593GEOTEXTILE

New Hampshire Department of Transportation Standard Specifications – 2016 Description

1.1This work shall consist of furnishing and installing geotextile fabric as shown on the plans or as ordered, including any labor

and materials needed to anchor, splice, or repair the geotextile. Materials

2.1General.

2.1.1 Geotextile shall be a product tested under the AASHTO National Transportation Product Evaluation Program (NTPEP) and included on the Qualified Products List for the Application, Strength Class, and Structure specified. Manufactures of geotextiles and those marketing geotextiles made by others as a “ Private Labeler” shall participate in and maintain compliance with the NTPEP audit program for geotextiles. Manufacturer’s labels providing product name, AASHTO M288 class, roll number, and production date shall be affixed to both ends of the roll. 2.1.2 All geotextile properties referenced in the specifications and certified by the Contractor , with the exception o f Apparent Opening Size (AOS), shall be considered minimum average roll values in the weaker principal direction (i.e., the average test results for any sampled roll in a lot shall meet or exceed the minimum values specified). Values for AOS shall represent maximum average roll values. 2.1.3 Fibers used in the manufacture of geotextiles, and threads used in joining geotextiles by sewing, shall meet the requirements of the most current version of the applicable sections of AASHTO M 288. 2.1.4 Geotextile shall exhibit an ultraviolet stability (retained strength) of at least 50% after 500 hours of exposure, measured in accordance with ASTM D 4355.

2.2Application.

Following are the basic Applications of geotextile included under this specification. Applic ations are described according to their most common use(s) and may not include every function for which a geotextile is specified. 2.2.1 Application 1 – Subsurface Drainage. Geotextile for this Application consists of fabric placed against a soil to allo w for long-term passage of water into a subsurface drain system while retaining the in situ soil. 2.2.2 Application 2 – Separation. Geotextile for this Application consists of fabric placed to prevent mixing of in situ or subgrade soil with aggregate cover materials. 2.2.3 Application 3 – Stabilization. Geotextile for this Application consists of fabric placed in wet, saturated conditions to provide the coincident functions of separation and filtration. This Application may also be specified for geotextiles used to provide the function of reinforcement. 2.2.4 Application 4 – Permanent Erosion Control. Geotextile for this Application consists of fabric placed below riprap or other armor systems to prevent soil loss and/or instability of the erosion control system.

2.3Strength Class. Following are the basic Strength Classes of geotextile included under this specification:

2.3.1 Class 1, Class 2, and Class 3. Geotextile specified as Class 1 (high strength), Class 2 (medium strength), or Class 3 (low strength) shall meet the applicable requirements of AASHTO M 288, Table 1, including sewn seam strength when sewn seams are used. A higher strength geotextile may be substituted for a lower strength geotextile provided all other specification requirements are met. 2.3.2 Class 0. Geotextile specified as Class 0 (extra high strength) shall meet the following minimum requirements: Geotextile Property Test Method Property Requirement Pounds Grab Tensile Strength ASTM D 4632 375 Sewn Seam Strength ASTM D 4632 335 Tear Strength ASTM D 4533 135 Puncture Strength ASTM D 6241 1237

2.4Structure. The Contract Item Number for geotextile includes a designation for Structure that defines the basic composition

of the fabric. Geotextile shall conform to the specified structure as identified by the Item Number.

2.5Permittivity and Apparent Opening Size (AOS). Geotextile shall meet the requirements for permittivity and Apparent

Opening Size (AOS) as described in the Geotextile Qualification Criteria Document. Located on the Department’s Website.

New Hampshire Department of Transportation Standard Specifications – 2016

2.6Each roll shall be clearly labeled so as to easily identify the product in the field. The label shall include as a minimum t he

manufacturer’s name, product name and number, and the Contract Item name and number.

2.7Staples or Pins. Staples or pins required to hold the geotextile prior to placing overlying materials shall be those prescribed

by the geotextile manufacturer. Construction Requirements

3.1Protection of Geotextile. To prevent damage to the fabric, the Contractor shall exercise necessary care while transporting,

storing, and installing the fabric. Prior to installation, the fabric shall be protected from weather, direct sunlight or ot her ultra- violet exposure, and from dust, mud, dirt, debris, and other elements which may affect its performance. Fabric that is torn, punctured, or otherwise damaged shall not be placed. After placement, fabric shall be covered within 5 days. Traffic or construction equipment shall not be permitted directly on the geotextile.

