Model MSE - Stable Slope Walls System Brochure

Terra Aqua Stable Slope SystemScope: (Stable Slope System)The Terra Aqua Stable Slope System is a mechanically soil reinforced gabion wallfabricated from a continuous double twisted PVC coated mesh that makes up the gabionbox facing and the mesh reinforcement panel. The monolithic design of the Stable SlopeSystem allows the soil reinforcement and the gabion wall to offer strength, durability, andflexibility. Each unit should be placed in direction of maximum strength, which is thedirection the mesh is woven, lying parallel to the direction of soil stress.Unit Sizes:(Gabion Box Facing) Length Width Depth6’ 3’ 3’9’ 3’ 3’12’ 3’ 3’6’ 3’ 1.5’9’ 3’ 1.5’12’ 3’ 1.5’6’ 3’ 1’9’ 3’ 1’12’ 3’ 1’(Mesh Reinforcement Panel)The pvc coated double twisted mesh reinforcement panel width will match the lengthdimension of the gabion box facing, the length or embedment depth of the reinforcementpanel shall be determined by application.Terra Aqua Stable Slope Mechanically Stabilized Earth Gabion WallA. Units1. A.1 Wire Mesha) Polyvinyl chloride coated galvanized steel wire, Class 3, Finish 5, soft, inaccordance with ASTM A641.b) Zinc coated in accordance with ASSTM A641, Class 3, soft, tested inaccordance with ASTM A90.c) Polyvinyl Chloride Coating- All wire used in the fabrication of the units andin the wiring operations during construction shall, after zinc coating, haveextruded onto it a coating of polyvinyl chloride, otherwise referred to asPVC. The coating shall be gray in color unless otherwise specified. Thepvc coating shall be of nominal thickness 0.0216 inches and shallnowhere be less than 0.015 inches in thickness. It shall be capable ofresisting deleterious effects of salt spray, UV rays and abrasion. It shallnot show any significant material difference in its initial characteristicsafter 3000 hours accelerated exposure according to ASTM B117, ASTMD1499 and ASTM G23 and after 200 cycles according to ASTM MethodD1242, Method B.d) Wire core for mesh diameter: 2.7 mmWire core plus pvc coating diameter: 3.8 mmWire core for selvedge- 3.4 mmWire core plus pvc coating for selvedge: 4.5 mmWire core for lacing wire diameter: 2.2 mmWire core plus pvc coating for lacing wire: 3.2 mme) Mesh opening: Nominal 8x10cm (3.25 x 4.50 inches)f) Tensile strength of wire: 60,000 – 75,000 psi according to ASTM A641softg) Tensile strength of pvc mesh: 42.3 kn/m (2900 lbs/ft) minimum pulledparallel to wire twists.B. Tolerances1. Wire- tolerances on the diameter of all wire in the above section shall be subjectto a tolerance of 0.004 inches in accordance with ASTM A641 Table 3.2. Units- tolerances shall be of plus or minus 5% on the manufacturers stated unitdimensions.C. FABRICATION1. Units shall be made from non-raveling, double twisted hexagonal wire mesh. Themesh will have the ability to resist pulling apart at the twists or connectionsforming the mesh when a single wire in a mesh section is cut.2. Units shall be of singe piece construction. They shall be fabricated so that the lid,Front, base and reinforcement panel are continuous and made from the samepanel with no joints. The back face and end panels shall be attached to the basein the factory in such a manner that no additional tying at this juncture shall benecessary.3. All perimeter edges of the mesh forming the units, including end panels tops andinternal diaphragms, shall be terminated with a selvedge wire. For soundstructural integrity the unit mesh wires shall be wrapped around the selvedgewire with a minimum of one and one half turns.D. Wire Mesh Tests1. Elongation- If test shall be made they shall be made on the wire beforefabrication of the units on a sample 12 inches long. Elongation shall not be lessthan 12%.2. Strength- The wire mesh shall not rupture when subjected to a load of 27 kn(6000 lbs) when applied as follows:a) Clamp a section 2 meters 6’ long, not less than 1 meter 3’ wide includingselvedge bindings, for 1 meter along the width, or in the middle of widthsgreater than 1 meter, with the excess falling free on each side.b) Apply tension to elongate the section 10%.c) Apply the load, 27kn (6000 lbs) as stated above, to a 0.093 square meterare located approximately in the center of the sample between theclamps. The direction of the load should be perpendicular to the tensionforce direction an be applied with a circular ram bead with the edgesbeveled or rounded to prevent cutting the wires.E. Gabion Basket Filling1. The gabion basket facing shall be filled with hard, durable stone fill varying indimensions from 4” – 8” in diameter. The rock shall not exceed 50% wear asdetermined by AASHTO Designation: T96. The rock shall not exceed 12%weighted loss after five cycles of the sodium sulfate soundness of aggregate testAASHTO Designation: T104.F. Assembling1. Units shall be assembled and erected according to manufacturer’s instructionsand project specifications. Units are supplied folded flat and packed in bundles.Single units shall be removed from the bundle, unfolded on a hard flat surface,and have all kinks and bends worked out before assembly. The reinforcementpanels may be left folded up until the baskets are placed in position. The unitshall then be assembled individually by erecting the front and back, ends anddiaphragms, ensuring that all creases are in the correct position and the tops ofall sides satisfactorily.2. The four corners of the unit shall be connected first followed by the edge wires ofinternal diaphragms to the sides. The edge seam connection