Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10)

Removal of Structures and Obstructions

2-02

The Contractor shall roughen, clean, and saturate existing concrete surfaces, against
which fresh concrete will be placed, in accordance with

Section 6-02.3(12)B

. When a

portion of existing concrete is to be removed without replacement, concrete shall be
removed to a clean line with a smooth surface of less than 1/16 inch profile.

2-02.3(2)A3 Use of Explosives for Bridge Demolition

Explosives shall not be used for bridge demolition, except as specifically allowed by the
Special Provisions.

2-02.3(3) Removal of Pavement, Sidewalks, Curbs, and Gutters

In removing pavement, sidewalks, curbs, and gutters, the Contractor shall:
1. Haul broken-up pieces into the Roadway embankment or to some off-project site.
2. Material that is to be incorporated into the embankment shall be broken into pieces

not exceeding 18 inches in any dimension, and no part of any piece shall be within 3
feet of the top, side, or end surface of the embankment or any Structure.

3. Make a vertical full depth saw cut between any existing pavement, sidewalk, curb,

or gutter that is to remain and the portion to be removed. For concrete pavement
removal, a second vertical full depth relief saw cut offset 12 to 18 inches from and
parallel to the initial saw cut is also required, unless the Engineer allows otherwise.
For removal of bituminous pavement, asphalt planing equipment may be used in lieu
of sawcutting provided that a clean vertical edge remains.

4. Replace at no expense to the Contracting Agency any existing pavement designated

to remain that is damaged during the removal of other pavement.

2-02.4 Vacant
2-02.5 Payment

Payment shall be made for the following Bid item when it is included in the Proposal:

“Removal of Structures and Obstructions”, lump sum.
If pavements, sidewalks, curbs, or gutters lie within an excavation area, their removal
will be paid for as part of the quantity removed in excavation.
“Removing Existing Bridge___”, lump sum.
“Removing Existing Structure___”, lump sum.
“Removing Portion of Existing Bridge___”, lump sum.
“Removing Portion of Existing Structure___”, lump sum.

Page 2-8

Roadway Excavation and Embankment

2-03

Roadway Excavation and Embankment

2-03.1 Description

The Work described in this section, regardless of the nature or type of the materials
encountered, includes excavating and grading the Roadway, excavating in borrow pits,
excavating below grade, excavating channels and ditches, removing slide material, and
disposing of all excavated material. These activities may be performed in making cuts,
embankments, slopes, Roadway ditches, approaches, parking areas, Highway-driveway
intersections, and in completing related Work. The Work includes the removal of
pavement, sidewalks, curbs and gutters as described in

Section 2-02

when these items lie

within an excavation area.

The Work excludes these items if they are designated as pay items in the Contract:
1. Haul.
2. Excavation for Structures and ditches.
3. Removal of unsuitable materials.

The Plans may divide the project into separate areas (Roadway Excavation, Area A,
Roadway Excavation, Area B, etc.). Such division does not imply any classification of
materials in the areas. The boundaries of the areas shall not be changed regardless of how
similar or dissimilar the materials are from one area to another.

All Work described here must reasonably conform to the alignment, grade, and
cross-sections shown in the Plans or established by the Engineer.

2-03.2 Vacant
2-03.3

Construction Requirements

2-03.3(1) Widening of Cuts

If routine cuts do not supply enough material to form the embankment, the Contractor
shall obtain more material from areas inside or outside the Right of Way and/or from
widening one or both sides of existing cuts as determined by the Engineer. The Contractor
shall dress the sides of the cuts to any slopes the Engineer may require. If the Contractor
has dressed a cut before the Engineer determines to widen it, the Contracting Agency will
pay for the resloping as provided in

Section 1-04.4

. In addition, material obtained from

areas beyond the cuts shown in the Plans that result in additional haul will be paid by the
Contracting Agency as provided in

Section 1-04.4

Roadway Excavation and Embankment

2-03

2-03.3(2) Rock Cuts

1. Preserving Rock Below Subgrade – The Contractor shall take care not to break

down, loosen, or damage the rock under the Subgrade line, except as provided by

Section 2-03.3(3)

. Normally cuts will be made from the top, lift by lift, to protect the

rock bench that will remain. The Contractor shall be responsible for methods used
and for any damage caused to the Roadbed, regardless of any previous approvals by
the Engineer.

2. Scaling and Dressing – To leave rock cuts in a safe, stable condition, the Contractor

shall scale and dress them, removing all loose fragments and rocks not firmly
fastened to the rock slope. The Contractor shall also remove any overhanging rock
the Engineer sees as a hazard to Roadway users.

