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Home My WebLink About3211721130011-09102014BUILDING DEPARTMENT SEP - 9 2014 SPECIFICATIONS FOR POROUS INTERLOCKING CONCRETE PAVEMENT CITY JF EDINA CONSTRUCTION OF POROUS PAVEMENT Proper construction of porous pavement is critical to its long term performance as a stormwater BMP. Improper or inadequate erosion and sediment control during construction and immediately following construction can cause immediate plugging of the pavement. The construction sequence is also critical to the long term success of the performance of the pavement and is described below. Failure to follow the recommendations will likely cause premature structural failure of the pavement or result in pavement without the desired infiltration capacity. EROSION AND SEDIMENT CONTROLS FOR PERMIABLE PAVEMENT All porous pavement areas should be fully protected from sediment intrusion by silt fence or construction fencing, particularly if they are intended to infiltrate runoff. They should remain outside the limit of disturbance during construction to prevent soil compaction by heavy equipment. Porous pavement areas should be clearly marked on all construction documents and grading plans. To prevent soil compaction, heavy vehicular and foot traffic should be kept out of porous pavement areas during and immediately after construction. During construction, care should be taken to avoid tracking sediments onto any porous pavement to avoid surface clogging. Any area of the site intended ultimately to be a porous pavement area should generally not be used as the site of a temporary sediment basin. Where locating a sediment basin on an area intended for porous pavement is unavoidable, the invert of the sediment basin must be a minimum of one foot above the final design elevation of the bottom of the aggregate reservoir course. All sediment deposits in the excavated area should be carefully removed prior to installing the sub -base, base, and surface materials. INSTALLATION OF INTERLOCKING PAVERS The basic installation process is described in greater detail by Smith (Smith 2011). Porous paver job foremen should (not required) successfully complete the PICP Installer Technician Course training program offered by the Interlocking Concrete Pavement Institute (ICPI). The ICPI provides a variety of technical courses. The following installation method also applies to clay paving units. Contact manufacturers of composite units for additional installation specifications. Guide construction specifications are available from the Interlocking Concrete Pavement Institute. • Moisten, place and level the AASHTO No. 2 stone subbase and compact it in minimum 12 inch thick lifts with four passes of a 10 -ton steel drum static roller until there is no visible movement. The first two passes are in vibratory mode with the final two passes in static mode. The filter aggregate should be moist to facilitate movement into the reservoir course. • Place edge restraints before the base layer, bedding and pavers are installed. Porous interlocking pavement systems require edge restraints to prevent vehicle tires from moving the pavers. Edge restraints may be standard concrete curbs or curb and gutters. • Moisten, place and level the AASHTO No. 57 base stone in a single lift (4 inches thick). Compact it into the reservoir course beneath with at least four (4) passes of a 10 -ton steel drum static roller until there is no visible movement. The first two passes are in vibratory mode, with the final two passes in static mode. • Place and screed the bedding course material (typically AASHTO No. 8 stone (MnDOT 3127 -FA -3), 2 inches thick). • Pavers may be placed by hand or with mechanical installation equipment. • Fill gaps at the edge of the paved areas with cut pavers or edge units. When cut pavers are needed, cut the pavers with a paver splitter or masonry saw. Cut pavers no smaller than one-third (1/3) of the full unit size if subject to tires. • Fill the joints and openings with stone. Joint openings must be filled with AASHTO No. 8 (MnDOT 3127 -FA -3), 89 or 9 (MnDOT 3127 FA-2)stone per the paver manufacturer's recommendation. Sweep and remove excess stones from the paver surface. • Compact and seat the pavers into the bedding course with a minimum low -amplitude 5,000 Ibf, 75- to 95 Hz plate compactor. Do not compact within 6 feet of the unrestrained edges of the pavers. • Thoroughly sweep the surface after construction to remove all excess aggregate. • Inspect the area for settlement. Any paving units that settle must be reset and inspected. • The contractor should return to the site within 6 months to top up the paver joints with stones. CONSTRUCTION INSPECTION Inspections before, during and after construction are recommended to ensure that porous pavement is built in accordance with these specifications. The following checklist provides typical inspection observation items: Pre -construction meeting 1. Walk through site with builder/contractor/subcontractor to review erosion and sediment control plan/stormwater pollution prevention plan (SWPPP). 