3.2Placement of Geotextile and Overlying Materials. The geotextile and overlying materials shall be placed in accordance

with the plans, the manufacturer's requirements, and the following: 3.2.1 General. Prior to placement of the fabric, the site shall be prepared to provide a smooth surface which is free from debris, obstructions, and depressions which could result in gaps, tears, or punctures in the fabric during cover operations. 3.2.1.1 Successive sheets placed above water shall be over lapped by a minimum of 18”. Sheets placed below water shall be sewn or overlapped by a minimum of 3 feet. Larger overlaps may be called for on the plans or required by the Engineer in soft soil conditions or if gaps between adjacent sheets occur during placement of overlying material. Pins or staples may be used to anchor the fabric as directed by the Engineer. 3.2.2 Subsurface Drainage. Trench excavation shall be done in accordance with details shown on the plans. In all instances, excavation shall be done in such a way so as to prevent large voids from occurring in the sides and bottom of the trench. 3.2.2.1 The geotextile shall be placed loosely with no wrinkles or folds, and with no void spaces between the geotextile and the ground surface. Successive sheets shall be shingled such that the upstream sheet is placed over the downstream sheet. 3.2.2.2 Placement of drainage aggregate shall proceed immediately following placement of the geotextile. T he geotextile shall be covered with a mi nimum of 12” of loosely placed aggregate prior to compaction. If a collector pipe is to be installed in the trench, a bedding layer of drainage aggregate shall be placed below the pipe, with the remainder of the aggregate placed to the minimum required construction depth. 3.2.2.3 After placing the drainage aggregate, the geotextile shall be folded over the top of the aggregate in a manner that produces the overlap shown on the plans. In no case shall the minimum overlap be less than 12”. 3.2.3 Separation/Stabilization. The installation site shall be prepared by clearing, grubbing, and removal of vegetation and topsoil. The site shall be excavated or filled to the proper grade as shown on the plans or as ordered. The Engineer may order that soft spots and unsuitable areas identified during site preparation or subsequent proof rolling be excavated, backfilled, and compacted with suitable materials. 3.2.3.1 The geotextile shall be laid smooth without wrinkles or f olds on the prepared subgrade, except that it may be folded or cut to conform to curves. Joints and overlaps shall be in the direction shown on the plans or as ordered by the Engineer. The folds or overlaps shall be held in place by pins, staples, or piles of fill or rock. 3.2.3.2 Overlying fill or aggregate materials shall be placed by end dumping onto the geotextile from the edge of the geotextile, or over previously placed materials. Construction vehicles shall not be allowed directly on the geotextile. Materials shall be placed such that at least the minimum specified lift thickness is between the geotextile and equipment tires or tracks at all times. Turning of vehicles shall not be allowed on the first lift above the geotextile. 3.2.3.2.1 On very soft subgrades, the fill or aggregate shall be spread to the proper li ft thickness as soon as possible after dumping to minimize the potential of localized subgrade failure due to concentrated loading. 3.2.3.2.2 In stabilization applications, vibratory compaction equipment on the initial lift of fill or aggregate material may be prohibited by the Engineer to prevent damage to the geotextile. 3.2.3.3 Placement procedures that result in instability or damage to the geotextile shall be modified to eliminate further damage. The Engineer may order remedial measures such as increasing the initial lift thickness or decreasing equipment loads. 3.2.3.4 Geotextile placed below temporary fills shall be completely removed immediately after the fill is removed. Geotextile salvaged from use under temporary fills shall not be used for any permanent application in the project unless approved by the Engineer. 3.2.4 Permanent Erosion Control. The geotextile shall be placed in intimate contact with the soils without wrink les or folds, and anchored on a smooth graded surface approved by the Engineer. The geotextile shall be placed in such a manner that placement New Hampshire Department of Transportation Standard Specifications – 2016 of the overlying materials will not excessively stretch or tear the geotextile. Anchoring of the terminal ends of the geotextile shall be accomplished through the use of key trenches or aprons at the crest and toe of the slope as shown on the plans. 3.2.4.1 The geotextile shall be placed with the machine direction (long direction of the roll) parallel to the dire ction of water flow, which is normally parallel to the slope for erosion control runoff and wave action, and parallel to the stream or chann el in the case of stream bank and channel protection. When overlapping, the fabric shall be placed such that the up hill sheet is placed over the downhill sheet, and the upstream sheet is placed over the downstream sheet. In cases where wave action or multidirectional flow is anticipated, all seams perpendicular to the direction of flow shall be sewn. 3.2.4.2 The armor system placement shall begin at the toe and proceed up the slope. Placement shall take place so as to avoid stretching, puncturing, and tearing of the geotextile. Particles smaller than 1.5 cubic feet , shall be placed with drop heights less than 3 feet. Particles greater than 1.5 cubic feet shall be placed with no free fall. Drop heights exceeding the distance specified above may be allowed by the Engineer if field tests demonstrate that larger drop heights will not result in damage to the fabric. In no case shall stones be rolled or pushed onto the geotextile. 3.2.4.3 The geotextile and armor materials shall be placed the same day in underwater applications. 3.2.4.4 Field monitoring shall be performed to verify that the armor system placement does not damage the geotextile. Fabric which is damaged as a result of careless or improper placement of stone, grading techniques, or equipment traffic above the s tone shall be repaired or replaced in accordance with 3.3.