If the Engineer requires it, the Contractor shall remove loose fragments and rocks
lying outside the slope stakes. Payment for such extra Work shall be by force
account as provided in

Section 1-09.6

. The Contracting Agency will pay for loading

and hauling these materials at the unit Contract prices that apply or as provided in

Section 1-04.4

3. Drilling and Blasting – Not less than 2 weeks prior to commencing drilling and

blasting operations or at any time the Contractor proposes to change the drilling and
blasting methods, the Contractor shall submit a Type 2 Working Drawing consisting
of a blasting plan. The blasting plan shall contain the full details of the drilling and
blasting patterns and controls the Contractor proposes to use for both the controlled
and production blasting. The blasting plan submittal is required for all blasting
operations and shall contain at least the following information:
a. Station limits of proposed shot.
b. Plan and section views of proposed drill pattern including free face, burden,

blast hole spacing, blast hole diameter, blast hole angles, lift height, and subdrill
depth.

c. Loading diagram showing type and amount of explosives, primers, initiators, and

location and depth of stemming.

d. Initiation sequence of blast holes including delay times and delay system.
e. Manufacturer’s data sheets for all explosives, primers, and initiators to be

employed.

Review of the blasting plan by the Engineer shall not relieve the Contractor of the
responsibility for the accuracy and adequacy of the plan when implemented in
the field.

4. Controlled Blasting – When blasting to establish slopes 0.5:1 or steeper, and more

than 10 feet high, the Contractor shall use controlled blasting. The Engineer may
require the Contractor to use controlled blasting to form the faces of other slopes,
even if the slopes could be formed by nonblasting methods.

Page 2-10

Roadway Excavation and Embankment

Controlled blasting refers to the controlled use of explosives and blasting accessories
in carefully spaced and aligned drill holes to provide a free surface or shear plane in
the rock along the specified backslope. Controlled blasting techniques covered by
this Specification include presplitting and cushion blasting.

In addition to the blasting plan submittal, when using controlled blasting the
Contractor shall:
a. Prior to commencing full-scale blasting operations, the Contractor shall

demonstrate the adequacy of the proposed blast plan by drilling, blasting, and
excavating short test sections, up to 100 feet in length, to determine which
combination of method, hole spacing, and charge works best. When field
conditions warrant, the Contractor may be ordered to use test section lengths
less than 100 feet.

Unless otherwise allowed by the Engineer, the Contractor shall begin the
tests with the controlled blast holes spaced 30 inches apart, then adjust if
needed, until the Engineer accepts the spacing to be used for full-scale blasting
operations.

b. The Contractor shall completely remove all overburden, soil, and loose

or decomposed rock along the top of the excavation for a distance of at least
30 feet beyond the end of the production hole drilling limits, or to the end of
the cut, before drilling the presplitting holes.

c. The controlled blast holes shall be not less than 2½ inches nor more than

3 inches in diameter.

d. The Contractor shall control drilling operations by the use of the proper

equipment and technique to ensure that no hole deviates from the plane of the
planned slope by more than 9 inches either parallel or normal to the slope. Drill
holes exceeding these limits will not be paid for unless satisfactory slopes are
being obtained.

e. Controlled blast holes shall extend a minimum of 30 feet beyond the limits of

the production holes to be detonated, or to the end of the cut as applicable.

The length of controlled blast holes for any individual lift shall not exceed
20 feet unless the Contractor can demonstrate to the Engineer the ability to
stay within the above tolerances and produce a uniform slope. If greater than
5 percent of the presplit holes are misaligned in any one lift, the Contractor
shall reduce the height of the lifts until the 9-inch alignment tolerance is met.
Upon satisfactory demonstration, the length of holes may be increased to a
maximum of 60 feet with written acceptance of the Engineer.

g. When the cut height requires more than one lift, a maximum 2-foot offset

between lifts will be permitted to allow for drill equipment clearances. The
Contractor shall begin the controlled blast hole drilling at a point that will allow
for necessary offsets and shall adjust, at the start of lower lifts, to compensate
for any drift that may have occurred in the upper lifts.

Roadway Excavation and Embankment

2-03

h. Before placing charges, the Contractor shall determine that the hole is free of

obstructions for its entire depth. All necessary precautions shall be exercised so
that the placing of the charges will not cause caving of material from the walls
of the holes.

The maximum diameter of explosives used in presplit holes shall not be greater
than ½ the diameter of the presplit hole.