2. Determine when permeable pavement is built in project construction sequence; before or after building construction and determine measures for protection and surface cleaning. 3. Aggregate material locations identified (hard surface or on geotextile). Sediment management 4. Access routes for delivery and construction vehicles identified. 5. Vehicle tire/track washing station location/maintenance (if specified in the erosion and sediment control plan (SWPPP)). 6. Ensure that the contributing drainage areas are stabilized and are not eroding. Excavation 7. Utilities should be located and marked by local service provider. 8. The excavated area should be marked with paint and/or stakes. 9. The excavation size and location should conform to the plan. 10. Excavation hole as sediment trap: The hole cleaned should be cleaned immediately before subbase stone placement and runoff sources with sediment diverted away from the pavement or all runoff diverted away from the excavated area. 11. Temporary soil stockpiles should be protected from run-on, run-off from adjacent areas and from erosion by wind. 12. Ensure linear sediment barriers (if used) are properly installed, free of accumulated litter, and built up sediment less than 1/3 the height of the barrier. 13. No runoff should enter the pavement until soils are stabilized in the area draining to the pavement. 14. Foundation walls should be waterproofed 15. Soil subgrade: rocks and roots removed, voids should be refilled with base aggregate. 16. Soil should be compacted to specifications (if required) and field tested with density measurements per specifications. 17. No groundwater seepage or standing water. If groundwater seepage is present, dewatering and possibly a dewatering permit may be required. Geotextiles 18. Must meet the design specifications. 19. Sides of excavation should be covered with geotextile prior to placing aggregate base/subbase. 20. Placement and down slope overlap (minimum of 2 feet) should conform to specifications and drawings. 21. No tears or holes should be present. 22. No wrinkles should be present and the fabric should be pulled taught and staked. 23. Impermeable liners (if specified) 24. Must meet the specifications. 25. Placement, field welding, and seals at pipe penetrations should be completed per the design specifications. 26. Drain pipes/observation wells. 27. Size, perforations, locations, slope, and outfalls must meet specifications and drawings. 28. Verify the elevation of overflow pipes. 29. Underdrains should be capped at upslope ends. Aggregates 30. Test results should conform to specifications. 31. Aggregates should be spread (not dumped) with a front-end loader to avoid aggregate segregation. 32. Storage on hard surface or on geotextile to keep sediment -free. 33. Thickness, placement, compaction and surface tolerances should meet specifications and drawings. Installation 34. See Installation of Interlocking Pavers section. CONCRETE PAVERS; 3" DEPTH TYPICAL JOINT FILLER, AASHTO No. 8 BEDDING COURSE; 2" DEPTH, AASHTO No. 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 » °°°°°0°°°°°o°°°0°°°0° 0 0°°°0°0°°°0°0°° BASE COURSE, 4 DEPTH, AASHTO No. 57 SUB -BASE COURSE, AASHTO No. 2, 3, OR 4 10 DEPTH FOR DRIVEWAY 6" DEPTH FOR SIDEWALK OR PATIO GEOTEXTILE MIRAFI 50OX OR EQUAL PREPARED SUBGRADE NATIVE SOIL TYPICAL SECTION POROUS INTERLOCKING CONCRETE PAVEMENT NOTES: 1. ALL STONE IS TO BE WASHED FREE OF FINES. 2. PLACE GEOTEXTIEE ON BOTTOM AND SIDES OF EXCAVATION. SPECIFICATIONS FOR SOIL AMENDEMENT BY SOIL RIPPING SOIL AMENDMENT BY SOIL RIPPING TO RELIEVE COMPACTION: a)Ripping (Subsoiling) should be performed using a solid -shank ripper and to a depth of 18 inches as measured from the top of topsoil. b)The goal of soil ripping or subsoiling is to fracture compacted soil without adversely disturbing plant life, topsoil, and surface residue. Soil compaction occurs most frequently with soils having a high clay content. Fracturing compactedsoil promotes root penetration by reducing soil density and strength, improving moisture infiltration and retention, and increasing air spaces in the soil. Compacted layers typically develop 12 to 22 inches below the surface when heavy equipment is used. c)Subsoilers (rippers) can break up the compacted layer without destroying soil aggregate structure, surface vegetation, or mixing soil layers (Kees, 2008). How effectively compacted layers are fractured depends on the soil's moisture, structure, texture, type, composition, porosity, density, and clay content. Success depends on the type of equipment selected, its configuration, and the speed with which it is pulled through the ground. No one piece