WestBridgerATV_Bridge Specs_sps.pdf

SPECIAL PROJECT SPECIFICATIONS

to FP-03 Standard Specifications for

Trail Bridge Fabrication and Installation

June 2009

GALLATIN NATIONAL FOREST

Table of Contents

Section Description Page 260 Geocell Abutment Stabilization 3 557 Timber Structure 6 726 Geocell 11

SPECIAL PROJECT SPECIFATIONS

Preface

Add the following:

The Forest Service, US Department of Agriculture has adopted FP-03 for construction of National Forest System Roads.

Section 260 - Geocell Abutment Stabilization

Description

260.01 Work. Construct geocell abutment stabilization at each abutment using Presto Geoweb Cellular Confinement System, Webtec TerraCell, or approved equal in accordance with the plans and manufacturers recommendations.

Materials

260.02 Requirements. Ensure that material conforms to specifications in the following subsections:

Coarse Granular Backfill 703.03 Geocell 726

Geotextile, Type IV (A, B, C, D, E, or F) 714.01

Construction

260.03 General. Perform the work specified in Section 206. Use ditches, grading or similar methods to prevent surface runoff that may occur during inclement weather from ponding in the foundation excavation.

260.04 Geotextile Installation. Place the geotextile according to AS SHOWN ON THE DRAWINGS. Ensure that the surface upon which the geotextile is to be placed is uniform and is reasonably smooth and free of obstructions, depressions, and debris that could damage the geotextile. Have the surface approved by the CO prior to placing geotextile.

Lay the geotextile without tension, stress, wrinkles or creases. Sew or overlap adjacent strips a minimum of 12” at joints. Insert securing pins through both strips of overlapped geotextile at minimum intervals of 3 feet, but no closer than 2 inches to each edge, to prevent the geotextile from being displaced.

Have the installed geotextile approved by the CO prior to setting the geocells.

260.05 Geocell Installation. Place the geocell sections directly on the prepared subgrade.

Expand the geocell sections into position at the grades and lines AS SHOWN ON THE DRAWINGS. Hold the expanded geocell sections with suitable “stretcher frames”, steel stakes driven inside selected outer cell walls, or other similar methods as allowed by the geocell manufacturer prior to filling. Ensure that the individual cells have been expanded to the minimum dimensions required by the manufacturer. If necessary field cut sections as per the manufacturer’s recommendations to the lines SHOWN ON THE PLANS.

Connect geocell panels in accordance with the manufacturer’s recommendations.

260.06 Infill Placement. Furnish the CO with the manufacturer’s specific recommendations for backfilling prior to placement of the geocells.

Place coarse granular backfill meeting subsection 703.03 into the expanded cells with equipment appropriate for the site conditions such as a backhoe or a front-end loader. Do not drop infill material more than 3 feet to avoid damage or displacement of the cell walls.

Overfill the geocell cells and level to a minimum of 2 inches above the top of the cell walls. A front-end loader may be used to place the infill provided that it only traffics above geocell sections that have been filled and covered with the minimum 2 inches of additional material.

Compact the infill material with a vibratory plate compacter. Operate compaction equipment over the full width of the geocell until visible deformation of the infill ceases. Make at least three complete passes. Grade the surface to be ½ inch above the top of the cells. Ensure that the cell walls are not exposed after fine grading is completed.

Use the geocell manufacturer’s specific recommendations for backfilling if they are more stringent than stated above.

Measurement

260.07 Method. Use the method of measurement that is DESIGNATED IN THE SCHEDULE

OF ITEMS.

Payment will be based on the contract unit price of geocell material placed and accepted. This will be exclusive of wastage and material placed outside the neat lines SHOWN ON THE

PLANS.

Payment

260.08 Basis. The accepted quantities will be paid for at the contract unit price for the PAY

ITEM DESIGNATED IN THE SCHEDULE OF ITEMS.

The cost for furnishing and placing the Coarse Granular Backfill required for geocell infill is incidental to this pay item and no separate payment will be made.

