145GEOSYNTHETIC REINFORCEMENT

145-1Description

This Section specifies the construction requirements for geosynthetics used in: geosynthetic reinforced soil slopes, and geosynthetic reinforced foundations constructed on soft in-situ soils. Furnish and place geosynthetics and any associated facing material or drainage blankets.

145-2Responsibility

Construct the geosynthetic reinforced feature, including materials, method, and installation based on information provided in the Contract Documents and the geosynthetic supplier’s recommendations. Submit shop drawings in accordance with Section 5 showing the details and distribution of the selected geosynthetics that meet the design shown in the Plans. Alternate designs optimizing the selected geosynthetic materials may be submitted. For alternate designs, submit complete design calculations and details which include plan view, elevation view, and details in accordance with the Contract Documents. These shall show the extent, numbe r of layers of geosynthetic reinforcement, minimum properties of each geosynthetic reinforcement layer, vertical spacing of geosynthetic reinforcement, orientation of geosynthetic facing details, details at special structures or obstructions, typical const ruction sequence, and top and bottom elevations of the geosynthetic reinforcement. Calculations shall be submitted to substantiate the design meets the requirements of Chapter 263 of the FDOT Design Manual and in accordance with the Plans. As a minimum , these shall clearly show the derivation of reinforcement requirements (i.e., type, spacing, length, etc.) and determination of all design parameters and factors. All plans and calculations are to be signed and sealed by a Professional Engineer registered in the State of Florida.

145-3Materials

145-3.1Geosynthetic Materials: Use materials meeting the requirements of Section 985

and are listed on the Approved Product List (APL) . Deliver geosynthetic materials (including facing and drainage elements) to th e job site in unopened shipping packages labeled with the supplier’s name and product name. During shipping and storage, protect the geosynthetic from physical damage, debris and from temperatures greater than 140°F. Follow the supplier’s recommendations r egarding protection from direct sunlight. At the time of installation, the Engineer will reject the material if it has defects, tears, punctures, flaws, deterioration, or other damage. However, if approved by the Engineer, the Contractor may repair torn or punctured sections by placing a patch over the damaged area. Replace or repair any rejected geosynthetic at no additional expense to the Department.

145-3.2Backfill Materials: Use only free draining backfill material in the reinforced fill

volume as sho wn in the Plans meeting the following gradation limits as determined in accordance with AASHTO T 27 and FM 1-T011:

Table 145-1 Sieve Size Percent Passing 3-1/2 inches 100 205 FY 2023-24 Return to Table of Contents

Table 145-1 Sieve Size Percent Passing 3/4 inch 70 to 100 No. 4 30 to 100 No. 40 15 to 100 No. 100 5 to 65 No. 200 0 to 15

Do not use backfill material containing more than an average of 2.0% by weight of organic material, as determined by FM 1-T267 and by averaging the test results for three randomly selected, representative samples from each stratum or stockp ile of a particular material. Consider the stratum or stockpile unsuitable for construction of the reinforced fill volume if an individual test value exceeds 3.0%. Use backfill with a maximum plasticity index of six as determined by AASHTO T 90, and a ma ximum liquid limit of 15 as determined by AASHTO T 89. Use backfill materials with a pH between 4.5 and 10.0 as determined by FM 5-550. When metal pipes or other metal items are embedded in the backfill, use backfill with a pH between 6.0 and

10.0Do not use soil cement or lime stabilized backfill unless approved by the Engineer

Have the backfill material tested for every soil type for pH by a Department approved independent testing laboratory prior to placement. Submit a signed and sealed certification by a Professional Engineer registered in the State of Florida, that the results have met the requirements of this Section.

145-4Construction

145-4.1General: Obtain from the geosynthetic supplier, technical instructions, guidance

in preconstruction activities, and on -site technical assistance during construction. Submit a copy of any instructions provided by the supplier to the Engineer prior to beginning installation.