and thediaphragms to side connection should be accomplished by using lacing wire orapproved interlocking fasteners.3. Acceptable lacing wire has been described in previous Section A, paragraph A.1.d The recommended procedure to apply lacing wire consists of cutting asufficient length of lacing wire, approximately 1.4 – 1.5 meters (4.5” – 5”) long. LSecure one end of the wire by looping and twisting, then proceed to lace withalternating single and double loops at approximately 5 inch intervals. Thensecurely fasten the other end of the lacing wire. This procedure shall develop ajoint strength of 1200 lbs / ft for PVC and 1400 lbs / ft for galvanized gabions.4. The installation of recommended fasteners should be carried out in accordancewith the contract specifications. Acceptable fasteners for joining PVC coatedunits shall be formed from 0.120 inch minimum diameter stainless steel wirehaving high tensile strength and shall conform to ASTM A313, Type 302, Class1. Fasteners shall produce a four-wire selvedge joint of 1200 lbs / ft for PVCand 1400 lbs / ft for galvanized gabions, while remaining locked or overlapped aminimum of 1 inch.G. Installation and Placement 1. The assembled units are carried to the job site and placed in their properlocation. For structural integrity, the adjoining empty units must be securelyjoined together using the same connecting procedures described in Section F,paragraph 3 and 4 along with the vertical edges and the top edge of theircontract surfaces in order to obtain a monolithic structure. An approved cornerclosure tools shall be used to adjoin adjacent gabions to insure a tight neat seamand minimize gabion wire joint deformation. 2. The reinforcement panels are then unfolded onto the compacted backfill. It is notnecessary to attach the reinforcement panels to each other with lacing wire orfasteners except at one point approximately 3’ behind the back panel foralignment purposes. 3. After the lower tier of units is filled, closed and the backfill compacted, the nexttier of units is placed on top and shall be connected to the lower tier along thefront edge of the contact surface, using the same connecting proceduredescribed in Section F, F.3 and 4.H. Filling 1. Units shall be filled with stone as described in Basket Fill Section E. 2. Units may be filled by almost any type of earth handling equipment. Somemanual stone adjustment during the filling operation is required to minimizevoids. It is also recommended that the stone against the exposed faces of theunits be hand-stacked to give a neat, compact and attractive appearance. Careshall be taken when placing fill material to assure that the sheathing of the PVCcoated units will not be broken or damaged. The stone should not be dumpedfrom a height greater than 2’ – 3’ above the top of the gabion units. 3. The individual cells of the units in any row shall be filled in stages so that localDeformation may be avoided. That is, at no time shall any cell be filled to adepth exceeding 1’ more than an adjoining cell. It is also recommended toslightly overfill the gabion on approximately 2” – 4” above the top of the gabionunit to allow for settlement. 4. Well-packed filling of units without undue bulging, and secure lacing and/orfastening, is essential in all structures.I. Filter Fabric Placement 1. Filter Fabric shall be placed so as to completely cover the back of the unit with 1’of excess material to be folded toward the backfill at both the top and bottomalong the reinforcement panels. The fabric shall be attached to the top of theback panel with either lacing wire or approved fasteners every 18 inches. Thetype of fabric will be dependent upon the fill material furnished. The fabric shallbe selected based upon gradation samples and approved by the DesignEngineer.K. Internal Connecting Wires 1. Internal connecting wires are used to prevent the front face of the units frombulging as additional rows or layers are placed on top of the existing layers. 2. 3’ high units shall be filled in three layers 1’ at a time. After the placement ofeach layer, two connecting wires shall be placed to connect the exposed face ofa cell to the opposite side of the cell. The wire shall be looped around two meshopenings and the ends of the wires shall be securely twisted to prevent itsloosening. An exposed front face is any side of a cell that will be exposed orunsupported after the structure is completed. 3. 1.5’ high units shall be filled in two layers 9” at a time. After the placement ofeach layer two connecting wires shall be placed to connect the exposed face of acell to the opposite side of the cell. L the wire shall e looped around two meshopenings and the ends of the wire shall be twisted to prevent its loosening.L. Lid closing 1. The lid shall be stretched tight over the filling of the stone until the lid meets theperimeter edges of the unit. This operation shall be accomplished by using anapproved lid closing tool. The lid shall then be tightly fastened along all edges,ends and tops of the diaphragms in the same manner as described in Section F,F.3 and F.4. 2. Upon completion, the structure shall be checked and all ends of wire shall befolded into the structure. Well-packed filling without undue bulging and securelacing and/or fastening is essential in all structures.All Terra Aqua gabion material is manufactured according to ASTM A975-97 guildelinesfor Double Twisted Hexagonal Mesh Gabions.ASTM A975-75Terra Aqua Gabions, Inc.1415 N. 32nd StreetFort Smith, AR 72904800-736-9089