529.02 Materials.
524.05 Basis of Payment.
a.Unit Price Coverage . The contract price for Culvert Concrete and Culvert Concrete Extension shall be full compensation for all labor, tools, equipment, and incidentals necessary to construct the complete culvert and related structures (toe walls, wing walls, parapets, connections to draina ge structures, etc.). The contract price shall also be full compensation for design and submittals, construction of cofferdams, temporary diversion channels, protection of water quality at cofferdams and diversion channels, flood protection and falsework a nd formwork. Payment will not be separated for individual culverts.
b.Payment will be made under Item No .: 524-A Culvert Concrete ( * ) - per cubic yard {cubic meter} 524-B Culvert Concrete Extension ( * ) - per cubic yard {cubic meter} * Enter either Cast In Place or Precast if the type of construction must be designated. RETAINING WALL
529.01 Description.
Retaining walls shall be constructed at the locations and within the limits shown on the plans. Standard det ails may be shown on the plans for the construction of cast -in-place reinforced concrete retaining walls. The details for the construction of other types of retaining walls may also be shown on the plans. The submittal and approval of the design and detai ls of a retaining wall is required if the details of the retaining wall are not shown on the plans.
529.02 Materials.
a.Selected Backfill Material . Selected backfill material for Mechanically Stabilized Earth (MSE) Walls and Gravity Walls shall be well g raded, angular, commercially produced sand or crushed stone (material containing slag will not be allowed) free from organic matter and/or other deleterious material. The following types of materials will be allowed: • Concrete sand meeting the requirements of Section 802, Fine Aggregates (F.M. waived). • Section 801 Coarse Aggregate crushed material that is smaller than #467 with 10% or less passing the #200 {75 µm} sieve. • Crusher run material with 100% passing a 2 -inch {50 mm} sieve and with 10% or less passi ng the #200 {75 µm} sieve.
b.Cast-in-Place Reinforced Concrete Retaining Wall . Concrete for cast -in-place reinforced concrete retaining walls shall be Class A concrete in accordance with the material requirements given in Section 501. Reinforcing steel shall be furnished and placed in accordance with the material requirements given in Section 502. The bituminous expansion joint filler and waterstop shall meet the requir ements given in Section 832. Dowels at expansion joints shall be plain Grade 60 bars meeting the requirements given in AASHTO M 31. Pipe sleeves at expansion joints shall be Grade 36 sleeves meeting the requirements given in AASHTO M 270. Cast-in-place wal ls shall have a deposit (belt), not less than 1 foot {300 mm} wide and 1 foot {300 mm} deep, of approved local or commercial free draining material placed full length along the back face of the vertical walls at the line of weepholes. This material shall c onform to the requirements given in Subarticle 214.02(b).
c.Mechanically Stabilized Earth Retaining Wall . Approved ALDOT MSE wall systems are shown in the "Material, Sources and Devices with Special Acceptance Requirements" manual, List II -22, "MSE Wall Systems". The materials required for a mechanically stabilized earth retaining wall shall meet the requirements of the approved MSE wall system. The material and construction requirements shall be shown on the details of the wall submitted
529.03 Construction Requirements.
by the Contractor. The details of the wall will be distributed by the Engineer for inspection of the installation of the wal l.
d.Gravity Wall . Approved ALDOT gravity wall systems are shown in the "Material, Sources and Devices with Special Acceptance Requirements" manual, List II -28, "Gravity Wall Systems". The materials required for a gravity wall shall meet the requireme nts of the approved gravity wall system. The material and construction requirements shall be shown on the details of the wall submitted by the Contractor. The details of the wall will be distributed by the Engineer for inspection of the installation of the wall.
e.Precast Concrete Wall Components and Masonry Wall Facing Elements . All precast and masonry concrete items shall meet the requirements given in Section 831. All precast and masonry concrete items shall meet the material requirements established by the ALDOT through the submittal and approval of wall designs, material requirements and details.