145-4.2Reinforced Soil Slopes:

145-4.2.1 Preparation: Remove all existing vegetation and all unsuitable foundation materials. Prepare the foundation in accordance with Section 110, except as noted herein. Proof roll the graded area with a vibratory roller weighing a minimum of 8 tons or a sheepsfoot roller, where appropriate, exerting a compression of at least 250 psi on the tamper foot for at least five passes in the presence of the Engineer or as directed by the Engineer. Remove and replace any soft or loose foundation subsoils that are, in the opinion of the Engineer, incapable of sustaining the required proof rolling, in accordance with Section 125. Provide proof rolled ground surfaces which are uniform, smooth, and free of abrupt changes in slope, debris, and irregularities that might damage the reinforcement. Promptly repair and restore to their original condition any areas outside the l imits of disturbance shown in the Plans which are damaged as part of this work at no expense to the Department. Make every possible effort to avoid such damage. 145-4.2.2 Geosynthetic Placement: Place the geosynthetics at the proper elevation, location a nd orientation as shown in the Plans. In general, place the geosynthetics used for slope stabilization such that its primary direction of tensile strength is perpendicular to the plan face of the slope. Pull the geosynthetic material tight, and secure it a s necessary to lay flat against the soil prior to fill placement. 206 FY 2023-24 Return to Table of Contents

Place adjacent rolls of geosynthetic to maintain 100% horizontal coverage at the face of the slope. When placing geosynthetic for curved embankments, do not allow less than 50% horizontal coverage or an unreinforced horizontal spacing greater than 3 feet at the end of the reinforcement farthest from the face of the slope. Do not allow vertical spacing of the geosynthetic layers to exceed the spacing shown on the shop drawings. Do not ma ke any splices or seams in the primary direction of tensile strength in the geosynthetic without approval of the Engineer. When splices in the primary direction are approved, make splices full width of the geosynthetic strip by using a similar material wit h similar strength. Use a splice mechanism that allows a minimum of 95% load transfer from piece to piece of geosynthetic. Make only one splice per length of geosynthetic. Do not place splices within 6 feet of the slope face, within 6 feet below top of slo pe, or horizontally adjacent to another splice. Place only that amount of geosynthetic material, including facing and drainage material, which will be covered in a single days’ production. Do not operate equipment directly on the geosynthetics. Opera te equipment such that no turning movements occur on the areas where geosynthetic is in place with less than 12 inches of fill cover. Fill and compact ruts of more than 3 inches in depth as they develop. 145-4.2.3 Backfill Placement: Perform work in acco rdance with an approved QC Plan meeting the requirements of 105 -3. A LOT is defined as a single lift of finished embankment not to exceed 500 feet in length. Maintain uniform moisture content of the backfill material prior to and during compaction througho ut each layer of material. Use backfill material having a placement moisture content within 2% on the dry side of optimum. Do not place wet backfill with moisture content greater than optimum in the fill. Spread backfill material over the geosynthetic in t he direction of geosynthetic overlaps. Do not stockpile backfill materials on the installed geosynthetics. Avoid construction procedures or equipment which, in the opinion of the Engineer, will cause excessive mudwaving. Compact the backfill using eithe r smooth wheel or rubber tire rollers. Do not use sheepsfoot, grid rollers, or other types of equipment employing a foot. At the end of each day’s operation, slope the backfill surface in order to permit runoff of rainwater away from the slope face, or pro vide some other positive drainage. Do not exceed the maximum allowable lift thickness in Section 120. 145.4.2.4 Repairs: Replace geosynthetic reinforcement damaged during or after installation at no expense to the Department. Repair geosynthetics damaged during or after installation only after the supplier establishes that the interior and exterior stability is not affected and after obtaining the Engineer’s approval. Make such repairs as follows: Remove all backfill material from the damaged area of t he reinforcement geosynthetic plus an additional 4 feet in all directions beyond the limits of damage. Place a patch consisting of the same material as the reinforcement geosynthetic over the damaged area. Overlap the undamaged reinforcement geosynthetic w ith the patch a minimum of 3 feet in all directions. Then replace and compact backfill material in accordance with 145 -4.2.3.