Only standard explosives manufactured especially for controlled blasting shall
be used in controlled blast holes, unless otherwise allowed by the Engineer.
Bulk ammonium nitrate and fuel oil (ANFO) shall not be loaded in the presplit
holes.

k. If fractional portions of standard explosive cartridges are used, they shall be

firmly affixed to the detonating cord in a manner that the cartridges will not
slip down the detonating cord nor bridge across the hole. Spacing of fractional
cartridges along the length of the detonating cord shall not exceed 30 inches
center to center and shall be adjusted to give the desired results.

Continuous column cartridge type of explosives used with detonating cord
shall be assembled and affixed to the detonating cord in accordance with the
explosive manufacturer’s instructions, a copy of which shall be submitted
as a Type 1 Working Drawing.

m. The bottom charge of a presplit hole may be larger than the line charges but

shall not be large enough to cause overbreak. The top charge of the presplitting
hole shall be placed far enough below the collar, and reduced sufficiently,
to avoid overbreaking and heaving.

n. The upper portion of all presplit holes, from the top most charge to the hole

collar, shall be stemmed. Stemming materials shall be sand or other dry angular
material, all of which passes a ⅜-inch sieve.

o. If presplitting is specified, the detonation of these holes shall be fired first.
p. If cushion blasting is specified, the detonation of these holes shall be fired

last on an instantaneous delay after all other blasting has taken place in the
excavation.

q. Production blast holes shall not be drilled closer than 6 feet to the controlled

blast line, unless otherwise allowed by the Engineer. The bottom of the
production holes shall not be lower than the bottom of the controlled blast
holes. Production holes shall not exceed 6 inches in diameter, unless otherwise
allowed by the Engineer. Detonation of production holes shall be on a delay
sequence toward a free face.

The use of horizontal blast holes for either production or controlled blasting
is prohibited.

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Roadway Excavation and Embankment

2-03.3(3) Excavation Below Subgrade

Rock Excavation – When the Contractor finds rock or other hard material at the Subgrade
elevation, it shall be excavated the full width of the Roadbed to at least 6 inches below
Subgrade, then backfilled with rock fragments, gravel, or other free-draining material not
more than 4 inches in diameter.

If the Contractor uses a Subgrade trimmer, the backfill shall be rock, gravel, or other
free-draining material not more than 2 inches in diameter. The Contractor shall save the
finer free-draining material from excavations or borrow pits to use in backfilling the top
6 inches of the Subgrade. All such material shall be approved by the Engineer.

Sub excavation – At any time, the Engineer may order excavation below Subgrade to
remove soft and uncompactible material. The replacement material shall be free-draining
and granular, or other materials as determined by the Engineer.

Draining Rock Pockets – If blasting below Subgrade leaves a rock pocket that will not
drain, the Contractor shall dig a trench from the pocket bottom to the roadside ditch,
then backfill both the pocket and the trench with rock fragments, gravel, or other material
approved by the Engineer, at no expense to the Contracting Agency.

Compaction – If the density of the natural earth under any area of the Roadway is
less than that required in

Section 2-03.3(14)C

, Method B, the Engineer may order the

Contractor to perform any or all of the following:
1.  Scarify the earth to a depth of 6 inches.
2.  Aerate or water.
3.  Compact the scarified area to the required density.
4.  Excavate to a specific depth.
5.  Backfill the excavated area in layers, using the previously excavated material

or other material.

6. Compact each layer to meet the compaction requirements for embankments.

2-03.3(4) Sluicing

The Contractor shall not excavate by sluicing unless the Special Provisions specifically
call for it.

2-03.3(5) Slope Treatment

The tops of all Roadway cut slopes, except solid rock cuts, shall be rounded in accordance
with the

Standard Plans

. Unless otherwise noted in the Plans or Special Provisions, Class A

slope treatment shall be utilized.

If a layer of earth covers a rock cut, the slope shall be rounded above the rock as if it were
an earth slope.

Roadway Excavation and Embankment

2-03

When the Contractor removes stumps or any embedded material from the rounded area,
the void shall be backfilled and stabilized to prevent erosion.

All Work required to complete slope treatment, including excavation, haul, and slope
rounding, shall be included in the unit Bid price for Roadway excavation.

2-03.3(6) Deposit of Rock for the Contracting Agency’s Use

At the Engineer’s direction, the Contractor shall deposit excavated rock at the roadside
or elsewhere. If this requires the Contractor to use material that would otherwise have
gone into an embankment, the Contracting Agency will pay for the extra cubic yards
of excavation needed to complete the embankment. Any such rock deposit shall be
Contracting Agency property. The Contractor shall be responsible for safekeeping the
deposit until the Contracting Agency has removed it or until the Contract is completed.

