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In resolving problems associatedvvith river erosion or sea defencevvorks. Gabions are almost certainto be reqUired Gridvveld collapsibleGabions have been developed overthe years for this purpose, havebeen used on many vvefl-kriovvriprojects and offer a very economcalmethod of achieving the best.re:;~ts_
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Main uses are for:
RETAINING WALLSAPRONS, REVETMENTSCHANNEL LININGSWEIRS ANDDROP STRUCTURESCULVERT HEADWALLSOUTLET STRUCTURESBRIDGE ABUTMENTSWING WALLSLOW WATER BRIDGESFORDS, GROYNESRIVER DEFLECTORS
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GABIONS DO A TOUGH JOBRivers, sea coasts, roads and railvvays can all be subject to continuous orfluctuating erosion, demanding planned heavy defences vvhich are notmoveable by the vvater forces involved. Among methods by vvhich embank-ments and revetments can bemade, Gridyveld Gabions provide the cheapestpossible effective solution. They are sheets of vvelded vvire mesh made sethat they can be simply and quickly formed into boxes.Filled vvith boulders obtained locally, they are placed rovv upon rovv, intepositions vvhere they vvill offer maximum resistance to the vvater forcesoperating.For protection of areas subject to scour and erosion, carefully planneesiting of Gabions vvill not only arrest the natural activity, but also brineabout other beneficial effects such as directional silting. river trainingincreasing areas of habitable land. improved conditions for vvildlife and fis+and prevention of disrupted supply and sevverage lines.
WHY CHOOSE THE GRIDWELDTYPE OF GABION?* Gridvveld Gabions keep their basic shape because they are vvelded aevery intersection. Hovvever. they give enough yield for settlement aneearth movement.* Due to the flexibility of the interlocking block method of design. an'configuration and shape of area can be filled.* No additional filling or structure is needed because the Gabion qu; -I.,j,breathes and dissipates flood and vvave action. V* Increasing stability vvith time is provided by silting and grovvth 0vegetation.* No rod stretchers for alignment of mesh are necessary vvith all-vvelde(vvire mesh.
FACTORS OF ECONOMYThe lovv initial cost of Gridvveld Gabions is enhanced by the ability to us.local infill by unskilled labour. Belovv-surface excavations. special piling an.drainage facilities are unnecessary. No special machinery. tools or maintenance are needed and there is no vveitirvqfor setting. curing or any"tirneovvork.
ASSEMBLY AND SITINGGridvveld Collapsible Gabions are supplied flat as a series ot oariets linkeby vvelded rings at 6 spacings. Using unskilled labour. the flat Gabionare moved into position and the sides folded into a box shaped format vvrtan open lid. Adjoining faces are then secured vvith T clips or helical vvir(supplied vvith the Gabion) and it is then ready for filling after vvhich thlid is secured in a simlar fashion. In most cases it is advisable to I HGabions one to another. to edge or bottom layers or into the adJacen---o'oor fill. according to the conditions of site. structure and forces involved.
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--ABION FILLINGcks and stones should be not less than 4" across and to prevent gapping
hould be placed by hand. largest at the sides and bottom. small stones inhe centre. Appearance will be improved by ensuring that visible facets arened with regular shaped stones.e progress of work is made easier by filling adjoining Gabions equally bytages which also prevents localised overstressing and distortion of thevire.
LACING AND BONDING GABIONShen laying Gabions in rows it is advisable to bond upper layers to theundation Gabions and to join corners in a row with wire to strengthenhe structure and make the faces uniform. Courses should be staggered sohat vertical edges do not coincide. thus spreading stresses'. All adjoiningdges should be wired before filling.
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-'ECIFICATION RANGE OF SIZES vManufactured from hard drawn steel wire. Gridweld Stan-dard Gabions are usually supplied as an assembly ofpanels of 3" x 3 wire mesh in which the wires arewelded at every Intersection. Each panel is connectedby welded rings at 6" spacings ready for folding into abox shape. Wire can be plain finish or heavily galvanisedand of either 5 gauge or 10 gauge according to typeof duty required.
Any size and shape can be supplied to order so longas measurements are in 3" or 2" multiples. In casesof great length it may be found desirable to includea diaphragm across the centre to increase stiffness.The table shown here lists standard sizes of GridweldGabions together with their capacities and the order-ing code for specification.
