HomeMy WebLinkAbout016 RTank SpecificationsPART 1 - GENERAL
1.01 RELATED DOCUMENTS
A.Drawings, technical specification and general provisions of the Contract as modified herein apply to this section.
1.02 DESCRIPTION OF WORK INCLUDED
A.Provide excavation and base preparation per geotechnical engineer's recommendations and/or as shown on the design drawings, to provide adequate support for project design loads
and safety from excavation sidewall collapse. Excavations shall be in accordance with the owner's and OSHA requirements.
B.Provide and install R-TankLD/, R-TankHD/, R-TankSD/, or R-TankU/D/ system (hereafter called R-Tank) and all related products including fill materials, geotextiles, geogrids, inlet and
outlet pipe with connections per the manufacturer's installation guidelines provided in this section.
C.Provide and construct the cover of the R-Tank system including; stone backfill, structural fill cover, and pavement section as specified.
D.Protect R-Tank system from construction traffic after installation until completion of all construction activity in the installation area.
1.03 QUALITY CONTROL
A.All materials shall be manufactured in ISO certified facilities.
B.Installation Contractor shall demonstrate the following experience:
1.A minimum of three R-Tank or equivalent projects completed within 2 years; and,
2.A minimum of 25,000 cubic feet of storage volume completed within 2 years.
3.Contractor experience requirement may be waived if the manufacturer's representative provides on-site training and review during construction.
C.Installation Personnel: Performed only by skilled workers with satisfactory record of performance on bulk earthworks, pipe, chamber, or pond/landfill construction projects of
comparable size and quality.
D.Contractor must have manufacturer's representative available for site review if requested by Owner.
1.04 SUBMITTALS
A.Submit proposed R-Tank layout drawings. Drawings shall include typical section details as well as the required base elevation of stone and tanks, minimum cover requirements and
tank configuration.
B.Submit manufacturer's product data, including compressive strength and unit weight.
C.Submit manufacturer's installation instructions.
D.Submit R-Tank sample for review. Reviewed and accepted samples will be returned to the Contractor.
E.Submit material certificates for geotextile, geogrid, base course and backfill materials.
F.Submit required experience and personnel requirements as specified in Section 1.03.
G.Any proposed equal alternative product substitution to this specification must be submitted for review and approved prior to bid opening. Review package should include third party
reviewed performance data that meets or exceeds criteria in Table 2.01 B.
1.05 DELIVERY, STORAGE, AND HANDLING
A.Protect R-Tank and other materials from damage during delivery, and store UV sensitive materials under tarp to protect from sunlight when time from delivery to installation exceeds
two weeks. Storage of materials should be on smooth surfaces, free from dirt, mud and debris.
B.Handling is to be performed with equipment appropriate to the materials and site conditions, and may include hand, handcart, forklifts, extension lifts, etc.
C.Cold weather:
1.Care must be taken when handling plastics when air temperature is 40 degrees or below as plastic becomes brittle.
2.Do not use frozen materials or materials mixed or coated with ice or frost.
3.Do not build on frozen ground or wet, saturated or muddy subgrade.
1.06 PREINSTALLATION CONFERENCE.
A.Prior to the start of the installation, a preinstallation conference shall occur with the representatives from the design team, the general contractor, the excavation contractor, the
R-Tank installation contractor, and the manufacturer's representative.
1.07 PROJECT CONDITIONS
A.Coordinate installation for the R-Tank system with other on-site activities to eliminate all non-installation related construction traffic over the completed R-Tank system. No loads
heavier than the design loads shall be allowed over the system, and in no case shall loads higher than a standard AASHTO HS20 (or HS25, depending on design criteria) load be
allowed on the system at any time.
B.Protect adjacent work from damage during R-Tank system installation.
C.All pre-treatment systems to remove debris and heavy sediments must be in place and functional prior to operation of the R-Tank system. Additional pretreatment measures may be
needed if unit is operational during construction due to increased sediment loads.
D.Contractor is responsible for any damage to the system during construction.
PART 2 - PRODUCTS
2.01 R-TANK UNITS
A.R-Tank - Injection molded plastic tank plates assembled to form a 95% void modular structure of predesigned height (custom for each project).
B.R-Tank units shall meet the following Physical & Chemical Characteristics:
C.Supplier: ACF West 4390 N. Yellowstone Hwy., Idaho Falls, ID 83401, (208) 881-5070, www.acfwest.com
2.02 GEOSYNTHETICS
A.Geotextile. A geotextile envelope is required to prevent backfill material from entering the R-Tank modules.
1.Standard Application: The standard geotextile shall be an 8 oz per square yard nonwoven geotextile (TenCate Mirafi 180N or equivalent).