3.3Repair of Geotextile. Fabric that is damaged during or after placement shall be replaced or repaired by stitching or patching

at the expense of the Contractor . Patches shall be of the same material as the placed geotextile. The patch shall be joined to the existing fabric using overlapped seams as specified above or as directed by the Engineer. 3.3.1 The Contractor shall modify his placement or covering procedures to eliminate further or repeated damage from occurring.

3.4Sewn Seams. Sewn seams, if specified, ordered, or allowed, shall result in a joint at least as strong as the sewn seam strength

requirements described in 2.3. Field or factory seaming will be permitted unless otherwise specified. Sewn seams shall be lapped a minimum of 4” and double sewn using Stitch Type 401 a s depicted in ASTM D 6193. Either a “ J” seam (Type SSn-2) or “ Butterfly” seam (Type SSd-2) shall be used as shown in Figure 1. 3.4.1 All seams shall be subject to the approval of the Engineer. Sewn seams shall be positioned on the exposed side of th e fabric to allow for inspection and/or repair of the fabricated joint. Seams shall not be positioned as shown in Figure 2.

FIGURE 1

New Hampshire Department of Transportation Standard Specifications – 2016

FIGURE 2 Method of Measurement

4.1Geotextile will be measured by the square yard as determined by the actual surface measurem ents of the covered area.

Additional material used for overlaps and repairs will not be measured. Basis of Payment

5.1The accepted quantity of geotextile will be paid for at the Contract unit price per square yard for the application, strength

class, and structure specified, complete in place. The cost of all labor or materials used to anchor, splice, or repair the geotextil e is considered subsidiary to the geotextile installation. Removal of temporary geotextile will be considered subsidiary to th e geotextile installation. Pay Item and Unit: 593.A B C Square Yard

Key: A= Application 1 = Subsurface Drainage 2 = Separation 3 = Stabilization 4 = Permanent Erosion Control B = Strength Class 0 = Class 0 1 = Class 1 2 = Class 2 3 = Class 3 C = Structure 0 = Contractor Option 1 = Nonwoven (Default for Application 1 & Application 4) 2 = Monofilament, Woven 3 = Slit Filament, Woven

New Hampshire Department of Transportation Standard Specifications – 2016

Description

This work shall consist of furnishing and installing, or removing and relaying, pipes, pipe end sections, pipe sleeves, and

post installation video inspection at the locations shown or ordered, including the n ecessary joints, fittings, and connections as required. Sawed pavement, common structure excavation to the depth specified i n 206.4.1, secondary excavation required in the imperfect trench method, bedding, shaping of bedding, and backfill shall be included in this work. Materials

Reinforced Concrete Pipe, Circular.

2.1.1 Fabricator Certification. Concrete pipe manufacturing plants shall be certified by the American Concrete Pipe Association through its “ Quality Cast” plant certification program. The Fabricator shall submit proof of certification at delivery. 2.1.2 This pipe shall conform to the requirements of AASHTO M 170, except as follows: When fly-ash is used, only Class F, in accordance with AASHTO M 295 will be allowed. Wall A thickness will be allowed in Class III pipe only. When the plans call for reinforced concrete pipe capable of withstanding an ultimate load greater than 3750 D, the design requirements of Class V shall be met with further provision that the pipe will withstand the ultimate D-load specified. 2.1.3 Basis of acceptance of concrete pipe shall confor m to AASHTO M 170 , Section 5.1.1. Test requirements shall be as provided in Section 11 with the further provision that the pipe will wit hstand an additional ten percent of the D -load specified or brought to destruction. Permissible variation in pipe tolerances shall confor m to AASHTO M 170, Section 12. 2.1.4 Workmanship and finish shall confor m to AASHTO M 170, Section 12. Pipe shall be subject to rejection on account of failure to conform to any of the specification requirements of AASHTO M 170, Section 15. Individual sections of pipe may be rejected for the following reasons:

position in the wall of the pipe.

exposed at the ends will not be cause for rejection if a satisfactory joint can be made.

Table 603-1 - Minimum Strength Requirements D Load to produce the ultimate load = Class D Load to produce a 0.01 crack

AASHTO Designation Class 1500D 1000D II 2000D 1350D III 3000D 2000D IV 3750D 3000D V 4000D ---- --- 2.1.5 Markings on pipe shall conform to AASHTO M 170, Section 16 with the following information clearly marked on each section of pipe.

2.1.6 Concrete pipe shall be joined by using flexible water tight gaskets conforming to AASHTO M 198.

Corrugated Metal Pipes and Pipe-Arches--Steel.

2.2.1 Except as provided below, steel pipes and pipe-arches shall conform to AASHTO M 36, Type I or II.