GRIDWELD GABION SIZES WEIGHTS OF MATERIALS .length - Width - Depth Capacity Ordering Code
Feet Metres. Cu. Yds. Cu. Metres 5gauge 10gauge Fill Material Ibs./cu. ft. Ibs./cu. yd. Ibs./cu. metre6' 0"3' 0"3'0" 18.09 09 2000 1529 G5A Gl0A Basalt 103 2.781 3.6406' 6"3' 3"3'3" 2 11 2616 2000 G5B GlOB9' 9"3' 3"3'3" 31 1 3924 3000 G5C Gl0C Brick 78 2.106 2.75013' 0"3' 31i3.3" 411 5232 4000 G5D Gl0D6' 6" .3' 3".,r9" 2'.105 1308 1000 G5E Gl.oE . Broken CQIlcrete 84 2.268 2.960I' 9"3' 3" i 9" 3.1 05 1'.962 1500 G5F Gl0F -0" 3' '2 : - : . t : 9" 4.1 05 2616 2000 G5G Gl0G Granite 100 2.700 3.53('.JI6' 6" .3' 3''e'l' 0" 21 03 6785 0600 G5H Gl0H9' 9" '.3' 3':'-,t :0" 3103 1177 090d G51 Gl01 Limestone 90 2.430 3.18013' 0"3' 3" t :0" 4103 1570 1200 G5.J Gl0.J6' 0"3' 0" t : 6" 180905 1000 0765 G5K Gl0K Sandstone 87 2.350 3.070FINISH-Plain or galvanised finish should be specified in the order. Shingle 94 2.538 3.320FIXINGS- The correct number of secunng devices are included vvrrheach order Please specify vvhether T clips or helical vvires.DIAPHRAGMS-Please indicate \Nlth each order if and bovv many Slag 94 2.538 3.320diaphragms requ.reo
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Gabions and < :Mattresses
Lid 0utt weldedringsBack
I E ~leoEnd Base .!: Base '-,~ ../0.roi:5 HelicalbindersFront
Construction
WEIGHTS OF FILLING MATERIALS
Material Averagekg/cu. metreBasalt 1650Brick 1240Broken Concrete 1340Granite 1~~Limestone 144... /Sandstone 1390Shingle 1500Slag 1500
Supplied in collapsed form comprising base, four sides, diaphragm(s) and lid. held together by butt welded rings at 300mm centres. Tyingwire and helical binders supplied separately for erection on site. For Gabions and Mattresses over 2 metres long butt welded rings at 375mmcentres. (All mattresses supplied with-lids locce).
Some standard sizesand specificationsNominal Dimensions BRC Weldmesh Specifications
BRCLength Width Depth Capacity Nominal WeldmeshMetres cu. metres Mesh Size Ref. No.4m x lm x 1m 3 diaphragms 43m x 1m x 1m 2 diaphragms 32m x 1m x 1m 1 diaphragm 2lm x lm x lm No diaphragms 1 75mm x 75mm x 5.00mm 354m x 1m x .5m 3 diaphragms 2 75mm x 75mm x 4.00mm 383m x 1m x .5m 2 diaphragms 1.5 75mm x 75mm x 3.00mm 3102m x lm x .5m 1 diaphragm 1 75mm x 75mm x 2.50mm 3126m x 2m x 300mm 5 diaphragms 3.66m x 2m x 225mm 5 diaphragms 2.766m x 2m x 150mm 5 diaphragms 2.04
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This leaflet hasbeenprepared to assistEngineers in the formulation of a Specification and Bill of Quantities fortheuseof Weldmesh Gabion baskets and mattresses.
,,-. Further information is available through the booklet uB.R.C. Weldmesh Gabions and Mattresses", obtainablefrom B.R.C. EngineeringCompany, HeadOffice, Stafford oranyof theCompany's BranchOffices listed on theback pageof this leaflet.A Weldmesh Gabion Advisory Serviceis alsoavailableand B.R.C. will bepleasedto provide further technicalinformation and adviceupon request.
Typical illustration showing the harmonious solution to aesthetic and engineering requrements in rural surroundings by the useofsutable stone-filled mattresses.
CONTENTSInsideFront Cover (Page2)Page4Page5Pages6/7
Standard Sizes, Construction Details etc.Specification Clause.Units of Measurement, Itemisation Clauses.Erection, SiteAssembly Instruction Clauses.
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Q CUTTING AND FOLDING MESH7. Whereshown on theDrawings, orotherwise directed bytheEngineer,thegabionmeshshallbecut, foldedandwired together to form mitre joints, angles, curves or slopes, which arenot possibleto obtain in thestructures with thestandard rectangulargabions, andwherenosuch shapedgabions havebeenpreviouslyspecified. Themeshmust becleanlycut andthe surplus meshcut completely out, orfolded back oron toand neatlywired to, an adjacent gabion face.Thecutedges of themesh shall besecurely lacedtogetherwith tying wire in themannerspecified underErection above. TheAssembly, Erection, Filling and FinalWiring of the re-shapedgabions shall otherwisebecarried out asspecified above.
SPECIAL FINISH8. Where specified by the Engineer, theouter faceof thegabions shall becarefully packedout by handwith
stone of a size100mmto 150mmwhere applicable.PERMEABLE FILTERCLOTH (where applicable)9. Where shown on the Drawings a permeableunderlay as specified under Clause shall beused.
Prior to laying the filter cloth the formation shall be prepared to lineand level for the proposed gabionconstruction with any sharpedgedorprotruding stones removed inordertoform asmooth andsatisfactoryformation to the approval of the Engineer.
'\.......'j NOTE: Above Clausesmay need to bemodified asnecessaryto suit specific contract conditions in
. accordancewith Engineers' andQuantity Surveyors' requirements.
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