Gabion Applications
Gabions can be used in a wide variety of ways, from earth retention, to building materials and cladding.
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NavGabions can be used in a wide variety of ways, from earth retention, to building materials and cladding.
Gabion walls are flexible structures where the design is based on the mass of the gabions providing stability against the disturbing forces due to the soil and surcharges.
HY-TEN offer a design service to assist engineers and architects in design preparation.
In general gabion walls are inclined at 6 degrees from the vertical to improve stability, with the correct gabion specification the inclination can be increased normally to a maximum of 10 degrees which can provide cost savings in design. Care should be taken in designing vertical walls because of their flexible nature.
Gabion walls can either be designed with a stepped or flush face to suit requirements. Planting on the steps can be achieved to green up gabion structures. Flush faced walls can be clad with timber if the aesthetics of a stone face are not in keeping with the environment.
Mass Gravity Retaining Wall - Royal Tunbridge Wells, Kent
Mass Gravity Retaining Wall - Bangor University, Gwynedd
Mass Gravity Retaining Wall - Kangasala, Finland
This application of gabions is relatively new, the purpose is to achieve a textured finish to buildings and other structures.
Normally a thin vertical face of gabions 0.3 to 0.5m thick is secured to the main body of the building with clamp bars. Sizing of the cells of the units is important for constructional and aesthetic reasons and should not exceed a face area of 0.7 x 0.7m, otherwise deformation of the face can occur. The minimum wire diameter for the gabions should be 4mm for cladding up to 4 to 5m. Above this height a 5mm diameter should be used for the lower 4 to 5 m with a 4mm wire above.
Gabion Cladding - Daventry, Northamptonshire
Where a gabion facing is required with a sloping face, trapezoidal gabions can be used with the face inclined and the rear face vertical. It may be possible to design this type of cladding as an effectively free standing wall not physically tied back to the main structure.
Gateshead
Bristol parkway
NS & I Blackpool
The Rock, Bury
Free standing perimeter wallings or sound wallings formed of gabions are preferably trapezoidal in section (see Trapezoidal Gabions), the mass providing stability against wind loading and pedestrian barrier loading.
As these types of structures are normally highly visible and quality of construction is paramount, a heavy wire normally 4.0 or 5.0mm should be specified. It is recommended that the maximum unit height is 0.7m and that units are sub divided into cell lengths of maximum 0.7m.
Free Standing Walls - Gerrards Cross, Buckinghamshire
The Rock, Bury
Malvik Senter, Sweeden
Dead Man's Corner, Whitstable Harbour
Community Hub, South Marsh
Gabion units are traditionally rectangular in section, however for some applications it is preferable to have units which are trapezoidal in shape with either one or two faces inclined. Typical structures are freestanding perimeter or boundary walls which for aesthetic reasons are more acceptable than traditional rectangular section walls.
The degree of inclinations that can be achieved is related to the mesh size, ideally inclinations of one or two meshes in the height of the unit. It is preferable to limit the height to 700mm (9 meshes) for quality of installation. As a result the system follows closely the HY-TEN Gabion 700 system, but with inclined faces.
Trapezoidal Gabion Units - Daventry, Northamptonshire
To form trapezoidal units the diaphragm and end panels are of dimensions equal to the top width of the unit. To secure the face and rear panels at the set inclination, additional link panels are supplied loose, which are fixed on site to the inclined panels at the diaphragm locations. This is so that they overlap the main diaphragm panel at the correct inclination. These flap type panels are then wired to the main diaphragms.
At the extremities of the wall the corners are edged with 76.2mm x 12.7mm mesh to provide a full closure of the end panels and a clean joint at the corners.
Defford
Trapezoidal Gabions
Gabion Baskets may also be used to add interest and character to a project through bespoke architectural features; such as timber-seated benches, water features, sculptural installations & unique planting solutions.
Please feel free to contact us to discuss these possibilities on an individual basis.
Bespoke Gabion Structure - Castleford, West Yorkshire
Bespoke Gabion Structure - Gerrards Cross, Buckinghamshire
Bespoke Gabion Structure - Gateshead, Tyne and Wear
Gabion fencing is the construction of thin section walls, normally 0.3 to 0.5m wide with vertical faces. The gabions cannot provide stability on their own, they require additional support to resist wind loading in the form of steel posts.