2-03.3(7) Disposal of Surplus Material

2-03.3(7)A General

The Contractor shall haul all excavation to the nearest embankment unless the Engineer
declares the hauling distance to be too great. If excavation yields more material than
needed for nearby embankments, the Contractor shall dispose of the excess in keeping
with the Special Provisions or as the Engineer directs.

2-03.3(7)B Haul

When the Contract includes a payment item for haul, the Contracting Agency will pay
as follows for hauling excess excavation to a disposal site:
1. If the Contracting Agency provides a site, but the Contractor chooses to haul

elsewhere, the Contracting Agency will pay for the actual distance up to but not
exceeding the distance that would have been necessary using the Contracting
Agency site.

2. If the Contracting Agency does not provide a site, the Contracting Agency will pay

for the actual distance up to but not exceeding the distance necessary to haul to a
site 1 mile from the project limits.

2-03.3(7)C

Contractor-Provided Disposal Site

If the Contracting Agency provides no waste site, but requires disposal of excess
excavation or other materials, the Contractor shall arrange for disposal at no expense to
the Contracting Agency, except as provided in

Section 2-03.3(7)B

, item 2.

The Contractor shall acquire all permits and approvals required for the use of the disposal
sites before any waste is hauled off the project. The Contractor shall submit a Type 1
Working Drawing consisting of copies of the permits and approvals for any disposal sites
to be used. The cost of any such permits and approvals shall be included in the Bid prices
for other Work.

Page 2-14

Roadway Excavation and Embankment

Disposal of excess material within a wetland area will not be allowed without a
Section 404 permit issued by the U.S. Corps of Engineers and approval by the local
agency with jurisdiction over the wetlands.

The Contractor shall protect, indemnify, and save harmless the Contracting Agency
from any damages that may arise from the Contractor’s activities in making these
arrangements. Such indemnity shall be in accordance with

RCW 4.24.115

as amended

by CH. 305, Laws of 1986. Any action required to satisfy any permit and/or any approval
requirements in a Contractor-provided disposal site shall be performed by the Contractor
at no additional expense to the Contracting Agency.

Reclamation of a Contractor-supplied waste site must conform to the requirements of

Section 3-03

2-03.3(8) Wasting Material

If, against the Engineer’s orders, the Contractor wastes material needed for the
embankment, it shall be replaced at no expense to the Contracting Agency with material
the Engineer approves.

2-03.3(9) Roadway Ditches

At each transition from cut to fill, the Contractor shall divert any Roadway ditch away
from the embankment in natural ground. Ditches shall never permit water to flow into
or upon embankment material.

2-03.3(10) Selected Material

When the Contract or the Engineer calls for it, selected material shall be used for finishing
the top part of the Subgrade, for structural or other backfill, or for other purposes. Unless
the Special Provisions specify otherwise, the Engineer may identify as “selected” any
material excavated within the right-of-way, including the excavation of local borrow.

Direct Hauling – If it is practical, the Contractor shall haul selected material immediately
from excavation to its final place on the Roadbed. The Contracting Agency will pay for
such Work at the unit Contract prices for excavating, hauling, watering, and compacting.

Delayed Excavation – If it is impractical to haul selected material to its final place at
once, the Contractor shall delay excavation until the placement will be workable. The
Contracting Agency will not pay extra for delayed excavation.

Stockpiling – The Engineer may allow the Contractor to stockpile selected materials
if delaying the excavation will hamper grading or force impractical movements of
equipment. In this case, the Engineer will direct where and when the Contractor shall
excavate, stockpile, haul, and place the selected materials.

describe how the Contracting Agency will measure and pay

for excavating and hauling these stockpiled selected materials. The neat line volume of
material removed will provide the basis for measuring material taken from the stockpile.

Roadway Excavation and Embankment

2-03

2-03.3(11) Slides

If a slide occurs on a finished slope before final acceptance of the Work, the Contractor
shall remove or replace the slide material. The Contractor shall also refinish the slope to
the condition and with the materials required by the Engineer.

The Contracting Agency will pay for the excavation at the unit Contract price and
for resloping on a force account basis. The Engineer may authorize payment for the
excavation by agreed price or force account if:
1. The slide material cannot be measured accurately, or
2. Excavation of slide material requires equipment not available on the project.