145-4.3Reinforced Foundations Constructed on Soft In -Situ Soils:

145-4.3.1 Preparation: For some applications involving reinfo rcement of soft insitu soils, the Engineer may require that some vegetation be left in place. If directed in the Plans or by the Engineer, cut trees to within 6 inches of the existing surface, and leave the stumps in place. Remove fallen trunks, limbs, etc . greater than 3 inches in diameter. 207 FY 2023-24 Return to Table of Contents

145-4.3.2 Backfill Placement: Meet the requirements of 145 -4.2.3. 145-4.3.3 Geosynthetic Placement: Position and orient the geosynthetics over prepared surfaces. Place a geotextile filter of a type recommended by th e designer of the geosynthetic system under the reinforcement geosynthetic. Cut and overlap geosynthetics as necessary to accommodate curves. Overlap or join ends and sides of adjacent geosynthetic courses as shown in the Plans and in accordance with 145 -4.2.2. Make any overlaps in geosynthetics in the same direction that covering embankment will be spread. Take care to ensure that the geosynthetic sections do not separate at overlaps during construction. Pull the geosynthetic material tight by hand to a te nsion that removes all slack. 145-4.3.4 Repairs: Meet the requirements of 145 -4.2.4.

145-5Certification

Submit certification from the supplier, at least ten days prior to placement, that the products used are the same products listed on the APL, are in accordance with the project design requirements and is recommended by the supplier for use at this location. Acceptance of furnished material will be based on the supplier ’s certification and visual inspection by the Engineer.

145-6Acceptance Program

145-6.1General Requirements: Meet the requirements of 120 -10 except delete the

requirements of 120 -10.1.4.1, 120 -10.1.6, 120 -10.2 and 120 -10.3.

145-6.2Maximum Density Determination: Determine the maximum QC density in

accordance with FM 1-T180. When compacting A -3 or A-2-4 materials to meet the alternate acceptance criteria in 145-6.3.1.1, determine the maximum density in accordance with FM 1- T099. Perform gradation tests on the sample collected in accordance with AASHTO T 27 and FM 1-T011. .

145-6.3Density Testing Requirements: Ensure compliance with the requirements of

nuclear density testing in accordance with FM 1-T238. Determine the in-place moisture content

for each density test. Use FM 5-507 (Determination of Moisture Content by Means of a Calcium

Carbide Gas Pressure Moisture Tester), or FM 5-535 (Laboratory Determination of Moisture

Content by Granular Soils by Use of a Microwave Oven) for moisture determination.

145-6.3.1 Acceptance Criteria: For select backfill, obtain a density in each LOT

of at least 95% of the maximum density as determined by FM 1-T180.

145-6.3.1.1 Optional Acceptance Criteria for A-3 and A-2-4 Materials:

Obtain a minimum density of 100% of the maximum dry density as determined by FM 1-T099.

The combined width from both reinforced fill volume and retained fill material may be

considered the same LOT if both volumes comprise the same material and both are compacted

with the same procedure, lift thickness, equipment and compacting effort.

145-6.4Frequency: Conduct sampling and testing at a minimum frequency listed in the

table below. The Engineer will perform verification sampling and tests at a minimum frequency

listed in the table below. 208FY 2023-24Return to Table of Contents

Table 145-2

Test Name Quality Control (QC) Verification

Maximum Density One per soil type One per soil type

Density One per LOT One per four LOTs

Soil Classification, Gradation,

LL & PI One per Maximum Density One per Maximum Density

Organic Content One per soil type One per soil type

In addition, test for pH at a minimum frequency of one test per soil type at point

of placement according to 145-3. The Engineer will collect enough material to split and create

two separate samples and retain one for resolution at point of placement until LOTs represented

by the samples are accepted.

