 mm filter cloth (non-woven geotextile): belts with a width of min. 305 mm are laid from the side of the backfill in such a way as to cover all panel joints; its function is to prevent fine particles from being washed out from the embankment material. alignment rods - galvanized steel rods threaded at one side, which align the panels of the upper layer in relation to the bottom layer and facilitate proper installation of panels. EPDM rubber bearing Alignment rods www.viacon.pl 5.
Backfill Non-cohesive soil with the following parameters is used as backfill: min. internal friction angle φ = 34, cohesion c = 0 kpa, bulk density γ = 20.0 kn/m3 coefficient of uniformity Cu 4 (according to PN-86/B-02480), coefficient of curvature 1 Cc 3 (according to PN-86/B-02480). Advantages of using the ViaWall A system possibility of forming any geometric shapes easy to install and impervious to weather conditions (dependent only on the possibilities of compacting the backfill) installed with the use of light equipment only (the heaviest element: up to 1500 kg) possibility of using panel faces with various architectural textures 6.
ViaWall A: cross-section Monolithic reinforced concrete cornice B35 EPS spacer (5 cm thick) non-cohesive soil backfill: Ismin=0.97 non-woven geotextile belts with a width of min. 305 mm mesh type 2 mesh type 3 Arrangement of non-woven geotextile fabric on panels from the side of backfill www.viacon.pl 7.
ViaWall B The system has obtained Technical Approval of the Road and Bridge Research Institute, No 2. AT/2011-02-2729/1 ViaWall B is a retaining wall system, in which steel reinforcing meshes form the face and reinforcement part of the embankment. Elements of the system 1. Meshes ViaWall B system includes two types of reinforcing meshes: main L-shaped mesh, which acts both as the face and the anchoring element, auxiliary mesh, which forms only the face of the wall; spacing between bars: 100x250 mm. Main and auxiliary meshes are made of welded steel bars (class A-III and higher) with bar diameters ranging from 6 to 12 mm. The length, spacing and diameter of the main mesh bars are variable and depend, among other things, on the height of the wall, loads, type of backfill and subsoil. In order to protect the mesh against corrosion, all elements of the system are covered with a zinc layer with a coating weight of min. 600 g/m 2. 8.
2. Backfill Backfill is an integral part of the system. Natural or crushed aggregate with a grain size of 80/250 is used in the facing part. In the remaining part, along the length of the mesh anchorage, there is used natural or crushed aggregate with a grain size of 0/80, coefficient of uniformity: Cu 4, and coefficient of curvature: 1 <Cc <3 (according to PN-86/B-02480), compacted to the degree of compaction Is 0.97 according to the standard Proctor test. A separating geotextile is used between the backfill in the facing part of the wall with a grain size of 80/250 and the backfill in the reinforcing part with a grain size of 0/80. Advantages of using the ViaWall B system quick and economical retaining wall system easy to install and impervious to weather conditions (dependent only on the possibilities of compacting the backfill) thanks to the use of natural stone in the facing part, the system perfectly integrates with the natural environment, e.g. in mountainous areas 9.
ViaWall B: cross-section Reinforced soil headwall Non-woven geotextile fabric - 500g/m 2 Detail A Soil reinforcement Detail B Aggregate foundation made of a gravel and sand mix compacted to the degree of compaction Is 0.98 (according to the standard Proctor test) Detail A Detail B Aggregate with a grain size of 80/250 Filter cloth (non-woven geotextile fabric) Aggregate with a grain size of 80/250 Face reinforcing mesh min. 0,20 cm Face reinforcing mesh Drainage pipe Ø160 mm Drain pipe Ø100 mm min. 0,60 cm min. 30 cm Subsoil reinforcement at the outlet of the drain pipe Soil reinforcement Geomembrane with the thickness of 1.0 mm Soil reinforcement 0,40 m 10.
ViaBlock The system has obtained Technical Approval of the Road and Bridge Research Institute, No 3. AT/2010-02-2666 ViaBlock is a retaining wall system, in which the face of the wall is made from ViaBlock concrete blocks combined with a geosynthetic reinforcing the embankment. Blocks constitute an integral part of the system and can be used with other elements of the system, e.g. uniaxial polyethylene geogrid and polyethylene connectors (T-clip). Elements of the system 1. Blocks There are two types of concrete blocks in the ViaBlock retaining wall system: wall blocks (active, passive), blocks crowning the wall. Wall blocks are available in two types - active and passive. At the top part of an active block, a connector connecting the geogrid with the block is placed and covered with a passive block. An active block is placed every few layers of passive blocks. The number of active block layers depends on the number of layers of the geogrids reinforcing the embankment. PASSIVE BLOCK The retaining wall can be finished at the top with a crowning precast element, a monolithic cover or a concrete rim. ACTIVE BLOCK Concrete Block properties Absorbability Frost resistance min. C25/C30 5% F150 ViaBlock - (vertical wall) ViaBlock - (slope wall - from 82 to 90 ) ViaBlock - (terrace wall - from 82 to 90 ) Fig.1 Examples of ViaBlock solutions View of the wall the side of backfill www.viacon.pl 11.