of equipment or configuration works best for all situations and soil conditions, making it difficult to define exact specifications for subsoiling equipment and operation. d)Subsoilers are available with a wide variety of shank designs. Shank design affects subsoiler performance, shank strength, surface and residue disturbance, effectiveness in fracturing soil, and the horsepower required to pull the subsoiler. According to Kees (2008), "Parabolic shanks require the least amount of horsepower to pull. In some forest applications, parabolic shanks may lift too many stumps and rocks, disturb surface materials, or expose excess subsoil. Swept shanks tend to push materials into the soil and sever them. e)Ripping, subsoiling, or scarification of the subsoil should be performed where subsoil has become compacted by equipment operation, dried out and crusted, or where necessary to obliterate erosion rills. f) Subsoiling should not be performed within the drip line of any existing trees, over underground utility installations within 30 inches of the surface, where trenching/drainage lines are installed, where compaction is by design. g)Subsoiling is only effective when performed on dry soils. If soils are saturated, the Contractor shall delay operations until the soil will not hold a ball when squeezed. Only one pass shall be performed on erodible slopes greater than 1 vertical to 3 horizontal. When only one pass is used, work should be at right angles to the direction of surface drainage, whenever practical. �It . Liek , 42 vlw m s�bf d CONSTRUCTION SEQUENCE. a)Subsoil ripping, or scarification of the subsoil will be required wherever the subsoil has been compacted by equipment operation or has become dried out and crusted, and where necessary to obliterate erosion rills. Sub -soiling shall be completed in areas as indicated on the plan where plant establishment or grass turf is planned. b)Install perimeter, and/or down gradient, erosion control BMP's prior to any upslope land disturbance. c)Rough grading of the project should be complete and measured implemented to protect the soil ripping area from experiencing further compaction by heavy equipment. d)Existing topsoil shall be stripped from the area of soil ripping work. Topsoil shall be stockpiled and temporary erosion control measures shall be implemented as required for the stockpile. e)The subsoil shall be in a relatively dry, friable condition to a depth of 18 inches below final topsoil grade. f) Ripping channels shall be created by a commercially available, multi-shanked, parallelogram implement (solid -shank ripper or equivalent equipment). The equipment shall be capable of exerting a penetration force s necessary for the site. The grid channels shall be paced a minimum of 12 inches to a maximum of 36 inches apart. The channel depth shall be a minimum of 18 inches. g)Sub-soiling shall be completed such that ripping channels result in a two -directional grid. h)Topsoil shall be re -spread over the soil ripping subsoil area at a minimum 6" depth. i) Final grade of the soil ripping area shall be achieved by use of light equipment with tracks or turf type tires. Equipment with high pressure narrow tires or large lugs will cause excessive compaction. j) Permanent ground cover turf shall be established by sod or seed with established growth before perimeter erosion control BMP's are removed. Erosion control BMP's are to be removed once final stabilization is achieved. C*m43tj#P� ah,`k GRAPHIC FROM MPCA MINNESOTA STORM WATER MANUAL SOIL AMENDMENT AREA STORM WATER CALCULATION SUMMARY. o)Proposed soil amendment area is 1,250 sf. b)Soil type is Hydrologic Group B per NRCS Web Soil Survey data. c)Reference MPCA Stormwoter Manual, Comparison of Average Annual Runoff Grouped By Soil Type And Conditioning, Average Annual Runoff Depth. Average annual runoff depth for compact Group B soils = 5.2 inches. Average annual runoff depth for loose soils = 4.7 inches. Result of soil amendment by loosing is 0.5 inches. Propose to achieve loose soil condition by soil ripping. d)Storm water runoff volume reduction due to soil loosening for this project: 1,250 sf x 0.5 inches / 12 in/ft = 52.0 cf. e)Proposed house and site improvements as noted on Sheet 1 result in increase of 163 sf hard surface that drains to rear yard area. f) Proposed soil amendment provides for reduction of stormwater volume control equivalent to 3.9 inch rainfall event on 163 sf hard surface. 52 cf / 163 sf x 12 in/ft = 3.8 inches CLIENT: CORNERSTONE HOMES, LLC 5609 Warden Avenue Edina, MN 55436 612-598-5255 d' 4 C m CcC 0 0 Z IL J m m O m Q W �•- 30♦♦♦ V ` cc Z c O o 0 NG 9) to 0 O W W d' 4 .► 0 C, � m m O m Q W 's W W 0 0 0 FILE N0. 00499 � Q J Q � Q II �Z �I W .c �Q WWW oo� W �., Q�x vv0o� �ONNN 20 II > N 4,- Z _ ^ ` O O O d' 4 .► 0 C, � m m O m W W 's W W 0 0 0 FILE N0. 00499 2/2 Storm Water and Erosion Control Plan