If the Contractor undercuts or destroys a slope, or has failed to implement erosion
control devices as shown in the Contract or in the TESC plan, it shall be resloped to the
original alignment or to a new one established by the Engineer at no expense to the
Contracting Agency.

2-03.3(12) Overbreak

Overbreak includes that part of any material excavated, displaced, or loosened outside
the staked or reestablished slope or grade. Such material is considered overbreak whether
its movement resulted from blasting, from the character of the material itself, or from any
other cause. Overbreak, however, does not include material from slides as described in

Section 2-03.3(11)

If the Engineer does not approve use of the overbreak, the Contractor shall remove, haul,
and dispose of it at no expense to the Contracting Agency. In this case, the Contractor
shall follow the procedure for handling surplus described in

Section 2-03.3(7)

If the Engineer approves, the Contractor may use overbreak:
1. To complete an embankment when the excavated material unexpectedly falls short

of the amount required. The Contracting Agency will pay the Roadway excavation
Contract price for the volume of material the overbreak replaces, and will pay the
Contract price for haul. However, no payment will be made if overbreak is used when
other material is available within the neat lines of the Roadway prism.

2. To replace borrow excavation originally planned for an embankment. The Contracting

Agency will pay for overbreak used this way at the unit Contract price for Roadway
or borrow excavation, whichever costs less. The Engineer will include haul to be paid
as in the original Proposal in comparing the costs under the two payment methods.

2-03.3(13) Borrow

Borrow is the excavation of material outside the Roadway prism or outside the limits of
any other excavation area required by the Contract. Before any borrow site can be used, it
must be measured and approved by the Engineer. Any material excavated from a borrow
site before the site is measured will not be paid for. The widening of Roadway cuts and
ditches will be considered Roadway excavation, not borrow.

Page 2-16

Roadway Excavation and Embankment

If the Contract documents designate borrow sources, the Contractor may utilize those
sources or may obtain borrow from other sites. If borrow is obtained from a Contractor-
provided site, there will be no additional cost to the Contracting Agency beyond
the Contract unit price for the excavated borrow material. There will be no payment
for aeration of the borrowed material from a Contractor-provided site, even if the
Contract contains an item for aeration and even if the Contract documents designate
borrow sources.

If neither the Plans nor the Special Provisions name a source for borrow, the Contractor
shall provide a source at no expense to the Contracting Agency.

The Contractor shall reclaim all borrow sites, Contracting Agency-owned, Contracting
Agency-supplied, or obtained by the Contractor, in keeping with

Section 3-03

2-03.3(14) Embankment Construction

The Contracting Agency classifies embankment construction as:
1. Rock Embankment – In which the material in all or any part of an embankment

contains 25 percent or more, by volume, gravel or stone 4 inches or more in
diameter.

Section 2-03.3(14)A

2. Earth Embankment – Made of any material other than that used in rock

embankment.

Section 2-03.3(14)B

Unstable Base – If the Engineer believes the natural earth base will impair an
embankment or make it unstable, the Contractor shall stabilize or remove and dispose of
the base material in keeping with this section or

Section 2-03.3(14)E

Hillside Terraces – The Contractor shall terrace the original ground or embankment when
the slope of the surface is 2H:1V or steeper unless otherwise directed by the Engineer.
The face of each terrace shall be a minimum of 1 foot and a maximum of 5 feet in
height and shall be vertical or near vertical as required to remain stable during material
placement and compaction. The bench of the terrace shall slope outward to drain and
shall not be inclined steeper than 0.05 foot per foot. Terraces damaged during work shall
be reestablished. The Engineer may order the Contractor to place gravel backfill, pipe
drains or both to drain any seepage.

All costs for building terraces shall be included in the prices for other Work.

Soft Base – On wet or swampy ground, the Contractor shall haul and spread embankment
material by methods that will disturb the base as little as possible. If the Engineer
approves, the Contractor may place the lower part of the fill by dumping and spreading
successive loads to form a uniform layer just thick enough to support equipment used to
place and compact upper layers.

Roadway Excavation and Embankment

2-03

Normally the Contractor shall not increase the planned depth of the embankment over
a soft base merely to permit the use of heavier equipment. But if the Contractor proves
that the planned depth will not support light hauling vehicles, the Engineer may approve
a deeper fill. The Contractor shall not claim extra pay if these restrictions require the use
of lighter equipment or different construction methods than originally planned for use on
the soft base.

2-03.3(14)A

Rock Embankment Construction

The Contractor shall build rock embankments in horizontal layers. No layer shall be
deeper than 18 inches unless the rocks in the fill material average more than 18 inches
in diameter. The Contractor shall separate and distribute the larger pieces of rock and fill
the spaces between them with smaller rocks and earth. With the Engineer’s approval, the
Contractor may dispose of rocks larger than the average size instead of placing them in
the embankment.