ViaBlock crowning element is fastened to a concrete crowning using anchors (rods with a diameter of 10 mm). Dimensions of the ViaBlock system cornice are presented in the figure below. 2.2. Geosynthetic An element that reinforces the embankment is TRENAX TT uniaxial polyethylene geogrid with rigid nodes. Properties of the TENAX TT RW uniaxial geogrid TENAX TT RW Mechanical properties Testing methods according to 045 060 090 120 160 Requirements Tensile strength EN ISO 10319 kn/m 57,0 73,0 109,0 145,0 165,0 Relative elongation at the maximum load EN ISO 10319 % 11,5 13,0 13,0 13,0 13,0 Tensile force at the relative elongation of 2% EN ISO 10319 kn/m 15,0 22,0 31,0 41,0 50,0 Tensile force at the relative elongation of 5% EN ISO 10319 kn/m 30,0 38,0 56,0 79,0 95,0 Node strength GRI -GG2 kn/m 37,0 51,0 81,0 111,0 131,0 12.
Additional elements polyethylene connector (T-Clip) for connecting blocks with the mesh; the connector has a specifically designed shape and therefore it should not be replaced with other elements bodkins (HDPE rods - 6x40x1050 mm) are used to transversely connect two geogrids. Advantages of using the ViaBlock system low cost of building a retaining wall quick and easy installation possibility of forming walls with various shapes (concave or convex arch) possibility of making blocks in different colours Currently available colours B1 B2 B3 B4 B5 www.viacon.pl 13.
ViaBlock: cross-section precast cornice acc. to the system solution 3 top blocks are connected using cement mortar connector passive block anchorage length L active block break boundary non-cohesive soil backfill φ = min. 340 Is =1.0 passive block active block connector aggregate 8/16 aggregate 16/31.5 PVC corrugated drainage pipe Ø150 mm Cement mortar CONCRETE FOUNDATION - 600 x 150 Drainage pipe Ø160 14.
Installation of retaining walls General rules for installation of MSE walls Installation of a retaining wall begins from preparation of the subsoil, which should achieve a load bearing capacity corresponding at least to the secondary modulus of elasticity: E2 min = 50 MPa. The next stage of installation for the ViaWall A and ViaBlock systems is construction of a levelling concrete footing (grade C20/25). The maximum deviation for the wall foundation level is ± 3 mm. ViaWall B system does not require the use of a levelling concrete footing. Aggregate foundation should be made under retaining walls of this type to level subsoil. Facing elements of the systems should be placed in whole layers along the entire length of the designed wall. ViaWall A panels should be placed with a gap of 2 cm, while ViaBlock blocks should be butted against each other. In ViaWall A and ViaBlock systems, the first layer of the facing elements should be placed on a levelling concrete footing. The size of footings for the ViaWall A system is 30x15 cm and for the ViaBlock system - 60x15 cm. In the ViaWall A system, the first layer of panels should be placed directly on the footing, secured against displacing or tipping, and then backfilled. Support and clamps, which position the facing parts of panels in relation to each other, are used for this purpose. www.viacon.pl 15.
ViaWall A panels should be placed horizontally and should be tilted vertically by 1% in the direction of the reinforcement (backfill). Backfilling should be carried out in layers every 30 cm, which should be compacted to a degree of compaction not higher than Is = 0.97 acc. to the standard Proctor test. In the facing part, at a distance of approx. 1 m from the face of the retaining wall, the backfill should be compacted using light compaction equipment, e.g. plate compactors. Outside this area, heavier compaction equipment can be used, e.g. rollers. Tamping rollers should not be used for compaction. Once the reinforcement is levelled, meshes should be laid and tensioned with the use of wooden wedges. Then, the backfilling and compacting operations should be continued. The above steps should be repeated until the designed height has been obtained. Levelling footing First layer of panels The first layer of panels from the side of the backfill Steel mesh fastening Steel meshes Alignment rods Non-woven geotextile belts from the side of the backfill Monolithic cornice crowning the wall 16.
ViaCon Sp. z o.o. ViaCon Sp. z o.o. is a member of ViaCon Group established in Sweden and Norway in 1986. At present ViaCon Group operates in a dozen or so European countries and belongs to SAFEROAD Group. Thanks to the support from the entire group and the possibility of using the shared experience, each member company can offer professional technical consulting and top quality products. Business profile of the company: steel pipes and flexible structures used for construction and repair of culverts, bridges, overpasses, tunnels, farm accommodation underpasses, wildlife crossings, other engineering structures, and used also as belt conveyor housings, manufacture, design and sale of storm water drainage systems and holding tanks, design, sale and installation of geosynthetics, such as non-woven geotextile fabrics, woven geotextile fabrics, geogrids, geomembranes, and bentonite mats, sale and lease of temporary bridges, sale of gabions, design, manufacture and sale of three retaining structure systems from reinforced soil.
PECOR OPTIMA HelCor HelCor PA MultiPlate MP200 SuperCor Acrow 700XS - temporary bridges Woven and non-woven geotextiles Geogrids Gabions HelCor TC holding tanks HelCor wells PECOR OPTIMA M wells ViaWall A retaining walls ViaWall B retaining walls Pecor Quattro sewage system ViaBlock retaining walls Our goal is to improve products and to cooperate closely with customers, scientific and research centres, public administration and suppliers. ViaCon Sp. z o.o. ul. Przemysłowa 6 64-130 Rydzyna, Poland phone: +48 65 525 45 45 fax: +48 65 525 45 55 e-mail: office@viacon.pl www.viacon.pl That s why our motto is: Let s Create a Better Future Together