Filtrexx Trinity Wire MSE Living Retaining Wall System

Transcription

1 . 3SECTION 3: LIVING WALLS Filtrexx Trinity Wire MSE Living Retaining Wall System PURPOSE & DESCRIPTION Trinity LivingWall system allows for the stabilization of walls and slopes with variable inclinations between 45 degrees and 80 degrees. The system s galvanized wire facing elements allow for mechanical connection and reinforcement while providing structure and containment of Filtrexx GroSoxx and vegetation. Through the use of GroSoxx, the Trinity LivingWall system provides superior soil retention and erosion protection while providing an optimum environment for vegetation establishment. APPLICATION Constructing a Trinity LivingWall involves stacking GroSoxx on top of one another inside the wire facing elements in a recessed fashion on steep slopes to near vertical situations. Various strengths of polymer straps Figure 3.1. Example of Trinity LivingWall Installation; Location: Kromrey Middle School, Middleton, WI are looped through the bottom of the facing elements and pulled taught into the structural backfill giving it added structural support and integrity to meet specific structural and site requirements. Although the primary objective of the Trinity Living- Wall system is to stabilize earth and reduce erosion, the secondary objective is to provide for the establishment and sustainability of vegetation and an aesthetic landscape feature. This goal is evidenced through the design and function of the wall fascia of GroSoxx as well as the Filtrexx GrowingMedia that fills the wall fascia. The Trinity LivingWall can be used for a wide variety of structural applications including: Wall and steep slope stabilization Streambank stabilization Pond bank stabilization Slip repairs Culvert headwalls Bridge abutments Dikes/berms Sound barriers ADVANTAGES AND DISADVANTAGES Advantages Trinity LivingWall has greater surface contact with soil and bank slopes, relative to block or other wire systems, thereby providing greater protection from erosion Easily reinforced for severe slope applications Lightweight components Two sizes of wire available to accomodate residential landscape and commercial applications Highly efficient installation; certified available Improved drainage/reduction of hydrostatic pressure Trinity LivingWall system includes GrowingMedia, which establishes, sustains, and provides reinforcement for vegetation, unlike rip rap and other hard armoring devices Trinity LivingWall is comprised of GrowingMedia, which is organic, all natural and locally manufactured 352 Filtrexx Low Impact Design Manual Version 10.0

2 3.3. Filtrexx Trinity LivingWall Customizable vegetation with seed injection into GroSoxx, plants, plugs, or live stakes Trinity LivingWall can be direct seeded at the time of installation Ability to irrigate with low flow, low pressure drip tape Trinity LivingWall stability and bank protection/ erosion prevention are increased by vegetation establishment Vegetated Trinity LivingWall filters sediment, soluble nutrients, heavy metals, petroleum hydrocarbons, pesticides, and pathogens from storm runoff flowing toward surface waters GrowingMedia in Trinity LivingWall has the ability to bind and adsorb soluble nutrients, metals, and hydrocarbons that may be in storm water runoff, thereby reducing loading to adjacent receiving waters Vegetated Trinity LivingWall removes pollutants from storm water by plant uptake Microorganisms in GrowingMedia have the ability to degrade organic pollutants and cycle captured nutrients into beneficial and/or less toxic forms Humus colloids and organic matter in GrowingMedia provide physical structure for seed, seedlings, and live stakes Humus colloids and organic matter in GrowingMedia provide increased water holding capacity and reduced water evaporation to aid in seed germination, plant sustainability, and the potential for reduced irrigation GrowingMedia provides organic nutrients that are slowly released for optimum vegetation establishment GrowingMedia provides organic nutrients that Installation Difficulty Structural Stability ADVANTAGES Vegetation Establishment Erosion Control Aesthetic Quality LOW MED HIGH ü ü ü ü ü are less prone to runoff transport and pollution of surface waters, relative to mineral nutrients supplied by fertilizers Trinity LivingWall can be easily designed and incorporated as one treatment in a treatment train approach to site or watershed storm water management Contained GrowingMedia within Trinity LivingWall GroSoxx creates an ideal system for biotechnical engineering projects Disadvantages If Trinity LivingWall does not use GrowingMedia, performance may be diminished If not installed correctly, maintained or used for a purpose or intention that does not meet specifications, performance may be diminished Trinity LivingWall should not be the only form of site or watershed storm water management Trinity LivingWall may need to be reseeded or live stakes replaced if establishment is poor Trinity LivingWall installation is a land disturbing activity and can increase sediment loading to surface waters if appropriate sediment control measures are not established during the construction phase MATERIAL SPECIFICATIONS Trinity LivingWall primary components are: galvanized wire facing panels and supports, GroSoxx, GrowingMedia, mechanically connected polymer strap reinforcement and rollers, and vegetation. These components, when installed correctly, work together to establish a stabilization system of reinforced vegetation. For Design drawing details of the Trinity LivingWall system see Figures 3.1 and 3.2. Galvanized Wire Facing Panel & Supports Trinity Landscape system wire facing pieces are 3-ft wide by 1.5-ft tall by 1.5-ft rearward. Trinity Commercial system wire facing pieces are 10-ft wide by 1.5-ft tall by 1.5-ft rearward. Each face piece is composed of longitudinal and transverse W4.5 wire spaced at 6-inches on center. Trinity wire facing pieces are pre-bent to form a natural 70 slope facing angle once installed. All wire components in Trinity face pieces are welded in accordance with ASTM A1064/ A1064M/A185/A185M. All wire components in Trinity face pieces are galvanized in accordance with AASHTO M232 or M111 and ASTM A123. Trinity wire facing pieces interlock side to side in each running course, as well as interlock front to back with the top course of each facing piece interconnecting LID Section 3: Living Walls 353