Compacting – The Contractor shall use a 50-ton compression roller or a vibratory roller
having a dynamic force of at least 40,000 pounds impact per vibration and at least
1,000 vibrations per minute. In either case, the roller shall make one full coverage for each
6 inches, or any fraction of 6 inches, of lift depth.

When lift depth is 18 inches or less, the Contractor may use a 10-ton compression roller
or a vibratory roller having a dynamic force of at least 30,000-pounds impact per vibration
and at least 1,000 vibrations per minute. In either case, the roller shall make four full
coverages for each 6 inches, or any fraction of 6 inches, of lift depth.

Rollers must exert reasonably even pressure over the area covered. The Contractor shall
limit the speed of compression rollers to no more than 4 mph, and the speed of vibratory
rollers to no more than 1½ mph.

If possible, the Contractor shall compact the material even further by routing empty and
loaded hauling equipment evenly over the entire width of the embankment.

When the Engineer believes rolling to be physically impractical, rolling may be omitted on
part or all of a layer.

Should excessive moisture threaten the stability of the embankment the Engineer may
order the Contractor to alter the operation. This may include alternating layers of wet and
dry materials, drying materials before placing, or halting Work in the problem areas. In
this case the Contracting Agency will not increase payment, but will pay the unit Contract
prices for the pay items that apply.

Top Layer – The Contractor shall build each rock embankment up to 6 inches below
Subgrade. The top 6-inch layer of embankment shall be of rock, gravel, or other free-
draining material that does not exceed 4 inches in diameter. When the Plans require
use of a Subgrade trimmer, these materials in the top layer may not exceed 2 inches
in diameter.

Page 2-18

Roadway Excavation and Embankment

When practical, and as approved by the Engineer, the Contractor shall save the finer
free-draining material from excavations or borrow pits for use in topping rock fills. If
selected materials suitable for topping are available, the Contracting Agency will pay for
them as described in

Section 2-03.3(10)

. If such materials are not available on site, the

Contracting Agency will pay for imported materials by including them in the unit Contract
price for gravel borrow or borrow excavation, each including haul. If the Proposal does not
include these items, the Contracting Agency will pay as provided in

Section 1-04.4

2-03.3(14)B

Earth Embankment Construction

The Contractor shall place earth embankments in horizontal layers of uniform thickness.
These layers shall run full width from the top to the bottom of the embankment. Slopes
shall be compacted to the required density as part of embankment compaction.

During grading operations, the Contractor shall shape the surfaces of embankments and
excavations to uniform cross-sections and eliminate all ruts and low places that could hold
water. The Contractor shall raise the center of an embankment above the sides. When the
surface of an embankment intersects a side hill, the surface shall be sloped away at a rate
not to exceed 20:1.

2-03.3(14)C

Compacting Earth Embankments

This section describes three methods (A, B, and C) for building earth embankments. The
Contractor shall use Method B unless the Special Provisions require another method.

Method A – Each embankment shall be made of layers no more than 2 feet thick. The
Contractor shall compact each layer by routing loaded haul equipment over its entire
width. If the Engineer approves, the Contractor may use end dumping to begin placing a
side hill fill too narrow for hauling equipment. When the fill is wide enough, the remaining
layers shall be compacted by the loaded hauling equipment.

Method B – The top 2 feet of each embankment shall be compacted to 95 percent
of the maximum density as determined by the compaction control tests described in

Section 2-03.3(14)D

. All material below the 2-foot level shall be compacted to 90 percent

of the same maximum density.

In the top 2 feet, horizontal layers shall not exceed 4 inches in depth before compaction.
No layer below the top 2 feet shall exceed 8 inches in depth before compaction.

The Contractor shall use compacting equipment approved by the Engineer.

Method C – Each layer of the entire embankment shall be compacted to 95 percent
of the maximum density as determined by the compaction control tests described in

Section 2-03.3(14)D

In the top 2 feet, horizontal layers shall not exceed 4 inches in depth before compaction.
No layer below the top 2 feet shall exceed 8 inches in depth before compaction.

The Contractor shall use compacting equipment approved by the Engineer.

Roadway Excavation and Embankment

2-03

Under Methods B or C, the Engineer may permit the Contractor to increase layer
thickness up to 18 inches before compaction, provided:
1.  The layer is more than 2 feet below the top of the embankment,
2.  An approved vibratory roller is used, and
3.  The required density is obtained throughout the full depth and width of each layer.