The cost for furnishing and placing geotextile for the geocell installation is incidental to this pay item and no separate payment will be made.

Payment will be made under:

Pay Item Pay Unit

260 (01) Geocell abutment stabilization, __inch depth Square Yard

Section 557 - Timber Structure.

Replace the entire section of the Standard Specification with the following.

Description

557.01 Work. Furnish, fabricate, erect, and paint structural timber, including all required yard lumber and hardware.

557.02 Requirements. Furnish material that conforms to specifications in the following section and subsections:

Hardware & Structural Steel................................................. 716.02 Structural Glued Laminated Timber...................................... 716.04 Treated Structural Timber & Lumber................................... 716.03 Untreated Structural Timber & Lumber................................ 716.01

Furnish the following compliance certificates to the CO upon delivery of the materials to the jobsite:

(a) Verification of compliance with grading rules and species of timber and lumber.

Provide certification by an agency accepted as competent by the American Lumber Standards Committee (ALSC).

(b) Lot certification of each charge for preservative, penetration in millimeters, and retention in kilograms per cubic meter (assay method) by a qualified independent inspection and testing agency. In addition, have the producer of the treated products provide written certification that Best Management Practices (BMP's) in accordance with "Best Management Practices for Treated Wood in Western Aquatic Environments," published by the Western Wood Preservation Institute (WWPI) and Canadian Institute of Treated wood, were followed, including a description and appropriate documentation of the applicable BMP's used.

(c) Certification from a qualified inspection and testing agency indicating that all glued laminated members are in accordance with the requirements of American National Standard for Wood Products, "Structural Glued Laminated Timber" (ANSI/AITC A190.1) modified as SHOWN ON THE DRAWINGS.

(d) Such other certifications as SHOWN ON THE DRAWINGS or called for in the

SPECIAL PROJECT SPECIFICATIONS.

Incise all glued laminated and solid sawn members thicker than 2” in accordance with AWPA standard C1, unless otherwise SHOWN ON THE DRAWINGS.

Provide shop drawings for all timber 21 days in advance of fabrication when SHOWN ON THE DRAWINGS or in the SPECIAL PROJECT SPECIFICATIONS. Show all dimensions and fabrication details for all cut, framed, or bored timbers.

Construction

557.03 General. Furnish structural lumber and timber of the required stress grade.

Clear stacks of weeds, rubbish, or other objectionable material form the ground under and in the vicinity of all stored material. Place the bottom layer of material at lease 8” above the ground level. Provide sufficient support to prevent sagging.

Open-stack untreated material to shed water. Stack material in layers on spacers (stickers) that extend across the full width of the stack to allow for free air circulation. Align all stickers vertically and space them at regular intervals.

Close-stack treated material to shed water.

Protect material from the weather. If covered, used sheet material such as water-resistant paper or opaque polyethylene film. Do not cover with impervious membranes, such as polyethylene film, during dry weather. Slit individual wrappings full length or puncture on the lower side to permit drainage of water.

Store and protect glued laminated timber in accordance with the recommendations for Loading and Handling, Job Site Storage, and Erection in "Recommended Practice for Protection of Structural Glued Laminated Timber During Transit, Storage, and Erection," published by the American Institute of Timber Construction, AITC 111.

Use slings or other devices to protect corners of heavy construction timbers and banded packages of heavy construction timber.

557.04 Treated Timber. Fabricate timbers before treatment. Handle treated timber according to the Consumer Information Sheet published by AWPA. Do not cut, frame, or bore treated timber after treatment unless approved by the CO. Handle treated timbers carefully and do not drop, damage outer fibers, or penetrate the surface with tools. Do not use cant dogs, hooks or pike poles. In coastal waters, do not cut or bore timber below the highwater mark.

Field treat all cuts, abrasions, bolt holes, and recesses that occur after treatment in accordance with the requirements specified in AWPA standard M4, Standard for the Care of Pressure- Treated Wood Products. Plug all unused holes with preservative-treated plugs. Perform all field-applied preservation treatment with necessary precautions so as to prevent and soil and/or water contamination.