3 with the bottom of the face piece of the next upper course. Galvanized wire support struts are fastened into each face piece on 2-ft centers to guarantee the shape and integrity of each face piece and proper alignment to create the 70 slope facing. Filtrexx GroSoxx GroSoxx is the tubular mesh netting material specifically designed to retain GrowingMedia, seed and other materials. This finished product, stacked within the wire facing during construction, promotes healthy vegetation growth. Moisture flows freely to both reduce hydrostatic pressure and increase drainage of subsurface moisture to the vegetated fascia. The openings in GroSoxx mesh are such that they allow for root growth for healthy vegetation while retaining GrowingMedia to prevent soil loss. GroSoxx wall fascia units are available in 12-in (300mm) diameter and are constructed of a variety of materials and characteristics (see Table 3.1). GroSoxx of various lengths are installed in layers within the wire facing elements, reducing the number of breaks in the system that might occur compared to other block structures. These continuous sections allow the GroSoxx fascia to act as a solid, seamless beam across the slope, further distributing any acting pressures. To ensure quality, GroSoxx should be manufactured by a Filtrexx Certified sm manufacturer. GrowingMedia Characteristics Trinity LivingWalls use only Filtrexx GrowingMedia which is a composted material that is specifically designed for stability within the system and establishment and sustainability of vegetation growth. GrowingMedia can be third party tested and certified to meet minimum performance criteria defined by Filtrexx International. Performance parameters include: percent cover of vegetation, water holding capacity, ph, organic matter, soluble salts, moisture content, biological stability, maturity bioassay, percent inert material, bulk density and particle size distribution. For information on the physical, chemical, and biological properties of GrowingMedia refer to Filtrexx GrowingMedia Specifications in Section 5.28 of the Appendix. Polymer Strap Reinforcement & Rollers Inextensible polymer straps are a commonly used component for soil stabilization. Trinity LivingWall may be installed using a variety of strengths to meet the requirements of the project. The junction of polymer strap reinforcement to wire is protected by an integrated strap roller piece that is snapped onto each wire at the strap connection position. Typical strap reinforcement designs will yield approximately three connected straps per 10-ft wide Commercial wire face piece on every course. Typical strap reinforcement designs will yield approximately one connected strap per 3-ft wide Landscape wire face piece on every course. DESIGN CRITERIA Vegetation Choices Turf/forage grasses perennial/annual rye mix, tall fescues Groundcovers Vinca minor, English ivy, winter creeper Live shrub cuttings willows, dogwoods Native species Vines, etc. Sedum Methods for Establishing Vegetation GroSoxx incorporated with seed Live staking Broadcast seeding Plugs Vegetation Selection Successful planning for any vegetation establishment project should consider aesthetics, wildlife habitat, climate, prevailing weather, temperature, sun exposure, prolonged moisture exposure, available moisture/irrigation requirements, topography, soil type, soil ph, soil amendments, nutrient requirements, drought tolerance, time/coordination with construction phases, site preparation/ coordination with construction phases, protection from erosion and sedimentation, concentrated flow and runoff velocity potential, maintenance, and seed mix/plant selection. Note: If in doubt regarding vegetation, Filtrexx International should be consulted. Quick establishing annual grasses and legumes are normally specified for temporary and nurse crop applications when necessary. Perennial grasses are typically specified for permanent applications, and if possible native grasses should be utilized (Fifield, 2001; USDA-NRCS, 2004) as these will be better adapted to local climate, native soil, and hydrology. Trinity LivingWall is specifically designed for biotechnical engineering applications. GrowingMedia fill within the sock system creates an optimum fertile and structural environment for establishing and sustaining live stakes, tubers, rhizomes, and plugs. A live stake is a 1 to 3-ft long cutting from a live 354 Filtrexx Low Impact Design Manual Version 10.0