Whatever the method used, any embankment inaccessible to large compacting equipment
shall be compacted with small mechanical or vibratory compactors.

Moisture Content – The Contractor shall adjust moisture content during compaction to
produce a firm, stable and unyielding embankment. The embankment shall be free from
pumping and rutting due to excessive moisture and is the Contractor’s responsibility to
manage and adjust as necessary.

The Contracting Agency will consider all costs for drying embankment material to be
incidental to other Work, including excessive moisture due to inclement weather. If,
however, the Contract includes an aeration item, the Contracting Agency will pay for such
Work as specified in

Sections 2-03.4

and

2-03.5

The Contractor shall repair, at no expense to the Contracting Agency, any partial
or complete embankment that loses stability because of continued hauling across
it. Evidence of lost stability includes pumping, rutting or lateral displacement of
embankment. The Contractor shall also alter hauling equipment or procedures to prevent
further damage.

2-03.3(14)D Compaction and Moisture Control Tests

Maximum density and optimum moisture content shall be determined by one of the
following methods:
1. Materials with less than 30 percent by weight retained on the No. 4 sieve shall be

determined using FOP for AASHTO T 99 Method A.

2. Materials with 30 percent or more by weight retained on the No. 4 sieve and less

than 30 percent retained on the ¾-inch sieve shall be determined by WSDOT

T 606

or FOP for AASHTO T 180 Method D. The determination of which test procedure to
use will be made solely by the Contracting Agency.

3. Materials with 30 percent or more retained on the ¾-inch sieve shall be determined

by WSDOT

T 606

In place density will be determined using Test Methods FOP for AASHTO T 310 and
WSDOT

SOP 615

Page 2-20

Roadway Excavation and Embankment

2-03.3(14)E

Unsuitable Foundation Excavation

When the Contract or the Engineer requires it, the Contractor shall excavate unstable
natural ground before building any embankment over it. This unstable material may
include peat, muck, swampland, buried logs and stumps, or other material not fit for an
embankment base. The Contractor shall excavate such material to the boundaries set by
the Engineer.

The Work will not be considered unsuitable foundation excavation if the materials:
1.  Came from the Roadway cut, ditch, or channel-change prisms.
2.  Resulted from Structure excavation Class A or B.
3.  Are covered in

Section 2-03.3(3)

If the Contract provides no Bid item for unsuitable foundation excavation, the Contracting
Agency will pay as provided in

Section 1-04.4

2-03.3(14)F Vacant
2-03.3(14)G Backfilling

When water fills an area after the removal of soft or unstable materials, the Contractor
shall, if possible, drain the site so that any backfill may be compacted. If drainage is not
possible, the Contractor shall use granular material for backfilling in water, including areas
where blasting has displaced the soft material. The Special Provisions may require other
backfilling methods.

The costs of pumping or digging temporary drainage ditches shall be incidental to and
included in other items of Work that apply.

2-03.3(14)H Prefabricated Vertical Drains

The Contractor shall furnish all necessary labor, equipment and materials, and perform
all operations necessary for the installation of prefabricated vertical drains in accordance
with the details shown in the Plans and with the requirements of these Specifications.

The prefabricated drain shall consist of a continuous plastic drainage core wrapped in a
nonwoven geotextile material as specified in the Contract.

The drains shall be free of defects, rips, holes, or flaws. During shipment and storage, the
drain shall be wrapped in a heavy-duty protective covering. The storage area shall protect
the drain material from sunlight, mud, dirt, dust, debris, and detrimental substances.
Manufacturer certification shall be provided for all drain materials delivered to the project.

Vertical drains shall be staked by the Contractor and constructed prior to embankment
construction.

Prior to installation of vertical drains, a sand drainage blanket shall be placed on the
ground surface for use as a working platform. This platform shall have a minimum
depth of 2 feet and shall consist of uncompacted material meeting the requirements of

Section 9-03.13(1)

Roadway Excavation and Embankment

2-03

Vertical drains shall be installed with equipment that will cause a minimum of subsoil
disturbance. A mandrel or sleeve shall be advanced through the subsoil using vibratory,
constant load, or constant rate of advance methods. The mandrel shall have a maximum
cross-sectional area of 14 square inches, shall protect the prefabricated drain material
from tears, cuts, and abrasions during installation, and shall be provided with an “anchor”
plate or rod. The “anchor” plate or rod shall provide sufficient strength to prevent the soil
from entering the bottom during installation and shall anchor the bottom of the drain at
the required depth when the mandrel is removed. Use of falling weight impact hammers
or jetting will not be allowed within the compressible subsoil to be drained.