529.03 Construction Requirements.
a.Contractor's Option to Select the Type of Retaining Wall . The Contractor shall have the following four options for the construction of a retaining wall if the required type of wall is not shown on the plans: • ALDOT designed cast -in-place reinforced concrete retaining wall; • Contractor designed cast -in-place reinforced concrete retaining wall; • reinforced mechanically stabilized earth (MSE) retaining wall; • gravity wall. MSE and gravity walls shall be designed and fabricated by, or under the technical supervision of an ALDOT approved supplier. Approved ALDOT MSE walls systems are shown in the "Material, Sources and Devices with Special Acceptance Requirements" manual, List II -22, “MSE Wall Systems” . Approved ALDOT gravity walls systems are shown in List II -28, "Gravity Wall Systems" . Information concerning these lists is given in Subarticle 106.01(f) and ALDOT -355.
b.Contractor Qualifications . The Contractor shall submit descriptions of the retaining wall projects completed in the last three years to serve as evidence of the capability to construct the chosen wall system. The descriptions of the retaining wall projects shal l contain names and telephone numbers of owners’ representatives who can verify the Contractor’s participation on those projects. These descriptions shall be submitted with the "wall installation plan" and will be evaluated by the Engineer.
c.Requirement for the submittal of Retaining Wall Designs, Details, and Installation Plan . The submittal of the design and details of a retaining wall is required if the details of the retaining wall are not shown on the plans. The Contractor shall submit 8 copies of the complete details, material requirements and design calculations to the Engineer for review no later than 30 calendar days after the date of the Notice to Proceed. The contractor shall also submit a Wall Installation Plan that includes: • name and experi ence record of the superintendent in charge of the retaining wall installation; • list of proposed equipment to be used; • details of the proposed sequence of retaining wall construction; • details of planned excavation and shoring methods, if shoring is required; • details of earth reinforcement placement including methods proposed to prevent damage to the reinforcement during subsequent backfill placement. The design calculations shall i nclude an analysis of the internal and external stability of the wall and all structural connection details of the wall. All proposed details, material requirements and design calculations shall be stamped and signed by a Licensed Professional Engineer li censed in the state of Alabama and not employed by ALDOT. The design shall be in conformance with the requirements given in the current AASHTO Standard Specifications for Highway Bridges as amended by interim revisions. The Engineer will review the retaini ng wall installation plan, wall design details, materials requirements, and design calculations for conformance with the plans and specifications. The Engineer will not approve the submittal but will review it to make sure that it is sufficiently complete to allow the construction of the wall. The Engineer will return the submittal for corrections, distribute the submittal for construction inspection, or contact the Contractor to establish a mutually agreeable date and time for a meeting to
529.04 Method of Measurement.
discuss the su bmittal. The Contractor will be notified of changes in the submittal deemed necessary within seven days after the meeting. Retaining wall construction shall not begin until the submittal has been distributed for construction inspection and the Engineer i nforms the Contractor in writing that the proposed wall details, material requirements, design calculations and wall installation plan are complete. Distribution of the submittal for construction inspection shall not relieve the Contractor of the responsibility to satisfactorily complete the work as detailed on the plans and in the specifications. Any proposed modification of the installation plan during construction shall be submitted to the Construction Engineer for review and distribution.
d.Excavation . The Contractor shall perform the excavation in a manner that will prevent damage to adjacent structures and maintain the stability of the ground adjacent to the excavation. Excavated material that remains after the construction of the wall shall be used in the formation of the embankment, roadbed, base layers, shoulders, slopes, bedding, backfill for culverts, and for other purposes as allowed or directed by the Engineer. The material shall be suitable for the use that is allowed or directed by the Engin eer. Excavated material that cannot be used as a part of the construction in other areas of the project shall be disposed of in accordance with the requirements given in Section 210 for the disposal of surplus material.
e.Cast-in-Place Reinforced Concrete Retaining Wall . ALDOT designed Cast -In-Place Walls shall be constructed in accordance with the details shown on Sheets 1 through 4, in ALDOT Standard Drawing RW 10 -4. Concrete for cast -in-place reinforced concrete retaining walls shall be furnished and placed in accordance with the requirements given in Section 501. Reinforcing steel shall be furnished and placed in accordance with the material and construction requirements given in Section 502. All other materials shall be installed in accordance wi th the details shown on the standard wall details or the approved wall details.
f.Mechanically Stabilized Earth (MSE) Retaining Wall . The Contractor shall construct the mechanically stabilized earth (MSE) retaining wall in accordance with the details sho wn on the Contractor's submittal of the MSE wall that is distributed by the Engineer.
g.Gravity Wall . The Contractor shall construct the gravity wall in accordance with the details shown on the Contractor's submittal of the gravity wall that is distribut ed by the Engineer.
h.Drainage Layer . A drainage layer of backfill is required where there are weepholes. The drainage layer shall be free draining material placed full length along the back face of the walls at the line of weepholes. The drainage layer shall not be less than 1 foot {300 mm} wide and 1 foot {300 mm} deep.
i.Final Finish on the face of MSE and Gravity Walls. Unless shown otherwise on the plans, MSE and gravity walls shall be built using the concrete finish provided by the manufacturer.