4 3.3. Filtrexx Trinity LivingWall hardwood tree or shrub and planted vertically into a growing media (KYTC, 2006). Typical live stake species include, willow, poplar, maple, cottonwood, dogwood, sycamore, and oak (KYTC, 2006). Drip tape irrigation installed within the Trinity LivingWall system maintains moisture for plants used in biotechnical engineering projects, particularly in drought prone regions and seasons. Local landscape architects, NRCS, or cooperative extension should be consulted and used as resources for seed and plant selection. Many state erosion and sediment control and storm water management manuals have specifications for seed and plant selection, seeding rates, and planting requirements. VegSpec, a design program created by the USDA- NRCS, may be a helpful tool for seed and plant selection. It can be accessed at Establishing & Sustaining Vegetation Trinity LivingWall is seeded at the time of application by injection or premixing seed into the GroSoxx. Nurse crops, such as annual rye, may be considered to establish a quick vegetative cover and root anchor until perennial grasses and/or live stakes are established. Taller grasses may have higher sediment removal efficiency and sediment storage capacity, and a greater ability to dissipate runoff energy and reduce storm flow velocity relative to low growing or low maintained grasses. Live stakes should be 1 to 3-ft long and planted vertically with at least 2-in of one end planted into a growing media, and spaced 3 to 5-ft apart (KYTC, 2006). Although GrowingMedia typically has a higher water holding capacity than topsoil, irrigation may be required to ensure successful establishment. In arid and semi-arid regions or hot and dry weather regular irrigation may be required. Drip tape irrigation may be installed within the Trinity LivingWall GroSoxx to maintain moisture within GrowingMedia for establishing vegetation or in drought prone regions and seasons. Trinity LivingWall GrowingMedia supplies humus, organic matter, beneficial microbes, and slow release organic nutrients that can contribute to increased fertility, plant health and sustainability. Organic vs. Fertilizer Nutrients Although most specification and design manuals include fertilizer recommendations or requirements for vegetation, mineral nutrients from fertilizers may not be preferable where vegetation sustainability and water quality are a concern. Trinity LivingWall provides organic nutrients which are slowly released, provide plant micronutrients, and are less likely to be transported in storm runoff to receiving waters which can lead to pollution and eutrophication of waterways (Faucette et al, 2005). Weed Establishment Invasive weed growth has been more closely associated with mineral fertilizer than organic fertilizer fertility practices (Faucette et al, 2004). Vegetation practices should always be inspected for invasive and noxious weeds. INSTALLATION Trinity LivingWall shall meet Filtrexx Trinity Living- Wall Specifications and use Filtrexx GroSoxx. Excavation Contractor shall excavate to the lines and grades shown on the construction drawings, and comply with all local, state, and federal regulations. Leveling Pad Foundation soil shall be excavated to the depth and location as per site plans. Remove any unsuitable soil and replace with approved fill and compact to 95% standard Proctor maximum dry density. Construct leveling pad in horizontal terraces. Base Course/Unit Installation Install the first course on the leveling pad and in accordance with procedures on the plans. Drainage Pipes Drain pipes are to be installed so as to run to daylight, at low points, and along wall alignment to a maximum spacing of 50-ft. Reinforcement The principle reinforcement component is a woven and coated polymer strap. Once units within a coarse are placed the strap shall be inserted from the top through the wire frame and pulled through to the mid-point of its total length, prior to filling the module. The strap may now be pulled into the backfill zone for each connected module of the course. Straps must lay horizontal at the same elevation as the base LID Section 3: Living Walls 355