The prefabricated drains shall be installed vertically from the working surface to the
required elevations and in a sequence that will not require equipment to travel over
previously installed drains. The Contractor shall provide the Engineer with a suitable
means of verifying the plumbness of the equipment and determining the depth of the
drain at any time. The equipment shall not deviate more than 0.25 inches per foot from
vertical.

Splices or connections in the prefabricated drain material shall be done in a professional
manner to ensure continuity of the wick material. The prefabricated drain shall be cut to
leave at least 6 inches protruding above the working platform at each drain location.

Where obstructions are encountered which cannot be penetrated the Contractor shall
abandon the hole. A maximum of two attempts shall be made to install a new drain within
18 inches of the obstructed hole. Drains that otherwise deviate from the Plan location by
more than 6 inches, or that are damaged or improperly installed, will be rejected.

Installation of the drains should consider and be coordinated with the geotechnical
instrumentation shown in the Plans. Special care shall be taken when installing drains
near instrumentation already in place. Replacement of instrumentation damaged by the
Contractor will be the responsibility of the Contractor.

The Contractor shall demonstrate that the equipment, method, and materials produce
a satisfactory installation in accordance with these Specifications. For this purpose,
the Contractor shall be required to install trial drains at different locations within the
Work area.

The Contractor shall submit a Type 2 Working Drawing consisting of details of the
sequence and method of installation. The submittal shall, at a minimum, contain the
dimensions and length of mandrel, a detailed description of the proposed method(s) for
overcoming obstructions, and the proposed method(s) for splicing drains.

Approval by the Engineer will not relieve the Contractor of the responsibility to install
prefabricated vertical drains in accordance with the Plans, Special Provisions, and these
Specifications. If, at any time, the Engineer considers the method of installation does
not produce a satisfactory drain, the Contractor shall alter the method and equipment
as necessary.

Page 2-22

Roadway Excavation and Embankment

2-03.3(14)I

Embankments at Bridge and Trestle Ends

This Work consists of filling around the ends of trestles and bridges, the area defined in

Section 1-01.3

. The Contractor shall begin and complete this Work as soon as possible

after each bridge is completed or when the Engineer requires.

The Contractor shall select fill material from the excavation sources elsewhere on the
project. Bridge Approach Embankments shall be compacted to at least 95 percent of
the maximum density as determined by the tests described in

Section 2-03.3(14)D

. In

any embankment area where piles will be installed, the Contractor shall remove all solid
material, rocks, broken concrete, etc., larger than 3 inches across that would interfere with
pile driving.

To prevent the bridge from being distorted or displaced, the Contractor shall place backfill
evenly around all sides and parts of the Structure. The Contractor shall not backfill any
abutment prior to placing the Superstructure. After the Superstructure is in place, use
of small compactors may be required to compact the backfill around the Structure.
Embankments and backfill behind the abutments shall be brought up in layers and
compacted concurrently. The difference in backfill height against each abutment shall not
exceed 2 feet unless otherwise allowed by the Engineer.

The Contractor may request to place the abutment backfill (either full or partial height)
prior to placement of the Superstructure by submitting Type 2E Working Drawings
consisting of calculations confirming that the abutment is stable, both for overturning
and sliding, without the Superstructure in place. The stability calculations shall assume a
loading of 30 lbs/ft

equivalent fluid pressure and include at least a 2-foot surcharge for

the backfill placement equipment. If the abutment backfill is allowed to be placed prior to
completion of the Superstructure, the Contractor shall bear any added cost that results
from the change.

The Contractor shall build the embankment under the bridge to the dimensions shown in
the

Standard Plans

or detailed in the Plans.

Cost related to all Work described in this section shall be incidental to other Work and
included in the unit Contract prices that apply.

2-03.3(14)J

Gravel Borrow Including Haul

When required by the Plans or the Engineer, the Contractor shall use gravel borrow
meeting the requirements of

Section 9-03.14(1)

to:

1.  Build structural embankments.
2.  Backfill excavation of unsuitable foundation material above the ground water table.
3.  Backfill below-grade excavation above the ground water table.
4.  Construct mechanically stabilized earth walls.
5.  Construct reinforced soil slopes.

Gravel borrow shall be compacted according to Sections

2-03.3(14)C

and

2-03.3(14)D

Standard Specifications for Road, Bridge, and Municipal Construction 2020 (M 41-10) - page 25