2.Infiltration Applications: When water must infiltrate/exfiltrate through the geotextile as a function of the system design, a woven monofilament (TenCate Mirafi FW402 or equivalent)
shall be used.
B.Geogrid. For installations subject to traffic loads and/or when required by project plans, install geogrid (Naue Secugrid 30/30 or equivalent) to reinforce backfill above the R-Tank
system. Geogrid is not always required for R-TankUD/ installations, and is often not required for non-traffic load applications.
2.03 BACKFILL & COVER MATERIALS
A.Bedding Materials: Stone (angular and smaller than 1.5” in diameter) or soil (GW, GP, SW, or SP as classified by the Unified Soil Classification System) shall be used below the
R-Tank system (3” minimum). Material must be free from lumps, debris, and any sharp objects that could cut the geotextile. Material shall be within 3 percent of the optimum moisture
content as determined by ASTM D698 at the time of installation. For infiltration applications bedding material shall be free draining.
B.Side and Top Backfill: Material must be free from lumps, debris and any sharp objects that could cut the geotextile. Material shall be within 3 percent of the optimum moisture content
as determined by ASTM D698 at the time of installation.
1.Traffic Applications - Free draining material shall be used adjacent to (24” minimum) and above (for the first 12”) the R-Tank system.
a.For HD, and SD modules, backfill materials shall be free draining stone (angular and smaller than 1.5” in diameter) or soil (GW, GP, SW, or SP as classified by the Unified Soil
Classification System).
b.For UD modules with less than 14” of top cover, backfill materials shall be free draining stone (angular and smaller than 1.5” in diameter). The use of soil backfill on the sides and top
of the UD module is not permitted unless the modules are installed outside of traffic areas or with cover depths of 14” or more. Top backfill material (from top of module to bottom of
pavement base or 12” maximum) must be consistent with side backfill.
2.Non-Traffic / Green Space Applications - For all R-Tank modules installed in green spaces and not subjected to vehicular loads, backfill materials may either follow the guidelines for
Traffic Applications above, or the top backfill layer (12” minimum) may consist of AASHTO #57 stone blended with 30-40% (by volume) topsoil to aid in establishing vegetation.
C.Additional Cover Materials: Structural Fill shall consist of granular materials meeting the gradational requirements of SM, SP, SW, GM, GP or GW as classified by the Unified Soil
Classification System. Structural fill shall have a maximum of 25 percent passing the No. 200 sieve, shall have a maximum clay content of 10 percent and a maximum Plasticity Index
of 4. Material shall be within 3 percent of the optimum moisture content as determined by ASTM D698 at the time of installation.
2.04 OTHER MATERIALS
A.Utility Marker: Install metallic tape at corners of R-Tank system to mark the area for future utility detection.
PART 3 - EXECUTION
3.01 ASSEMBLY OF R-TANK UNITS
A.Assembly of modules shall be performed in accordance with the R-Tank Installation Manual, Section 2.
3.02 LAYOUT AND EXCAVATION
A.Installer shall stake out, excavate, and prepare the subgrade area to the required plan grades and dimensions, ensuring that the excavation is at least 2 feet greater than R-Tank
dimensions in each direction allowing for installation of geotextile filter fabric, R-Tank modules, and free draining backfill materials.
B.All excavations must be prepared with OSHA approved excavated sides and sufficient working space.
C.Protect partially completed installation against damage from other construction traffic by establishing a perimeter with high visibility construction tape, fencing, barricades, or other
means until construction is complete.
D.Base of the excavation shall be uniform, level, and free of lumps or debris and soft or yielding subgrade areas. A minimum 2,000 pounds per square foot bearing capacity is required.
1.Standard Applications: Compact subgrade to a minimum of 95% of Standard Proctor (ASTM D698) density or as required by the Owner's engineer.
2.Infiltration Applications: Subgrade shall be prepared in accordance with the contract documents. Compaction of subgrade should not be performed in infiltration applications.
E.Unsuitable Soils or Conditions: All questions about the base of the excavation shall be directed to the owner's engineer, who will approve the subgrade conditions prior to placement
of stone. The owner's engineer shall determine the required bearing capacity of the R-Tank subgrade; however in no case shall a bearing capacity of less than 2,000 pounds per
square foot be provided.
1.If unsuitable soils are encountered at the subgrade, or if the subgrade is pumping or appears excessively soft, repair the area in accordance with contract documents and/or as
directed by the owner's engineer.
2.If indications of the water table are observed during excavation, the engineer shall be contacted to provide recommendations.
3.Do not start installation of the R-Tank system until unsatisfactory subgrade conditions are corrected and the subgrade conditions are accepted by the owner's engineer.
