03E03/29/06

S255-03E.doc

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  Use on all projects where Mechanically stabilized retaining walls are
  specified.

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Section 255. - MECHANICALLY STABILIZED EARTH WALLS

[Delete the text of this section and substitute the
following:]{.underline}

Description

**255.01** This work consists of designing, furnishing, and constructing
mechanically stabilized earth (MSE) walls with steel (mesh or strip) or
geogrid reinforcement according to the details shown on the plans.

# Materials

**255.02** Conform to the following Section and Subsections:

> Concrete leveling pad 601
>
> Foundation fill 704.01
>
> Select wall backfill 704.13(a)
>
> Wall backfill 704.13(b)
>
> Wall facing fill 704.13(c)
>
> Plastic pipe 706.08(d)
>
> Geotextile 714.01
>
> Geocomposite sheet drain 714.02(b)
>
> Mechanically stabilized earth wall material 720.01

# Construction Requirements

**255.03 General.** Survey MSE wall locations according to Section 152
to acquire existing terrain data. Prepare and submit preliminary
installation drawings for MSE walls according to Subsection 104.03.
Drawings will include existing terrain cross-sections and elevations of
MSE walls. Do not prepare design drawings for MSE walls or disturb the
existing ground at wall locations until existing terrain data has been
acquired, incorporated into the preliminary drawings, and the CO has
approved the drawings. Once the CO has approved preliminary drawings,
submit design drawings according to Subsection 255.03(a).

Perform the work under Section 209. Grade the foundation to a width
equal to the length of reinforcing mesh or strips plus 20 inches.
Bedrock and boulder excavation to obtain the necessary base width may be
required. Excavate using equipment capable of removing the material
while preventing material escape outside the construction limits.
Excavate any loose, soft, or otherwise unsuitable material present at
foundation grade and replace with foundation fill in horizontal layers
that when compacted do not exceed 6 inches in depth. Compact the MSE
wall foundation according to Subsection 204.11.

For concrete-faced walls, provide a precast reinforced or nonreinforced
cast-in-place concrete leveling pad according to Section 601. Cure
cast-in-place leveling pads a minimum of 12 hours before placing wall
facing.

**(a) Design of MSE Walls.** Using the approved preliminary drawings,
design all MSE wall components for a 75-year design service life
according to the requirements of AASHTO Standard Specifications for
Highway Bridges current at time of contract award and FHWA publication
No. FHWA-NHI-00-043, "Mechanically Stabilized Earth Walls and Reinforced
Soil Slopes Design and Construction Guidelines" (2001). Other design
methods will not be allowed. Design the MSE walls for:

> **(1)** External stability including: sliding, overturning, bearing
> capacity, and eccentricity.
>
> **(2)** Internal stability including: tensile stresses, pullout,
> facing connection, and sliding along reinforcement.

**(3)** Local stability including: bulging and maximum unreinforced
height.

> **(4)** Design the MSE wall to account for dead and live loads,
> seismic loads, horizontal loads from guardrails or barriers,
> hydrostatic loads, and other loads as appropriate.
>
> **(5)** Design the MSE wall such that the toe is at a depth that no
> scouring or undermining will occur.

Use Table 255-1 for required factors of safety per AASHTO for MSE wall
stability design:

**Table 255-1**

Required Factors of Safety

+----------------------------------+---------------+------------------+
| ##### External Stability         | ###### Static | **Seismic (A \>  |
|                                  |               | 0.09g)**         |
+----------------------------------+---------------+------------------+
| Base Sliding                     | 1.5           | 1.1              |
+----------------------------------+---------------+------------------+
| Overturning                      | 2.0           | 1.5              |
+----------------------------------+---------------+------------------+
| Bearing Capacity                 | 2.5           | 1.5              |
+----------------------------------+---------------+------------------+
| Eccentricity                     | e \< L/6      | e \< L/3         |
+----------------------------------+---------------+------------------+
| **Internal Stability**           | ##### Static  | **Seismic (A \>  |
|                                  |               | 0.09g)**         |
+----------------------------------+---------------+------------------+
| Tensile Stress:                  | 0.55Fy        | 0.73Fy           |
|                                  |               |                  |
| > Steel Mesh (wire-faced walls)  | 0.48Fy        | 0.64Fy           |
| >                                |               |                  |
| > Steel Mesh (concrete-faced     | 0.55Fy        | 0.73Fy           |
| > walls)                         |               |                  |
| >                                | 1.5           | 1.1              |
| > Steel Strips                   |               |                  |
| >                                |               |                  |
| > Geogrids                       |               |                  |
+----------------------------------+---------------+------------------+
| Pullout                          | 1.5           | 1.1              |
+----------------------------------+---------------+------------------+
| Facing Connection (for           | 1.5           | 1.1              |
| concrete-faced walls)            |               |                  |
+----------------------------------+---------------+------------------+
| Internal Sliding                 | 1.5           | 1.1              |
+----------------------------------+---------------+------------------+
| A: Acceleration coefficient, e:  |               |                  |
| Eccentricity, L: Reinforcement   |               |                  |
| length,                          |               |                  |
|                                  |               |                  |
| Fy: Yield strength of steel      |               |                  |
+----------------------------------+---------------+------------------+

