205.01 174 SECTION 205 – EMBANKMENTS
205.01 Description ................................ ................................ ................... 174
205.02 Materials ................................ ................................ ...................... 174
205.03 Prepar ation of Embankment Areas ................................ .............. 174
205.04 Formation of Embankments ................................ ......................... 176
205.05 Stability of Embankments and Cut Slopes ................................ ... 179
205.06 Disposal of Excess or Unsuitable Material ................................ .. 180
205.07 Method of Measurement ................................ .............................. 180
205.08 Basis of Payment ................................ ................................ .......... 180
DESCRIPTION
205.01 Description
This work consists of constructing roadway embankments, including preparing the area upon which they are to be placed; constructing dikes within or outside the right -of-way; placing and compacting approved material wi thin roadway areas where unsuitable material has been removed; and placing and compacting embankment material in holes, pits, and other depressions within the roadway area. MATERIALS
205.02 Materials
For embankment and backfill, only use approved materi als, consisting of Road and Drainage Excavation, Channel Excavation, and Borrow Excavation material as specified in 203, or excess material as specified in 204. CONSTRUCTION REQUIREMENTS
205.03 Preparation of Embankment Areas
Before beginning embankment construction in any area, complete Clearing and Grubbing, Removal of Structures and Obstructions, and installation of preliminary erosion control measures according to the approved SWPPP as specified in 201, 202, and 209 respectively. 205.03 175 Address both natural and created steep slope areas as required in the TN Construction G eneral Permit. Maintain and stabilize steep slopes according to the TN Construction General Permit and all applicable environmental permits. Remove snow, ice, and mud before placing embankment materials on the ground. Do not place embankment materials on top of ground surfaces and existing embankment layers that are frozen. Fill all depressions or holes below the natural ground surface, whether caused by grubbing or otherwise, with suitable material and compact to the ground surface before starting embank ment construction. Unless otherwise shown on the Plans or specified in the Special Provisions, if constructing embankment of less than 3 feet below subgrade:
1.Remove all sod and vegetative matter from the surface.
2.Remove unsuitable material and repla ce with suitable material.
3.Break up the cleared surface by plowing, scarifying, or stripping to a minimum depth of 6 inches, and then re -compact this area.
4.If a compacted road surface containing granular materials lies within 3 feet of the subgrade, scarify the old road surface to a depth of at least 6 inches, and then re -compact the scarified material. Remove and dispose of concrete pavement, parking strip, and base, all with or without bituminous overlay, concrete curb and gutter, sidewalk , driveways, and similar features as specified in 202.06 or as otherwise directed by the Engineer. When placing embankment material on or against existing slopes that are steeper than 4:1, cut benches into the existing slope whil e bringing up the new embankment material in layers. Cut each bench of sufficient width to accommodate the operation of placing and compacting equipment. Begin each successive cut at the intersection of the original ground and the vertical side of the pr evious cut. Re -compact the cut material along with the new embankment material at no additional cost to the Department. Before placing embankment material on a structure or any unit of a structure, ensure that the surrounding backfill has been completed and thoroughly compacted to ground surface. 205.04 176 205.04 Formation of Embankments Do not incorporate or bury any perishable materials, such as brush, hedge, roots, stumps, and parts of trees, in the embankments. Do not place rock, broken concrete, or other solid objects in embankments areas where piling will be installed. Construct embankments to provide adequate surface drainage at all times. If roadway embankment materials consist predominantly of soil, place the material i n horizontal layers not to exceed 10 inches in loose thickness , and compact each layer to a density not less than 95% of maximum density. Unless otherwise specified, compact the top 6 inches of the road bed in both cut and fill sections to 100% of maximum density as specified in 207.04. The Department inspector conducting the density tests shall be a certified Nuclear Gauge Technician. The Engineer will determine maximum density and optimum moisture according to AASHTO T 99. For material with less than 5% retained on a No. 4 sieve, method A with 4 -inch mold will be used . For material with more than 5% retained on a No. 4 sieve but less than 50% retain ed on a 3/4-inch sieve, Method D with corrections according to AASHTO T 224 will be used . Use the correction on soils containing less than 50% plus 3/4-inch material. Determine the density of the soil in place according to an approved AASHTO method. Comp act each embankment layer to the required density, and obtain the Engineer’s approval before placing material for the next succeeding layer. Keep placing and compacting areas separate. When constructing embankment across low swampy ground that will not support earth moving equipment, construct