145-6.5Test Selection and Reporting: Determine test locations including stations and

offsets, using the random number generator approved by the Engineer. Do not use notepads or

worksheets to record data for later transfer into the Earthwork Records System (ERS) section of

the Department’s database. Notify the Engineer upon successful completion of QC testing on

each LOT.

145-7Verification Comparison Criteria and Resolution Procedures

145-7.1Maximum Density Determination: The Engineer will collect enough material

to split and create two separate samples and retain one for resolution until LOTs represented by

the samples are accepted. The Engineer will meet the requirements of 120-10.4.1 except replace

FM 1-T099 with FM 1-T180. If the Contractor selects the optional acceptance criteria, the

Engineer will verify the QC results of FM 1-T099 in accordance with 120-10.4.1.

145-7.2Density Testing: Meet the requirements of 120-10.4.2

145-7.3Gradation: The Engineer will verify the QC results if the verification result

meets the gradation limits set forth in the gradation table of 145-3.2. Otherwise, the Engineer

will test the sample retained in 145-6.1. The State Materials Office (SMO) or an AASHTO

accredited laboratory designated by the SMO will perform resolution testing. The material will

be sampled and tested in accordance with AASHTO T 27 and FM 1-T011.

If the resolution test result satisfies the required gradation limits, the LOTs will be

verified. If the resolution test results do not meet the required gradation limits, reconstruct the

LOTs with acceptable material. The Engineer will perform new verification testing.

145-7.4Liquid Limit and Plasticity Index (LL&PI): The Engineer will verify the QC

results if the verification result satisfies the plasticity index and liquid limit criteria set forth in

548-2.6. Otherwise, the Engineer will test the sample retained in 145-6.1. The SMO or an

AASHTO accredited laboratory designated by the SMO will perform resolution testing. The

material will be sampled and tested in accordance with AASHTO T 90 and AASHTO T 89,

respectively.

If the resolution test result satisfies the required criteria, LOTs of that soil type

will be verified. If the resolution test results do not meet the required criteria, reconstruct the

corresponding LOTs with acceptable material. The Engineer will perform new verification

testing.

145-7.5Soil Classification: The Engineer will meet the requirements of 120-10.4.3

except test the sample retained in 145-6.1 instead of taking the additional one. 209FY 2023-24Return to Table of Contents

145-7.6Organic Content: The Engineer will verify the QC results if the verification

result satisfies the organic content test criteria set forth in 145-3.2. Otherwise, the Engineer will

collect three additional samples. The material will be sampled and tested in accordance with

FM 1-T267 and by averaging the test results for three randomly selected samples from at least

one lift per soil type. The SMO or an AASHTO accredited laboratory designated by the SMO

will perform resolution testing. If the resolution test result satisfies the required criteria, material

of that soil type will be verified and accepted. If the resolution test results do not meet the

required criteria, reject the material and reconstruct with acceptable material.

145-7.7pH: The Engineer will verify the QC results if the verification result satisfies the

pH test criteria set forth in 145-3.2. Otherwise the Engineer will collect an additional sample.

The SMO or an AASHTO accredited laboratory designated by the SMO will perform resolution

testing. The material will be sampled and tested in accordance with FM 5-550. If the resolution

test result satisfies the required criteria, material of that soil type will be verified and accepted. If

the resolution test results do not meet the required criteria, reject the material and reconstruct

with acceptable material.

145-8Method of Measurement

145-8.1Geosynthetic Reinforced Soil Slopes: The quantity to be paid for will be the

plan quantity area, in square feet, of the projected vertical height of the slope face, measured

from the top of slope to the finished graded surface at the toe of slope and from the beginning to

end limits as shown in the Plans, regardless of the length or number of layers of geosynthetic

within the reinforced volume and including any reinforcement required below the toe of slope

elevation.

145-8.2Geosynthetic Reinforced Foundations over Soft Soils: The quantity to be paid

for will be the plan quantity area, in square yards, of the embankment to be reinforced as shown

in the Plans, regardless of the length or number of layers of geosynthetic within the reinforced

soil volume, and including any reinforcement required below the original ground elevation.

