division 200 specifications: earthwork · 2. the contractor has requested to begin borrow...
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Division 200
Specifications: EarthworkOverview of Major Revisions
MICHELLE R. MANN, P.E.
[email protected] (505) 490-1507
NMDOT GEOTECHNICAL ENGINEERING/EXPLORATION SECTION MANAGER
Division 200 Specifications2014 Specification 2019 Specification Modifications
201: Clearing and Grubbing 201: Clearing and Grubbing Minor Revisions
203: Excavation and Borrow 203: Excavation and Borrow Major Revisions
- 203-A Unstable Subgrade Stabilization Newly added
206: Excavation and Backfill for
Culverts and Minor Structures
206: Excavation and Backfill for Culverts and
Minor StructuresMajor Revisions
207: Subgrade Preparation 207: Subgrade Preparation Minor Revisions
208: Linear Grading Deleted Due to overlap with Section
209
209: Blading and Reshaping 209: Blading and Reshaping Minor Revisions
210: Excavation and Backfill for Major
Structures
210: Excavation and Backfill for Major
StructuresMajor Revisions
213: Obliterating Old Road 213: Obliterating Old Road Minor Revisions
Minor Revisions
Section 201 Clearing and Grubbing
Section 207 Subgrade Preparation
Updated Section 207.3 to remove Subexcavation.
The Contractor shall ensure the top two (2) feet of borrow Materials in the finished Subgrade is comprised of Material with the design R-value.
Section 213: Obliterating Old Road
Section 209 Blading and Reshaping
Due to overlap in requirements and frequency of use, applicable sections
of 208: Linear Grading were combined with section 209: Blading and
Reshaping
203: Excavation, Borrow, and
Embankment Recall per Section 203.4.1 Rock
Excavation
203: Excavation, Borrow, and
Embankment
2014 Specification
Ripping Test. Material that cannot be broken down by one pass with a single tooth ripper mounted on a crawler-type tractor in low gear with a minimum net flywheel power rating of 255 hp;
2019 Specification
Ripping Test. Material that cannot be broken down with two passes parallel to construction centerlinewith a single tooth ripper mounted on a crawler-type tractor in low gear with a minimum net flywheel power rating of 255 hp;
203: Excavation, Borrow, and Embankment203.2.1.3 Borrow
Borrow shall consist of Contractor provided suitable Embankment Materials obtained from an
approved source outside the Right of Way, unless otherwise specified in the Contract.
The Contractor shall only utilize borrow when the following conditions are met, unless
approved otherwise by the Project Manager:
1. All unclassified excavation Material has be utilized in the Contractor’s current phase of
construction;
2. The Contractor has requested to begin Borrow operations and the Project Manager has
concurred; and
3. Embankment areas that require borrow have been bladed and cross sectioned by the
Contractor and provided to the Project Manager.
Borrow Material placed within two (2) Ft, vertically and laterally, of final Subgrade elevations
shall meet the design R-Value as shown in the Contract. Prior to borrow operations the Contractor
shall perform R-value testing in accordance with AASHTO T-190 at the best fit exudation pressure of
300 psi at each borrow source. This information shall be submitted to the Project Manager with the
request to begin borrow operations. During borrow placement, if the Project Manager observes
changes in soil properties, including gradation, plasticity limits, and/or additional soil
characteristics, then, at the Project Manager’s request, additional AASHTO T-190 tests may be
required, at the Contractors expense.
When Work conforming to Section 306, “Portland Cement or Lime Treated Subgrade” is
specified in the Contract, the Contractor shall perform sulfate testing in accordance with AASHTO
T290 at each borrow source. Sulfate content shall be determined and reported as parts per million
(ppm). Soils with sulfate contents equal to or greater than 2,000 ppm shall
not be used as borrow.
203: Excavation, Borrow, and Embankment
2014 Specification
203.2.1.4 Subexcavation – Associated with R-Value
and Deleterious Material
203.2.1.5 Unstable Subgrade Stabilization
2019 Specification
203.2.1.4 Unstable Subgrade Stabilization – References
203-A: Unstable Subgrade Stabilization
203.2.1.5 Unsuitable Material – Includes types of
unsuitable material and differentiates between
unsuitable and unstable materials.
203: Excavation, Borrow, and
EmbankmentConstruction Requirements
203: Excavation, Borrow, and Embankment
Method of Measure
203.4.3 Unclassified Excavation and Borrow
For each phase identified in the Contract the Contractor is required to
measure the original ground surface of all cut, fill and borrow areas.
For embankment and borrow areas the Contract is required to measure the
final surface once the operations are complete.
Earthwork quantities are calculated as the neat volume from the original
ground surface (less the existing Roadway surfacing) between the limits shown
on the plans, and/or authorized changes by the Project Manager, and the
new ground surface.
The Department will not apply any shrinkage or swell factor due to payment
being made on the final cross sectioned volume.
The measurements are performed by means of a survey using electronic XML-
compatible format for each phase of the project at 50-foot intervals and a
report is generated that summarizes the basis for the final volumes.
203: Excavation, Borrow, and
Embankment
203.5 Basis of Payment
2014 Specification
2019 Specification
203: Excavation, Borrow, and
Embankment
203.5.1 Double Handling
Department will pay for excavated Materials that require more than
one handling as identified in the Contract.
Paid for as the bid item unit price for each handling approved by
the Project Manager.
Double handling does not include excavated and borrow materials
requested by the Contractor for their convenience.
For example, stockpiling excess unclassified excavation material that will
be used in a later phase
Double handling shall not be paid, for Material that is excavated
and placed in the same phase of the project.
New 203A: Unstable Subgrade
Stabilization
Stabilization of unstable subgrade soils
encountered in non-borrow sections, such as
cuts or existing grades within and not
exceeding the top two (2) feet of finished
subgrade elevation…
Revised definition to clarify proof rolling.
Stabilization options may consist of mechanical
stabilization and/or reworking existing Materials.
206: Excavation and Backfill for Culverts and
Minor Structures
206.2. Materials
210: Excavation and Backfill for Major
Structures
Deleted 210.3.3 Contractor Certification of Backfill
Modified Method of Measure
Major Structure Excavation
Major Structure Backfill
210: Excavation and Backfill for Major
Structures
210.4.2 Major Structure Excavation
Measurement is made for each phase of the project based on the neat
volume below the original ground surface and the final excavated ground
surface.
Contractor is required to survey and submit the original ground surface and
the final excavated ground surface in a volume summary report.
Project Manager can request cross section intervals that adequately
quantify the volumes.
Volumes that do not count toward structure excavation are included in
210.4.1 (7 items).
210: Excavation and backfill for major
structures
210.4.2 Major Structure Backfill
Measurement is made for each phase of the project based on the cubic yard compacted in place.
Major structure backfill is calculated as the neat volume above existing or excavated ground surface and the final compacted ground surface.
Contractor is required to survey and submit the existing or excavated ground surface and the final compacted ground surface for each phase.
Project Manager can request cross section intervals that adequately quantify the volumes.
No measurement for payment will be made for additional backfill required due to slides, cave-ins, infilling, overexcavation or carelessness of the Contractor.
Questions
My Contact information:
Michelle R. Mann, P.E., [email protected] 505.490.1507
For Questions regarding the Specifications contact your CLE.
Thank you to all core and ad-hoc committee members that assisted with this effort