557.05 Untreated Timber. Field-treat the following untreated timber surfaces in accordance with AWPA standard M4.

(a) All ends and Tops, and all contact surfaces of posts, sills, and caps.

(b) All ends, joints, and contact surfaces of bracing and truss members.

(c) All surfaces of timber bumpers and the back faces of bulkheads.

(d) All other timber that will be in contact with earth.

557.06 Workmanship. Cut and form all lumber and construction timbers so all joints will have even bearing over the entire contact surface. Do not use shims in makings joints. Construct all joints to be closed. Drive nails and spikes to set the heads flush with the wood surface. Use the same end, face, and edge of the timber member for all layout dimensions. Bore all holes from mating faces.

557.07 Holes for Bolts, Dowels, Rods & Lag Screws. Bore all holes before preservative treating the wood. Bore holes for round driftbolts and dowels 1/16th inch smaller in diameter than that of the bolt or dowel to be used. Ensure that the diameter of holes for square driftbolts or dowels is equal to the side dimension of the bolt or dowel.

Bore holes for machine bolts with a bit 1/16th inch larger than the diameter, except when galvanized bolts are specified. In this case, drill all holes 1/8th inch greater than the bolt size.

Drill the depth of lag screw bolt holes 1 inch less than the length of the screw head and with a diameter approximately 75 percent of the shank diameter.

557.08 Hardware. Furnish the hardware as SHOWN ON THE DRAWINGS, as specified below.

(a) Bolts & Washers. Final tighten all nuts to provide proper bearing, and cut off excess bolt lengths of more than 1 inch. After final tightening, check or burr all bolts effectively with a pointing tool to prevent loosening of the nuts.

Use malleable iron washers with a diameter approximately four times the bolt diameter under all bolt heads or nuts in contact with wood, unless otherwise SHOWN ON THE

DRAWINGS.

(b) Galvanizing. Unless otherwise SHOWN ON THE DRAWINGS, ensure that all hardware for timber structures is galvanized, except for the glued laminated deck panel dowels. Ensure that all fasteners, including nails, spikes, bolts, washers, and timber connectors, other than malleable iron, are galvanized.

557.09 Framing. Do not slab or trim treated piles for fitting sway or sash braces. Fill all gaps that occur between braces and piles with treated blocks so that the bracing is securely fastened to the piles.

557.10 Framed Bents. Mud sills shall be firmly and evenly bedded to solid bearing and carefully tamped in place. Concrete pedestals for the support of framed bents shall be finished carefully so that sills or posts will bear evenly and uniformly over the entire bearing surface.

557.11 Pile Bents. Treat, furnish, and drive piles in accordance with Section 551.

557.12 Caps for All Bents. Make timber caps bear even and uniform over the tops of the supporting posts or piles.

557.13 Bracing. Make all bracings bear firmly against the pile or cap to which it is bolted.

Provide and place shims as necessary to prevent bending the bracing more than 1 inch out of line when bracing bolts are tightened.

Where the space between the bracing and the cap or pile is over 1 inch, use treated wooden shims of the proper thickness. Fabricate the wooden shims from White Oak or from the same treated wood used in the original structure. Do not use built-up wooden shims. Make wooden shims from a single piece of lumber with the width not less than 4 inches and the length not less then the width of the bracing measured along the cap or pile. Do not adzes, trim, or cut any treated member to avoid the use of shims.

557.14 Stringers. Stringers shall be size matched at bearings and shall be positioned so that the camber is up and if possible, so that knots near the edge will be in the top portion of the stringers. Bridging between stringers shall be neatly and accurately framed and securely fastened.

557.15 Glued Laminated Panel Decks. Do not drag or skid panels. When lifted, support panels in the weak-moment plane at a sufficient number of points to avoid overstressing, and protect the edges from damage.