The design can consider the stability provided by the mass of the wall with the post providing the resistance to the resultant moment required to provide adequate factors of safety. Loadings due to wind and pedestrian barriers must be considered in design.
The minimum wire diameter for the units should be 4mm and the cell face area should not exceed 0.7m x 0.7m, otherwise deformation of the face can occur.
Gabion Fencing - Wishaw, North Lanarkshire
Gabion faced reinforced soil walls are a system where the structural stability is achieved by virtue of reinforcement layers of polymer geogrids or steel mesh being placed in the soil linked to a facing skin of gabions.
This type of structure is generally more cost effective for walls 3 to 4m or more in height in fill situations.
As with mass gravity walls the gabion face is inclined at 6 degrees to the vertical and/or stepped.
Design is based on British Standard BS8002 with the gabion face being considered as part of the reinforced soil mass.
A combination of Free Standing & Mass Gravity Retaining Walls - Bjorkrkarr, Sweden
Gabion revetments are constructed to stabilise surface slips on embankments or as a method to prevent rock falls on escarpments, they do not normally provide stability to the slope against deep slip failures or for normal retaining stability.
Where retaining structures require a steepened berm (i.e. the internal angle of friction of the retained soil is less than the slope angle above the gabion walling), a steepened revetment can be provided. However, the active soil thrusts must be computed for the overall height in determining the gabion wall section.
Soils must be adequately compacted behind each course as part of each gabion bears onto the soil backfill, if this is not carried out settlement of the structure will occur.
Gabion Revetment - Eiterfjord, Norway
Gabion river walling is designed as a mass gravity structure, however if the river water levels are variable then the wall should be designed on the basis that the soil is saturated and the possibility of residual hydrostatic pressures as a result of rapid draw down must be considered.
The wall foundation must be protected against under scour by either of the means detailed below. For scour aprons the width of mattress protection in front of the wall should be 1.5 to 2 times the anticipated depth of scour and for embedment solutions the depth should be greater than the anticipated scour depth.
If adequate scour protection is not given failure by rotatation or settlement of the wall will occur.
River Walling - Ambleside, Cumbria
Coastal protection using gabions should be limited to a secondary defence in exposed areas or a primary defence in sheltered or estuary locations.
The protection system can be as a retaining structure or as a revetment. In all cases, only PVC-zinc coated or stainless steel gabions should be considered, as zinc or aluminium-zinc coatings are susceptible to corrosion (however if the structures are temporary then these coatings can be considered).
Due to the imposed forces created by breaking waves revetment slopes should not exceed 1 in 3 and quality of construction is very important. Units must be packed tightly otherwise stone movement within the basket will occur resulting in abrasion of the fabric of the gabion.
Adequate consideration must be made to toe scour, whether it be a retaining structure or a sloping revetment, otherwise failure due to undermining will occur.
Advice should always be sought for each situation.
Eterfjord, Norway
These types of structures generally combine a retaining wall with wing walls and a scour protection apron often form part of a river wall protection scheme where drainage pipes discharge into water courses.
The gabions may also be used only as scour apron protection to concrete outfall or inlet structures to provide erosion protection.
Due to the nature of discharge of the outfalls, consideration of the turbulent flow conditions occurring is required when determining the depth of gabion protection.
The design considerations are similar to those encountered in culverts and around bridge piers.
Weir structures are used where there is a sudden change in river bed levels or on steep gradients in water courses to reduce water velocity. The weir is effectively a dam which allows water to flow over the crest controlled by introducing a notch that can be rectangular or ‘V’ shaped.
The water can flow over the notch to a lower bed level, the weir is designed as a retaining structure with an apron protection to prevent erosion of the bed. In instances where there are high flows over the weir, it may require a stilling pool to be included in the design generally with an additional counter weir. These structures require the hydraulic conditions within the water course to be considered to determine the protection of the river bed on the down stream side. The flow conditions are turbulent and the mattress protection depth will be greater than for normal gabion mattress protection works.
Where a large change in bed level is required over a short distance a series of concurrent drops can be created known as a cascade structure.
In some instances a sloping weir may be necessary which results in increased water velocity. The slope is protected with a mattress or gabion system. Consideration is required for the erosive nature of high water velocities and the down stream river bank and bed protection.
Weir Structure - Betchworth, Surrey
For enquiries relating to Gabions, please contact our Wolverhampton Office.
Unit A, Dunstall Hill Trading Estate, Wolverhampton, West Midlands, WV6 0PJ