529.04 Method of Measurement.
Compensation for retaining walls will be made for the number of square feet {square meters} within the limits of payment shown on the plans. (The Engineer will not conduct field measurements of the wall for the purposes of pa yment, other than for Partial Payments under Article 109.07.) The limits of payment will be the following: • top of the wall; • bottom of the wall (bottom of leveling pad or footing where the bearing capacity is shown); • beginning and end of the wall. The limit s for payment shown on the plans will not be altered unless directed by the Engineer in writing. All portions of the wall, except barrier rails, constructed outside the limits for payment shown on the plans will be considered integral and subsidiary to the construction of the wall and will not be measured for payment. Reinforced concrete barrier rails at the top of the wall will be measured and paid for under other items of work. All other items of work, including but not limited to selected backfill material for all components of the wall, the furnishing and installation/construction of all footings/leveling pads, copings, caps,
529.05 Basis of Payment.
reinforcing strips, reinforcing mesh, permanent and temporary facing shall be included in the contract price for t he retaining wall and will not be measured separately for payment. The cost of all excavation within 4 feet {1.3 m} of the front face (top of wall to bottom of footing) of the wall and all excavation behind the wall shall be included in the square foot con tract price for the wall. Separate payment will not be made for the use or disposal of the excavated material that remains after the completion of the construction of the wall. Excavation beyond 4 feet {1.3 m} from the front face of the wall that is requ ired for roadway construction will be paid for under other items of work.
529.05 Basis of Payment.
a.Unit Price Coverage . The retaining wall will be paid for at the contract unit price per square foot {square meter} which shall be full compensation for all required designs and submittals and for furnishing all materials, fabrication, erection, construction, excavation, utilization and disposal of surplus excavated material, furnishing and placing selected backfill material, equipment, tools, labor, and i ncidentals necessary to complete this item of work.
b.Payment will be made under Item No .: 529-A Retaining Wall * - per square foot {square meter} * Retaining Wall Identification and Supplemental Description , if required. (i.e. Number 1, Number 2, MSE Wall Number 3, etc.) SECTION 530 ROADWAY PIPE CULVERTS
530.01 Description.
This Section shall cover the work of furnishing and installing pipe type culverts of the size, shape, wall thickness, type material, and appropriate strength designated on the plans or in the proposal. The installation shall be at the locations shown on the plans or designated in conformity with the lines and grades shown by the plans or designated by the Engin eer. The work shall include the furnishing and construction of such joints, cuttings, and connections to other pipes or structures as may be necessary to complete the work as shown on the plans or directed. This Section shall also cover the work of furnish ing and installing pipe culverts by the jacking (boring) method of construction. Unless specifically authorized in writing by the Engineer, jacking (boring) shall be used only at the locations shown on the plans. This type of pipe installation will be paid for under Pay Item 530 -C. The following abbreviations will be used: Concrete Pipe
P.C. for plain concrete
R.C. for reinforced concrete Corrugated Metal C.M. for any acceptable corrugated metal pipe covered by these specifications Protective Coating C. for any protective coating of metal pipe allowed by these specifications Paved Invert P.I. Corrugated Steel C.S. for Plain Corrugated Steel
C.C.S. for Coated Corrugated Steel
C.C.S.P.I. for Coated C.S. Paved Invert Corrugated Aluminum C.A. f or Plain Corrugated Aluminum
C.C.A. for Coated C.A.
C.C.A.P.I. for Coated C.A. Paved Invert Concrete Lined C.L. Unless a specific type of pipe is designated by the plans or proposal, the Contractor may use one of the optional types of pipe shown by the plans or proposal. However, an installation, once started, shall be made with the same type of pipe throughout unless specifically designated otherwise by plan details, or directed in writing. The Contractor, at his option, may furnish a stronger grade pipe than specified provided no additional cost is incurred by the State for such installation. The Contractor shall also have the option to use Horizontal Elliptical (H.E.) Pipe in lieu of Concrete Arch Pipe provided the H.E. pipe equals or exceeds the A rch pipe in strength and equivalent opening. If
Source: Alabama Standard Specifications for Highway Construction, 2022 Edition. Pages 402–404 of 934.