3.03 PREPARATION OF BASE
A.Place a thin layer (3” unless otherwise specified) of bedding material (Section 2.03 A), over the subgrade to establish a level working platform for the R-Tank modules. Level to within
½” (+/- ¼”) or as shown on the plans. Native subgrade soils or other materials may be used if determined to meet the requirements of 2.03 A and are accepted by the owner's
engineer.
1.Standard Applications: Static roll or otherwise compact bedding materials until they are firm and unyielding.
2.Infiltration Applications: Bedding materials shall be prepared in accordance with the contract documents.
B.Outline the footprint of the R-Tank system on the excavation floor using spray paint or chalk line to ensure a 2' perimeter is available around the R-Tank system for proper installation
and compaction of backfill.
3.04 INSTALLATION OF THE R-TANKS
A.Where a geotextile wrap is specified on the stone base, cut strips to length and install in excavation, removing wrinkles so material lays flat. Overlap geotextile a minimum 12” or as
recommended by manufacturer. Use tape, special adhesives, sandbags or other ballast to secure overlaps. As geotextiles can be damaged by extreme heat, smoking is not
permissible on/near the geotextile, and tools using a flame to tack the overlaps, such as propane torches, are prohibited.
B.Where an impervious liner (for containment) is specified, install the liner per manufacturer's recommendations and the contract documents. The R-Tank units shall be separated from
impervious liner by a non-woven geotextile fabric installed accordance with Section 3.04A.
C.Install R-Tank modules by placing side by side, in accordance with the design drawings. No lateral connections are required. It is advisable to use a string line to form square corners
and straight edges along the perimeter of the R-Tank system. The modules are to be oriented as per the design drawing with required depth as shown on plans.
1.For LD, HD, and SD installations, the large side plate of the tank should be placed on the perimeter of the system. This will typically require that the two ends of the tank area will
have a row of tanks placed perpendicular to all other tanks. If this is not shown in the construction drawings, it is a simple field adjustment that will have minimal effect on the overall
system footprint. Refer to R-Tank Installation Guide for more details
2.For UD installations, there is no perpendicular end row required.
D.Wrap the R-Tank top and sides in specified geotextile. Cut strips of geotextile so that it will cover the sides and top, encapsulating the entire system to prevent backfill entry into the
system. Overlap geotextile 12” or as recommended by manufacturer. Take great care to avoid damage to geotextile (and, if specified, impervious liner) during placement.
E.Identify locations of inlet, outlet and any other penetrations of the geotextile (and optional liner). These connections should be installed flush (butted up to the R-Tank) and the
geotextile fabric shall be cut to enable hydraulic continuity between the connections and the R-Tank units. These connections shall be secured using pipe boots with stainless steel
pipe clamps. Support pipe in trenches during backfill operations to prevent pipe from settling and damaging the geotextile, impervious liner (if specified) or pipe. Connecting pipes at
90 degree angles facilitates construction, unless otherwise specified. Ensure end of pipe is installed snug against R-Tank system.
F.Install Inspection and Maintenance Ports in locations noted on plans. At a minimum one maintenance port shall be installed within 10' of each inlet & outlet connection, and with a
maximum spacing of one maintenance port for every 2,500 square feet. Install all ports as noted in the R-Tank Installation Guide.
G.If required, install ventilation pipes and vents as specified on drawings to provide ventilation for proper hydraulic performance. The number of pipes and vents will depend on the size
of the system. Vents are often installed using a 90 degree elbow with PVC pipe into a landscaped area with 'U” bend or venting bollard to inhibit the ingress of debris. A ground level
concrete or steel cover can be used.
3.05 BACKFILLING OF THE R-TANK UNITS
A.Backfill and fill with recommended materials as follows:
1.Place freely draining backfill materials (Section 2.03 B) around the perimeter in lifts with a maximum thickness of 12”. Each lift shall be placed around the entire perimeter such that
each lift is no more than 24” higher than the side backfill along any other location on the perimeter of the R-Tank system. No fill shall be placed over top of tanks until the side backfill
has been completed.
2.Each lift shall be compacted at the specified moisture content to a minimum of 95% of the Standard Proctor Density until no further densification is observed (for self-compacting
stone materials). The side lifts must be compacted with walk behind compaction equipment. Even when “self-compacting” backfill materials are selected, a walk behind vibratory
compactor must be used.
3.Take care to ensure that the compaction process does not allow the machinery to come into contact with the modules due to the potential for damage to the geotextile and R-Tank
units.
4.No compaction equipment is permissible to operate directly on the R-Tank modules.
