Embankment Art. 205.02 the difference between the existing ground line shown on the plans and the new ground line established from the settlement platforms.
b.Measured Quantities. Furnished excavation will be computed for payment in cubic yards (cubic meters) as follows. Furnished Ex. = Embankment - [Excavation x (1 - Shrinkage Factor)] Where: Embankment = the volume of fill in its final position computed by the method of average end areas and based upon the existing ground line as shown on the plans, except as noted in (1) and (2) below; Excavation = suitable and/or restricted-use excavation such as earth excavation, rock excavation, and other on-site excavation acceptable for use in embankments as shown in the Earthwork Schedule on the plans; Shrinkage Factor = 0.25 unless otherwise shown on the plans.
1.If the Contractor so requests, the Engineer will reestablish the existing ground line after the clearing and tree removal have been performed according to Section 201 and the top 6 in. (150 mm) of the existing ground surface has been disked and compacted.
2.If settlement platforms are erected, the Engineer will reestablish the existing ground line after the embankment is complete as specified in
Article 204 — 07(a)(2).
The quantity for furnished excavation will not be recalculated when surplus, suitable or restricted-use materials are utilized in embankments according to
Article 202 — 03.
204.08 Basis of Payment. Borrow and furnished excavation will be paid for
at the contract unit prices per cubic yard (cubic meter) for BORROW EXCAVATION and FURNISHED EXCAVATION. SECTION 205. EMBANKMENT
205.01 Description. This work shall consist of the construction of
embankments by depositing, placing, and compacting earth, stone, gravel, sand, or other materials of acceptable quality above the existing ground or other surface.
205.02 Equipment. Equipment shall be according to the following.
Item Article/Section
a.Disk Harrow ....................................................................................... 1101.02 Art. 205.03 Embankment CONSTRUCTION REQUIREMENTS
205.03 Preparation of Existing Ground Surface. Before any embankment
is placed, all clearing and tree removal over the entire roadway area shall be performed according to Section 201, and the top 6 in. (150 mm) of the existing ground surface shall be disked and then compacted. Snow and ice shall be removed from the area to be covered by the embankment. Embankment shall not be placed on frozen earth. If suitable soil at the existing ground surface is unstable according to
Article 1009 — 04, it shall be rendered stable or declared unsuitable by the Engineer
according to Article 202.05. If soil at the existing ground surface exhibits the potential for significant erosion or excessive volume change it may also be declared unsuitable at the discretion of the Engineer. Material declared unsuitable shall be removed and disposed of according to Article 202.03, and replaced with additional material approved by the Engineer according to Articles 205.04 and 205.05. Ditches shall be cut for ground preparation and/or to aid in rendering existing soils stable as directed by the Engineer. When sand, gravel, or crushed stone is placed on the existing ground surface it shall be drained as directed by the Engineer. When construction is resumed after a winter shutdown period, the top 8 in. (200 mm) of partially completed embankments shall be disked and compacted to the minimum specified density according to Article 205.06 prior to placing more fill material on the embankment. When embankments are to be constructed on hillsides or slopes, or if existing embankments are to be widened or included in new embankments, the existing slopes shall be plowed deeply. When hillsides, slopes, or existing embankments are equal to or steeper than 1:3 (V:H), steps shall be keyed into the existing slopes by stepping and benching before construction of the embankment is started as detailed in the plans or as directed by the Engineer. When embankments are to be constructed over an existing pavement, the following shall govern.
a.Aggregate Surfaces and Bituminous Surface Treatments over Aggregate Bases. When the surface of the pavement is within 6 in. (150 mm) of the elevation of the subgrade, it shall be plowed, disked, or otherwise broken up to a depth of not less than 6 in. (150 mm).
b.Hot-Mix Asphalt Base Courses, Surfaces, and Pavements; and Portland Cement Concrete Base Courses and Pavements.
1.When the distance between the existing pavement and the proposed bottom of subgrade is greater than 3 ft (1 m), the existing pavement shall stay in place.
2.When the distance between the existing pavement and the proposed bottom of subgrade is 3 in. (75 mm) to 3 ft (1 m), the existing pavement Embankment Art. 205.04 shall be broken into pieces where each piece is no greater than 3 sq ft (0.3 sq m) in surface area. At the option of the Contractor, the broken roadway may stay in place unless otherwise directed by the Engineer.
3.When the distance between the existing pavement and the proposed bottom of subgrade is less than 3 in. (75 mm), the existing pavement shall be removed.