the lower part of the fill in a uniformly distributed layer of a thickness not greater than necessary to support the hauling equipment while placing subsequent layers. Construct the embankment full width unless othe rwise shown on the Plans or approved by the Engineer. The Engineer will waive the density requirement for such a lift, but the moisture content of the material used shall not exceed the optimum moisture range for 95% density for that material. Comply wit h the maximum thickness and minimum density requirements for all succeeding layers of the embankment. When a minimum of 95% of maximum density is required, ensure that the moisture content of the material being compacted meets both of the following conditions: 205.04 177 1. The moisture content shall be within the range of values at which 95% of the maximum density can be obtained as indicated by the moisture-density relationship curve; and
2.The moisture content shall not exceed the optimum moisture content to the extent that the material pumps under loads applied by the construction equipment. Even if the required density is achieved and the moisture content is in range, if pumping occurs, remove the affected sections. When 100% of maximum density is required , the moisture content of the material being compacted shall meet condition (2) above and shall not vary from the optimum moisture content by more than plus or minus 3%. Aerate the material, or distribute and incorporate water uniformly into the material, as necessary, to control the moisture content within the applicable limits. If the excavated material consists predominantly of rock, the following shall apply:
A.Definition of Material If deemed necessary by the Engineer, the Contractor shall conduct test or tests with a 60,000 -pound static tamping foot roller (costs to be included in other items) to determine whether the material is degradable or non-degradable. Consider material that readily breaks down under three passes of the 60,000 -pound static tamp ing foot roller as degradable.
B.Non-Degradable Rock If sound, non -degradable rock is encountered in the unclassified excavation, the Engineer may require the Contractor to provide a mechanical means for separating the sound rock from degradable rock and other soils. The Engineer may allow the use of sound, non - degradable rock in the backfilling of benches, lower and outside portions of embankments, rock buttresses, or other areas. If the material for embankments consists of sound, non -degradable rock of a size that makes placing the material in 10 -inch layers impracticable , place the material in layers no thicker than 3 feet. Do not use rock fragments greater than 2 feet in maximum dimension. With the 205.04 178 Engineer’s approval, the Contractor may place occas ional individual rocks and boulders not exceeding 4 feet in height in the exterior portions of the embankment next to the slope face. Place such rocks to prevent nesting and fill the adjacent voids with fine fragments to form a dense and compact mass. Do not dump rock material into its final position. Place rock by blading or dozing in a manner that will minimize voids, pockets, and bridging. Ensure that each layer is leveled the full width of the embankment. Rolling is not required if the rock embankm ent consists of sound, non - degradable material placed in greater than 10 -inch layers.
C.Degradable Rock Compact degradable rock for use in embankment with an approved vibratory tamping -foot roller in conjunction with a static tamping -foot roller. The minimu m weight for the static tamping -foot roller shall be 60,000 pounds. The minimum compaction effort, as rated by the manufacturer, for the vibratory tamping -foot roller shall be 55,000 pounds. Submit roller specifications to the Engineer for approval before use. Place degradable rock in 10 -inch maximum loose lifts and provide a minimum of three passes with the static roller and two passes with the vibratory roller. The Engineer may direct additional passes with either or both rollers until satisfactory breakdown and compaction is accomplished. Do not place degradable rock in the top 5 feet of an embankment unless approved by the E ngineer. If embankment composed of degradable rock does not contain sufficient moisture to compact properly, the Engineer will require the Contractor to apply water in sufficient quantities to achieve the approximate optimum moisture for the particular mat erial involved. Uniformly mix the added water with the material for the entire depth of the lift by blading, discing, or other approved methods.
D.Combination of Degradable and Non -Degradable Rock Do not blend or combine degradable rock and non -degradable r ock in a common lift without the Engineer’s written approval. If approved, place embankment material consisting of a mixture of degradable rock and non -degradable rock, or rock and soil, in layers not 205.05 179 exceeding 10 inches in thickness unless otherwise direc ted by the Engineer. If the combined material is predominantly sound, non - degradable rock with fragments thicker than 10 inches, the Engineer may increase the layer thickness to be consistent with the size of the material, not to exceed 3 feet. Place the mixture by blading or dozing in a manner that will minimize voids, pockets, and bridging. Compact the mixture with suitable compaction equipment as defined in 205.04.A, and apply water to facilitate compaction as directed by the Engineer. Uniformly mix the added water with the material for the entire depth of the lift by blading, discing, or other approved methods.