When dowels are SHOWN ON THE DRAWINGS between deck panels, use a template or drilling jig to ensure that dowel holes are accurately spaced and drilled parallel to one another and to the horizontal surfaces of the panel. Drill holes to a depth ¼ inch greater than one-half the dowel length, and a diameter that is 1/16th inch greater than the dowel, unless otherwise SHOWN ON THE DRAWINGS. Use a temporary dowel as a check for snug fit prior to production drilling. Use dowels of the size SHOWN ON THE DRAWINGS, with the tips slightly tapered or rounded. Use an approved lubricant to facilitate the connection process.

Start the tips of all dowels partially and equally into the holes of the two panels being joined.

Draw the panels together keeping the edges parallel, until the panels abut tightly. Securely fasten each panel to each stringer as SHOWN ON THE DRAWINGS.

Assemble and match-mark panels prior to delivery to the construction site when SHOWN ON THE DRAWINGS or called for in the SPECIAL PROJECT SPECIFICATIONS. Follow erection procedures given in FPL-263, Forest Service, Forest Products Laboratory (FPL), Madison, Wisconsin.

Measurement

557.17 Method. Use the method of measurement that is DESIGNATED IN THE

SCHEDULE OF ITEMS.

Measure untreated and treated structural timber and lumber by the board foot measure of lumber and timber in place in the completed structure. Compute the solid sawn structural timber and lumber quantities from nominal dimensions and actual lengths remaining in the completed structure. Compute quantities for glued laminated timber, from actual width, thickness, and length of each piece actually incorporated in the completed structure.

Payment

557.18 Basis. The accepted quantities will be paid for at the contract price for each PAY ITEM

DESIGNATED IN THE SCHEDULE OF ITEMS.

Payment will be made under:

Pay Item Pay Unit

931(01)A Treated Timber Bridge #___________ . . . . . . . . . . . . . . . . . LS

Section 726 - Geocell

Furnish geocell panels consisting of sheet strips fabricated from high-density polyethylene (H.D.P.E.) which are connected in series at off-set, full-depth ultrasonic seams, aligned perpendicular to the longitudinal axis of the strips. When expanded, the interconnected strips form the walls of a flexible, three-dimensional cellular confinement structure into which the specified infill materials can be placed.

Ensure that the polyethylene material used to fabricate the geocell sections is treated to resist ultraviolet degradation and that it conforms to the following:

(a) Density ………………………… 0.935-0.965 g/cm3 per ASTM D1505

(b) Environmental Stress

Crack Resistance (ESCR) ……… 2000 hour per ASTM D1693

Use strips with a sheet thickness, of 1.27 mm -5% +10% (50 mil -5% +10%) tested per ASTM D5199. Thickness shall be determined in the flat, before any surface texturing or other surface disruption.

Ensure that cell seam strength is uniform over the full depth of the cell. Test short-term peel strength per U.S. Army Corps of Engineers Technical Report GL-86-19, Appendix A. Provide a minimum seam peel strength of 2000 N (450 lb) for the 203 mm (8.0 in) depth cell.

Test seam hang-strength for a period of 30 days minimum at room temperature. Room temperature is defined in ASTM E41. Use test samples made by welding two 102 mm (4 in) wide polyethylene strips together. Ensure that a test sample consisting of two carbon black stabilized strips supports a 72.5 kg (160 lb) load for the test period and that a test sample consisting of carbon black stabilized strip and a HALS stabilized strip supports a 63.5 kg (140

lb) load for the test period.

Furnish the CO with a certificate signed by a legally authorized official from the company that manufactured the geocell. Ensure that the certificate attests that the geocell meets the chemical, physical, material and manufacturing requirements stated in the specification. When requested by the CO, furnish a sample of the geocell from each lot for verification testing.

During shipment and storage, wrap the geocell in heavy-duty protective covering. Protect the geocell from mud, soil, dust, debris and sunlight prior to installation.

The following products meet this specification:

GEOWEB manufactured by Presto Products Company, P.O. Box 2399, Appleton, WI 54913- 2399, telephone 920-738-1222.

TERRACELL manufactured by Webtec, Inc., P.O. Box 19729, Charlotte, NC 28219, telephone 704- 398-0954.