205.04 Placing Material. Embankments shall be constructed of materials that
will compact and develop stability. No sod, frozen material, or any material which, by decay or otherwise, might cause settlement shall be placed or allowed to remain in embankments within the area of the roadbed. Embankments shall be constructed to the height and width deemed necessary to provide for shrinkage during compaction. Upon completion, the embankments shall be according to the lines, grades, and cross sections shown on the plans. So far as practicable, each lift of suitable material according to Article 1009.04 shall extend the entire length and width of the embankment. The material shall be leveled by means of bulldozers, blade graders or other equipment approved by the Engineer. Restricted-use materials according to Article 1009.04 may be used but shall be limited to the interior of a constructed embankment. Restricted-use materials shall be encapsulated by suitable soil a minimum of 2 ft (600 mm), measured vertically and horizontally from each face of the in-place restricted-use materials. The existing ground line may serve as the lower horizontal/vertical boundary for restricted-use materials. Each lift of suitable or restricted-use material shall not exceed 8 in. (200 mm) thick when in loose condition, and shall be uniform in cross section, disked, and thoroughly compacted according to Article 205.06 before the next lift is started. Restricted-use miscellaneous materials shall be well distributed with suitable and/or restricted-use finer material incorporated within each lift such that the interstices are completely filled and provide a solid embankment lift. Pieces of concrete not exceeding 2 sq ft (0.2 sq m) for any surface area, large rocks and boulders, and other similar restricted-use miscellaneous materials may be placed in embankments fills without being broken up, provided they are well embedded, and the interstices filled with smaller pieces or smaller suitable or restricted-use material in a manner to provide a density satisfactory to the Engineer. The lifts of the smaller pieces or smaller material shall not exceed 12 in. (300 mm) in depth. Shale shall be placed, broken down, and compacted in the same manner as soil. The addition of water may be required to break the shale down. When sand, gravel, or crushed stone is placed on top of cohesive embankment material or when recycled asphalt pavement is utilized in the embankment, permanent subsurface drainage facilities shall be provided to prevent water from collecting within the embankment as required by the Engineer. This may include shaping of the cohesive embankment material to allow water to drain to a perforated pipe, placement of perforated pipes with a maximum diameter of 6 in. (150 mm) in Art. 205.04 Embankment either the longitudinal or transverse directions, or other features. If transverse pipes are used, they shall be placed at sag vertical curves and no more than 500 ft (150 m) apart. If longitudinal pipes are used, they shall be placed on the low sides of the roadway crown. All pipes shall be sloped to provide drainage and be equipped with headwalls. Suitable and restricted-use soils that are unstable according to Article 1009.04 shall be rendered stable or declared unsuitable by the Engineer according to
Article 202 — 05. If a soil exhibits the potential for significant erosion or excessive
volume change it may also be declared unsuitable at the discretion of the Engineer. Material declared unsuitable shall be removed and disposed of according to
Article 202 — 03 and replaced with a material approved by the Engineer.
The use of drag line excavators or similar equipment which excavate and deposit material in large unit masses will not be permitted, unless all materials excavated in this manner are spread as provided herein and compacted according to
Article 205 — 06, or as directed by the Engineer.
205.05 Placing Material Adjacent to Structures. When bridges and culverts
are not completed in advance of grading operations, an omission in the embankment of not less than 100 ft (30 m) on each side of each structure shall be made, until such omitted embankment shall be placed later according to the requirements of these Specifications. As an alternate method, an omission in the embankment of sufficient length to permit the completion of the structure and the necessary backfills may be made, provided all backfills and omitted embankments are constructed with granular material furnished and placed at no additional cost to the Department. The granular material shall be according to Article 1004.05, and shall be compacted according to
Article 205 — 06.
Embankment behind abutments or around structures shall not be constructed until field cured test specimens show that the concrete has attained a flexural strength of 650 psi (4,500 kPa) or a compressive strength of 3,500 psi (24,000 kPa). In the absence of strength tests, the minimum length of time between the completion of the abutment or structure and the placing of the embankment shall be at least 14 days exclusive of days in which the temperature falls below 45 °F (7 °C). Embankment, behind abutments held at the top by the superstructure, shall not be placed until the superstructure has been completed and the false work removed. Embankment, behind such abutments and behind the walls of culverts having a clear height of more than 5 ft (1.5 m), shall be carried up simultaneously at both ends of the structure, and at no time shall the embankment at one end be more than 2 ft (600 mm) higher than at the other. Backfill shall not be placed in water at closed abutments, culverts or retaining walls. The excavated area around these structures shall be pumped dry, and any mud or loose material within the excavated space shall be removed. Sloping sides of the excavated space, that would be liable to cause objectionable wedging action of the backfill against the structure, shall be stepped or serrated to prevent such action. At piers, backfill may be placed in water, provided that both the water level and backfill are kept at approximately the same elevation on opposite sides of the pier. A time interval, approved by the Engineer, shall elapse before placing additional fill on one side of the pier above the water surface. Embankment Art. 205.06 When drain holes are present in abutments, wingwalls, retaining walls, or culverts, a 24 in. (600 mm) wide x 48 in. (1.2 m) tall strip of geocomposite wall drain material, according to Article 1040.07, shall be placed on the soil side of each drain hole. The strip shall be horizontally centered over the drain hole with the bottom located 12 in. (300 mm) below the bottom of the drain hole.