E.Density Requirements Density requirements will not apply to portions of embankments constructed of materials that cannot be tested by approved methods. When the Plans require Solid Rock Fill , the material shall meet the quality requirements in 903.25. Do not use plastic soil or shale material. Place Solid Rock Fill as shown on the Plans or as directed by the Engineer. Construct the roadway through rock fills to the grading line shown on the Plans with an allowable working tolerance of plus 1 to minus 3 inches. Bring up to grade those portions of the roadway that are then below grade with spalls or oth er suitable granular material that is available from the excavation within the balance. If no such excavation is available, the Engineer may direct the Contractor to use approved base material for bringing the fill to grade, not to exceed the specified 3 -inch limit. If embankment material is to be placed on both sides of a concrete wall or box type structure, bring the material up equally on both sides of the structure. At the location of abutments, bents, and similar features , construct embankment to the finished grade before starting excavation on the respective section of the substructure, unless otherwise shown on the Plans. If embankment material is to be placed on only one side of abutments, wing walls, piers, and similar features , do not beg in construction until the superstructure is in place. Perform compaction operations without causing wedge action or placing excessive pressure against the structure.
205.05 Stability of Embankments and Cut Slopes
Assume responsibility for the stability of all embankments and cut slopes until final acceptance. In accordance with 105.16 and as determined by the 205.06 180 Engineer, r eplace or rework all portions that have become displaced or damaged at no additional cost to the Department.
205.06 Disposal of Excess or Unsuitable Material
Dispose of excess or unsuitable material as specified in 203.07. COMPENSATION
205.07 Method of Measurement
The Department will not measure embankment. The Contractor shall construct embankments under the items described in 203 and 204 that apply to the materials used to construct the embankments. The Department will measur e excavation to bench side -hill slopes for embankment construction in accordance with 203.09.A.2 .
205.08 Basis of Payment
The Department will not directly pay for embankments. The contract unit prices for the materials wi th which embankments are acceptably constructed is full compensation for all embankment construction, including materials, equipment, labor, and incidentals to complete the work as specified. If the Contractor encounters pumping of soil despite having achi eved the required density and moisture content, the Department will pay for the removal of these sections as Undercutting by the cubic yard in cut sections only. No such payment will be made in fill sections. If the excavated material consists predominant ly of rock, the Department will pay for water required and provided by the Contractor to facilitate compaction at the unit price per M.G. (1,000 gallons ) for Water, which price is full compensation for furnishing and applying the water, mixing, labor, and equipment. The Department will consider all other costs associated with the constructing embankment of material consisting predominantly of rock, including providing suitable compaction equipment and separating sound rock from degradable rock and soils, a s included in the unit price for Road and Drainage Excavation (Unclassified). If the Engineer directs the Contractor to use approved base material to bring portions of the roadway that are less than 3 inches below grade up to grade, 205.08 181 the Department will mea sure and pay for the furnishing and placing of such base material in tons under the applicable item in 303.15. If base material is not a bid item in the Contract, the Contractor shall provide the material under the provisions of 104.02.D. If, despite proper construction and protection, damage to the embankments or cut slopes occur s due to unusual natural causes such as cloudbursts, floods, slides or subsidence, the Department will pay for the material used to make the necessary repairs at the contract unit price for the material classification designated by the Engineer to be used for this purpose. The Department will pay for removal of slides in accordance with 203.10. 206.01 182 SECTION 206 – FINAL DRESSING
206.01 Description ................................ ................................ ................... 182
206.02 Reserved ................................ ................................ ....................... 182
206.03 Method and Scope of Work ................................ ......................... 182
DESCRIPTION
206.01 Description
This work consists of dressing all slopes and areas, including borrow pits and embankments, and generally preparing the Project for final i nspection and acceptance. The costs of this work are incidental to other items of construction.
206.02 Reserved
CONSTRUCTION REQUIREMENTS
206.03 Method and Scope of Work
Perform final dressing by hand work and machines to produce a uniform satisfactory finish to all parts of the roadway and other components of the Project. Shape the roadbed, shoulders, ditches , and slopes to within reasonably close conformity to the spe cified lines, grades, and cross -sections. Dress spoil banks, borrow areas, waste are as, and similar areas. Clear rock cuts of all loose fragments, and leave in a neat, safe, and workmanlike condition. Clean the right -of-way of all weeds, briars, and brushes unless otherwise shown on the Plans. Clear and clean all structures, both old an d new, of all brush, drifts, heavy vegetation, sediment, rubbish, obstructions, and other objectionable material. Perform final dressing before sodding and seeding operations if the Contract includes these construction items. Run tracked machines used in d ressing slopes up and down slopes as opposed to longitudinally.
Source: Tennessee Standard Specifications for Road and Bridge Construction, 2021 Edition. Pages 183–190 of 1,072.