145-9Basis of Payment

145-9.1Geosynthetic Reinforced Soil Slopes: Price and payment will be full

compensation for all work, materials, and services specified in this Section, including design and

shop drawings, geosynthetic materials, facing materials and/or treatment, installation, testing,

and required submittals. The cost and placement of all backfill material will be included in the

pay quantity for embankment or borrow excavation, as applicable.

145-9.2Geosynthetic Reinforced Foundations over Soft Soils: Price and payment will

be full compensation for all work, materials, and services specified in this Section, including

geosynthetic materials, geotextile filter materials, facing materials, drainage materials,

installation, testing, and required submittals. The cost and placement of all backfill will be

included in the pay quantity for embankment or borrow excavation, as applicable.

145-9.3Payment Items: Payment will be made under:

Item No. 145- 1- Geosynthetic Reinforced Soil Slopes - per square foot.

Item No. 145- 2- Geosynthetic Reinforced Foundations over Soft Soils - per

square yard. 210FY 2023-24Return to Table of Contents

STABILIZING

160-1Description

Stabilize designated portions of the roadbed to provide a firm and unyielding subgrade, having the required bearing value specified in the Plans.

160-2Materials

160-2.1Commercial Material: Meet the requirements of Section 914-2.1

160-2.2Local Material: Submit test results to the Engineer at least 14 days prior to the

stabilization operation. 160-2.2.1 Local Stabilizing Material: Sample and test material from each source and meet the requirements of Section 914. The Engineer will verify the Quality Control (QC) test results meet the requirements of Section 914. If the QC and Verification results do not compare, the Engineer will take one additional sample of material from the s ource in question and the State Materials Office (SMO) or an AASHTO accredited laboratory designated by the SMO will perform Resolution testing. If the Resolution test results satisfy the required criteria, material from that source will be verified and ac cepted. If the Resolution test results do not meet the required criteria, reject the material. 160-2.2.2 Reclaimed Asphalt Pavement (RAP) : Obtain the Engineer’s approval in writing for the option to use 100% RAP material . Material must be milled and stoc kpiled without blending or contaminating with any other material . 160-2.2.3 Reclaimed Asphalt Pavement (RAP ) Blended Material : RAP blended material is defined as material meeting the requirements of 914 -1 and 914 -2.2 except for the limits for organic content. If the RAP blended material meets the requirements of 914 -1 and 914-2, then the blended material will be classified as local stabilizing material . Provide test results to the Engineer and obtain their approval in writing before using RAP blended material. The Engineer will verify that the QC test results meet the acceptance criteria, otherwise the Engineer will perform Resolution testing procedures specified in 160 -2.2.1.

160-2.3Existing Base: Obtain the Engineer’s approval in writing before using existing

base. When the material from an existing base is used as all, or a portion, of the stabilizing additives, no further testing is required unless directed by the Engineer.

160-2.4Granular Subbase : The Engineer may allow, at no additional cost to the

Department, the substitution of 6 inches of granular subbase meeting the requirements of 290 -2 and 290-3, only when 12 inches of Type B stabilization requiring a Limerock Bearing Ratio

160-3Construction Methods

160-3.1General: Prior to the beginning of stabilizing operations, construct the area to be

stabilized to an elevation such that, upon completion of stabilizing operations, the completed stabilized subgrade will conform to the lines and grades shown in the Plans. Prior to spreading any additive stabilizing material, bring the surface of the r oadbed to a plane approximately parallel to the plane of the finished graded surface shown in the Plans. Construct mainline pavement lanes, turn lanes, ramps, parking lots, concrete box culverts, retaining wall systems, shoulder -only areas, sidewalk, and shared use path areas meeting the requirements of 120 -8.1, except replace “embankment” with “subgrade”. 211 FY 2023-24 Return to Table of Contents