5.Top Backfill: Only low pressure track vehicles shall be operated over the R-Tank system during construction. Dump Trucks and Pans shall not be operated within the R-Tank system
footprint at any time. Heavy equipment should unload in an area adjacent to the R-Tank system and the material should be moved over the system using tracked equipment with an
operating weight of less than 10 tons.
a. Typical Applications: Install a 12” (or as shown on plans) lift of freely draining material (Section 2.03 B) over the R-Tank Units, maintaining 12” between equipment tracks and
R-Tank System. Lightly compacted using a walk-behind trench roller. Alternately, a roller (maximum gross vehicle weight of 6 tons) may be used. Roller must remain in static
mode until a minimum of 24” of cover has been placed over the modules. Sheep foot rollers should not be used.
b. Shallow Applications (< 18” total cover): Install top backfill in accordance with plans.
6.If required, install a geogrid as shown on plans. Geogrid shall extend a minimum of 3 feet beyond the limits of the excavation wall.
7.Following placement and compaction of the initial cover, subsequent lifts of structural fill (Section 2.03 C) shall be placed at the specified moisture content and compacted to a
minimum of 95% of the Standard Proctor Density and shall cover the entire footprint of the R-Tank system. During placement of fill above the system, unless otherwise specified, a
uniform elevation of fill shall be maintained to within 12” across the footprint of the R-Tank system. Do not exceed maximum cover depths listed in Table 2.01 B.
8. Place additional layers of geotextile and/or geogrid at elevations as specified in the design details. Each layer of geosynthetic reinforcement placed above the R-Tank system shall
extend a minimum of 3 feet beyond the limits of the excavation wall.
B.Ensure that all unrelated construction traffic is kept away from the limits of excavation until the project is complete and final surface materials are in place. No non-installation related
loading should be allowed over the R-Tank system until the final design section has been constructed (including pavement).
C.Place surfacing materials, such as groundcovers (no large trees), or paving materials over the structure with care to avoid displacement of cover fill and damage to surrounding
areas.
D.Backfill depth over R-Tank system must be within the limitations shown in the table in Section 2.01 B. If the total backfill depth does not comply with this table, contact engineer or
manufacturer's representative for assistance.
3.06 MAINTENANCE REQUIREMENTS
A.A routine maintenance effort is required to ensure proper performance of the R-Tank system. The Maintenance program should be focused on pretreatment systems. Ensuring these
structures are clean and functioning properly will reduce the risk of contamination of the R-Tank system and stormwater released from the site. Pre-treatment systems shall be
inspected yearly, or as directed by the regulatory agency and by the manufacturer (for proprietary systems). Maintain as needed using acceptable practices or following
manufacturer's guidelines (for proprietary systems).
B.All inlet pipes and Inspection and/or Maintenance Ports in the R-Tank system will need to be inspected for accumulation of sediments at least quarterly through the first year of
operation and at least yearly thereafter.
C.If sediment has accumulated to the level noted in the R-Tank Maintenance Guide or beyond a level acceptable to the Owner's engineer, the R-Tank system should be flushed.
D.All inspection and maintenance activities should be performed in accordance with the R-Tank Operation, Inspection & Maintenance Manual.
R-TANK SPECIFICATION
PROPERTY DESCRIPTION R-TankLD VALUE R-TankHD VALUE R-TankSD VALUE R-TankUD VALUE
Void Area Volume available for water storage 95%95%95%95%
Surface Void Area Percentage of exterior available for infiltration 90%90%90%90%
Vertical Compressive Strength ASTM D 2412 / ASTM F 2418 30.0 psi 33.4 psi 42.9 psi 134.2 psi
Lateral Compressive Strength ASTM D 2412 / ASTM F 2418 20.0 psi 22.4 psi 28.9 psi N/A
HS-20 Minimum Cover Cover required to support HS-20 loads N/A 20”18”12” (STONE BACKFILL)
HS-25 Minimum Cover Cover required to support HS-25 loads N/A 24”19”15” (STONE BACKFILL)
Maximum Cover Maximum allowable cover depth 3 feet < 7 feet < 10 feet 5 feet
Unit Weight Weight of plastic per cubic foot of tank 3.29 lbs / cf 3.62 lbs/cf 3.96 lbs / cf 4.33 lbs / cf
Rib Thickness Thickness of load-bearing members 0.18 inches 0.18 inches 0.18 inches N/A
Service Temperature Safe temperature range for use -14 – 167° F -14 – 167° F -14 – 167° F -14 – 167° F
DRAWN BY
SHEET NO.
TDS
6FOR ADDITIONAL INFORMATION PLEASE CONTACT:ACF WEST, 1-800-423-4567, www.acfwest.com01/09/2023 ENGINEER OF RECORD TO REVIEW, APPROVEAND ENDORSE FINAL SITE SPECIFIC DESIGN.of
DATE
23-001MT
ACF WEST PROJECT NUMBER
6R-TANK SPECIFICATIONTPS-FFISBOZEMAN, MTSITE DESIGNATION: UGDS