5 of the unit. Terminal ends of the strap should be the same distance from the module and spread 30-in apart. In sequence, units should be filled with GroSoxx, then mass backfill shall be placed in a rearward direction, starting from the units moving toward the rear of the fill zone. Construction equipment shall not be operated directly on the straps. Select Fill Fill shall be placed in 6-in lifts and compacted to 95% Proctor maximum dry density. No heavy compaction equipment shall be used within 3-ft of the rear of the modules. Backfill shall be placed and compacted to minimize movement of reinforcement components. Finished grade above the structure shall be graded to direct all water away from the wall, unless specifically designed to accept storm water runoff. Site Drainage All surface drainage should be directed away from the wall. Excess water can cause washouts and erosion. Proper drainage and erosion control measures should be adhered to until final stabilization and inspection. INSPECTION Field reviews to ensure seed and/or plant establishment should occur at regular intervals after seeding or planting to assure germination and/or coverage of the Trinity LivingWall System. Trinity LivingWall should also be inspected after initial rainfall/runoff events to ensure drainage is functioning appropriately and hydrostatic pressure has not compromised the system. At six months if 70% uniform coverage has not occurred it is recommended that reseeding or remedial planting be performed. MAINTENANCE The Trinity LivingWall system requires very little maintenance providing appropriate vegetation types are selected and drainage is addressed during the design and build stages. In arid climates or for use during the establishment stages, low volume, low pressure drip tape may be installed as part of the Trinity LivingWall system to ensure hydration to the vegetation. For complete information on irrigation systems, refer to Filtrexx Support Practices in section 3.9. For specific maintenance requirements in your area please contact Filtrexx International. Installation of Filtrexx Trinity LivingWall. Bid prices shall be based on a per ft 2 or m 2 of fascia and shall include the supply and installation of the following: GroSoxx vegetated with site specific seed or plantings GroSoxx /aggregate/soil backfill as needed. Galvanized wire facing as needed, support struts, strap reinforcement and strap rollers Filtrexx Compost Stormwater Control Blanket around extremities of system ADDITIONAL INFORMATION For other references on this topic, including additional research reports and trade magazine and press coverage, visit the Filtrexx website at Filtrexx International, Technical Support 61 N Clev-Mass Rd, Ste E, Akron, OH (fax) info@filtrexx.com Call for complete list of international installers. BactoLoxx, DuraSoxx, EnviroBloxx, EnviroSoxx, Filtrexx, GardenSoxx, GreenLoxx, GroSoxx, Let Nature Do It, MetalLoxx, NutriLoxx, PetroLoxx, and Trinity are Registered Trademarks of Filtrexx International. BioSoxx, CECB [Compost Erosion Control Blanket], CSWB [Compost StormWater Blanket], DitchChexx, EdgeSaver, FilterCell, FilterMedia, FilterSoxx, GrowingMedia, InletSoxx, LivingWall, Lockdown, NitroLoxx, PhosLoxx, SiltSoxx, Soft Blocks, and Soxx are Trademarks of Filtrexx International. Filtrexx Certified and its accompanying logo are Service Marks of Filtrexx International. The information contained herein may be subject to confidential intellectual property of Filtrexx International, including but not limited to US Patents 7,226,240; 7,452,165; 7,654,292; 8,272,812; 8,439,607; 8,740,503; 8,821,076; and 9,044,795 or Patents Pending and is the property of Filtrexx International. Copyright , Filtrexx International, all rights reserved. Unauthorized reproduction prohibited. METHOD OF MEASUREMENT Trinity LivingWall shall be itemized as Supply and 356 Filtrexx Low Impact Design Manual Version 10.0