205.06 Compaction and Stability. Each lift of the embankment material shall
be disked sufficiently to break down oversized clods, mix the different materials, secure a uniform moisture content, and ensure uniform density and compaction. Disking may be omitted if the fill material consists of sand, gravel, or crushed stone. The moisture content of all embankment lifts shall be a minimum of 80 percent of the optimum moisture content and shall not exceed 110 percent of the optimum moisture when determined according to Illinois Modified AASHTO T 99 (Method C) using a coarse particle correction (Annex A1). The Contractor will be permitted the use of an approved additive to affect a quicker drying time for borrow and furnished excavation materials. When approved by the Engineer, the maximum optimum moisture content may be waived for free draining granular material. The embankment shall be sprinkled with water when it is necessary to increase the moisture content of the soil. The dry density of the compacted embankment will be determined by the Engineer at regular intervals according to Illinois Modified AASHTO T 191, Illinois Modified AASHTO T 310 (Direct Transmission Density/Backscatter Moisture), or by other methods approved by the Engineer. Compacting equipment and compacting operations shall be coordinated with the rate of placing embankment so that the required density is obtained. If the roadway embankment is less than 1 1/2 ft (450 mm) in height, all lifts shall be compacted to not less than 95 percent of the standard laboratory dry density determined according to Illinois Modified AASHTO T 99 (Method C) using a coarse particle correction (Annex A1). In addition, each lift shall have a minimum immediate bearing value (IBV) of 4.0 according to ITP 501 or ITP 502. If the embankment is 1 1/2 ft to 3 ft (450 mm and 900 mm) in height, the first lift shall be compacted to not less than 90 percent, and the balance to a minimum of 95 percent of the standard laboratory dry density with a minimum IBV of 4.0. If the embankment exceeds 3 ft (900 mm) in height, the lower 1/3 of the embankment, but not to exceed the lower 2 ft (600 mm), shall be compacted in a manner that will yield a minimum of 90 percent of the standard laboratory dry density to the uppermost lift of that portion of the embankment. The next 1 ft (300 mm) of embankment shall be compacted to not less than 93 percent, and the balance of the embankment compacted to not less than 95 percent of the standard laboratory dry density with a minimum IBV of 4.0. Embankment lifts not meeting the foregoing criteria will be declared unstable by the Engineer. These lifts shall be rendered stable through reprocessing and recompacting. As determined by the Engineer, material from unstable lifts that cannot be rendered stable may be declared unsuitable. Material declared unsuitable by the Engineer, shall be removed and disposed of according to Article 202.03, and replaced with material approved by the Engineer according to Articles 205.04 and 205.05. Art. 205.07 Granular Embankment, Special Special care shall be exercised in compacting embankments adjacent to structures and in sharp depressions. Where such areas are inaccessible to the compacting equipment being used, the material shall be placed in 8 in. (200 mm) horizontal lifts and uniformly compacted with suitable mechanical equipment.
205.07 Maintaining and Trimming Embankments. The Contractor shall
replace any portions of the embankment which have been damaged or displaced by reason of carelessness or negligence on the Contractor’s part. After the embankments have been constructed, their sides shall be trimmed to the proper slopes where required, and shall be maintained by the Contractor to the proper elevation and cross section until acceptance.
205.08 Method of Measurement. Embankment will not be measured for
payment. Mechanical compaction will not be measured for payment.
205.09 Basis of Payment. Embankment, permanent drainage features and
facilities, and any additive or water applied will not be paid for directly but shall be considered as included in the various items of excavation, and their construction shall be included in the unit prices for these items. Excavation and replacement of material declared unsuitable by the Engineer will be classified and paid for according to Article 109.04 SECTION 206. GRANULAR EMBANKMENT, SPECIAL
206.01 Description. This work shall consist of the construction of granular
embankment by placing and compacting gravel or crushed stone on an existing pavement or surface course.
206.02 Materials. Materials shall be according to the following.
Item Article/Section
a.Coarse Aggregate (Note 1) ................................................................ 1004.04 Note 1. The aggregate shall have a bearing ratio of not less than 80. For crushed gravel, crushed stone, and crushed slag, the bearing ratio requirement shall not apply. The bearing ratio will be determined according to the Standard Methods adopted by the Department.
206.03 Equipment. Equipment shall be according to the following.
Item Article/Section
a.Tamping Roller .................................................................................. 1101.01
b.Pneumatic-Tired Roller ...................................................................... 1101.01
c.Three-Wheel Roller (Note 1) .............................................................. 1101.01
d.Tandem Roller (Note 1) ..................................................................... 1101.01
e.Vibratory Machine (Note 2)
Referenced in this section
EMBANKMENT in other states
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Source: Illinois Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 104–109 of 1,217. View official source ↗