6 3.3. Filtrexx Trinity LivingWall REFERENCES Faucette, L.B., K. Kerchner, and A. Vick Sediment Storage Capacity of SiltSoxx vs. Silt Fence. Filtrexx Tech Link #3314. Faucette, L.B., H. Keener, M Klingman, and K. Kerchner Design Capacity Prediction Tool for SiltSoxx and Silt Fence. Filtrexx Tech Link #3313 (description) and Filtrexx Library #301 (design tool). Faucette, L.B., and A. Vick LEED Green Building Credits using Filtrexx Organic BMPs. Filtrexx Tech Link #3301. Faucette, L.B. A. Vick, and K. Kerchner Filtrexx, Compost, Low Impact Development (LID), and Design Considerations for Storm Water Management. Filtrexx Tech Link #3306. Faucette, L.B Flow-Through Rate, Design Height, and Design Capacity of SiltSoxx and Silt Fence. Filtrexx Tech Link #3304. Faucette, L.B Design Height, Flow-Through Rate, and Slope Spacing of SiltSoxx and Silt Fence. Filtrexx Tech Link #3311. Faucette, L.B., and R. Tyler Organic BMPs used for Storm Water Management. Proceedings of the International Erosion Control Association Annual Conference, Long Beach, CA Filtrexx Tech Link #3302. Faucette, L.B., N. Strazar, and A. Marks Filtrexx Polymer and Flocculent Guide. Filtrexx Library #601. Faucette, B., Sadeghi, A., and K. Sefton USDA ARS - Evaluation of Compost Filter Socks and Silt Fence in Sediment and Nutrient Reduction from Runoff. Filtrexx Tech Link #3308. Fifield, J Designing for Effective Sediment and Erosion Control on Construction Sites. Forester Press, Santa Barbara, CA. Keener, H., B. Faucette, and M. Klingman Flow-through rates and evaluation of solids separation of compost filter media vs. silt fence in sediment control applications American Society of Agricultural and Biological Engineers Annual International Conference, Portland, OR. Paper No US EPA NPDES Phase II Compost Filter Socks: Construction Site Storm Water Runoff Control. National Menu of Best Management Practices for Construction Sites. npdes/stromwater/menuofbmps/con_site.cfm Faucette, B, F. Shields, and K. Kurtz Removing storm water pollutants and determining relations between hydraulic flow-through rates, pollutant removal efficiency, and physical characteristics of compost filter media. Second Interagency Conference on Research in Watersheds, 2006 Proceedings. Coweeta Hydrologic Research Station, NC. Filtrexx Library #106. Faucette L.B., C.F. Jordan, L.M. Risse, M. Cabrera, D.C. Coleman, and L.T. West Evaluation of Storm Water from Compost and Conventional Erosion Control Practices in Construction Activities. Journal of Soil and Water Conservation. 60:6: Faucette, L.B Removal and Degradation of Petroleum Hydrocarbons from Storm Water with Compost. Filtrexx Tech Link #3307. Faucette, L.B A Comparison of Performance and Test Methods of SiltSoxx and Silt Fence. LID Section 3: Living Walls 357

7 TABLES & FIGURES: Table 3.1. Filtrexx Soxx Material Specifications. Material Type Multi-Filament Polypropylene (HDPP) Multi-Filament Polypropylene SafteySoxx Multi-Filament Polypropylene DuraSoxx Material Characteristic Design Diameters Photodegradable Photodegradable Photodegradable 8 in (200mm), 12 in (300mm), 18 in (400mm), 24 in (600mm), 32 in (800mm) 8 in (200mm), 12 in (300mm), 18 in (400mm), 8 in (200mm), 12 in (300mm), 18 in (400mm), 24 in (600mm), 32 in (800mm) Mesh Opening 3/8 in (10mm) 1/8 in (3mm) 1/8 in (3mm) Tensile Strength 44 psi (3.09 kg/cm2) 202 psi (14.2 kg/cm2)* 202 psi (14.2 kg/cm2) % Original Strength from Ultraviolet Exposure 100% at 1000 hr 100% at 1000 hr 100% at 1000 hr (ASTM G-155) Functional Longevity/ Project Duration** 1-4 yr 2-5 yr 2-5 yr * Tested at Texas Transportation Institute/Texas A&M University (ASTM ). ** Functional Longevity based on continual UV exposure without vegetation. Once vegetation is established longevity of the system is greatly increased. Functional longevity ranges are estimates only. Site specific environmental conditions may result in significantly shorter or longer time periods. 358 Filtrexx Low Impact Design Manual Version 10.0

8 3.3. Filtrexx Trinity LivingWall TABLES & FIGURES: Table 3.2. Filtrexx Smart Strap Specifications. Properties/Type Unit 20kN (FW20) 30kN (FW30) 50kN (FW50) 70kN (FW70) Materials Core Polyester Polyester Polyester Polyester Sheath Polyethylene Polyethylene Polyethylene Polyethylene Thickness mm 1.8± ± ± ±0.3 Weight g/lm 120±10% 140±10% 210±10% 250±10% Tensile Strength* kn/full Width >20 >30 >50 >70 Elongation* % <12 <12 <12 <12 Width mm 90±5 90±5 90±5 90±5 Roll Length LM 100~ ~ ~ ~150 *Test Method for Tensile Strength and Elongation: ASTM D 4595 All Quality Control of the above Products are in accordance with AZ/NZX ISO 9001:2000 Standards. LID Section 3: Living Walls 359

9 Figure 3.2. Filtrexx Trinity LivingWall Typical Thru Wall Detail - Commercial Figure 3.3. Filtrexx Trinity LivingWall Isometric Detail - Commercial 360 Filtrexx Low Impact Design Manual Version 10.0

10 3.3. Filtrexx Trinity LivingWall Figure 3.4. Filtrexx Trinity LivingWall Typical Thru Wall Detail - Landscape Figure 3.5. Filtrexx Trinity LivingWall Isometric Detail - Landscape LID Section 3: Living Walls 361