> Table 255-2 lists available geotechnical report(s). General soil, rock
> strata descriptions, and indicated boundaries are based on engineering
> judgment and interpretation of available subsurface information, and
> may not reflect actual variation in subsurface conditions between
> borings and samples. The information has been prepared and is intended
> for Government design purposes. It is listed here for the purpose of
> providing intended users with access to the same information available
> to the Government.

**Table 255-2**

Available Geotechnical Reports

  --------------------------- ---------------------------- --------------
  **Title**                   **Author**                   **Date**

                                                           
  --------------------------- ---------------------------- --------------

Use soil parameters shown in Table 255-3 for the internal, external, and
local stability of the MSE retaining walls:

**Table 255-3**

Soil Design Parameters

+----------------------+-----------------+------------+----------------+
| ### **Material**     | **Friction      | **         | **Unit         |
|                      | Angle**         | Cohesion** | Weight**       |
|                      |                 |            |                |
|                      | **(degrees)**   | **(psf)**  | **(pcf)**      |
+----------------------+-----------------+------------+----------------+
| Select Backfill      | 34              | 0          | 125            |
+----------------------+-----------------+------------+----------------+
| Wall Backfill        | 30              | 0          | 120            |
+----------------------+-----------------+------------+----------------+
| Foundation Soil      | 30              | 0          | 120            |
+----------------------+-----------------+------------+----------------+

> Use permanent retaining wall systems that have previously been
> successfully designed and constructed for a public highway agency in
> the United States, and that have performed in an acceptable manner.
> The following wire-faced retaining wall systems have been previously
> constructed on CFLHD projects. For all wire-faced wall systems, submit
> the required information listed in Subsection 255.03(b). For
> wire-faced systems not listed below and all concrete-faced wall
> systems, submit the required information listed in Subsections
> 255.03(b) and 255.03(c).

####### Hilfiker Retaining Wall

> 3900 Broadway
>
> P.O. Box 2012, #E
>
> Eureka, CA 95503
>
> \(800\) 762-8962

####### SSL Retaining Walls

> 4740 Scotts Valley Dr.
>
> Scotts Valley, CA 95066
>
> \(831\) 430-9300

####### The Reinforced Earth Company

> 8614 Westwood Center Drive
>
> Suite 1100
>
> Vienna, VA 22182-2233
>
> \(703\) 821-1175
>
> **Tensar Earth Technologies, Inc.**
>
> 5883 Glenridge Dr., Suite 200
>
> Atlanta, GA 30328
>
> \(800\) 292-4459
>
> **T & B Structural Systems, Inc.**
>
> 637 West Hurst Blvd.
>
> Hurst, TX 76053
>
> 817-280-9858

**(b) Design Submittal.** Submit four (4) sets of drawings and
supporting calculations according to Subsection 104.03. One set will be
returned with any comments and requests for revisions or additional
information. Allow 28 calendar days after received by the CO for review
and acceptance of the submittal. If revisions are required, make
corrections and resubmit four (4) revised sets. If the drawings and
calculations must be resubmitted, the time for review and acceptance
starts over. Upon acceptance, furnish five (5) complete sets of the
submittal to the CO. Do not order materials for MSE retaining walls
before the CO approves the submittal.

To avoid having submittals returned with a request for more information,
submittals should be organized in such a way to facilitate review for
conformance with design standards and evaluation of design cases and
loads. Include the following minimum information with the MSE wall
submittals:

> **(1)** Design calculations and information:
>
> *(a)* Design calculations including an index page to the calculations.
> Submit design calculations on sheets approximately 8.5 by 11 inches in
> size with the project number, wall location, date of preparation,
> initials of designer and checker, and page number at the top of the
> page.
>
> *(b)* Highway Innovative Technology Evaluation Center evaluation
> report (not required for wire-faced wall systems). Contact the
> following for copies of HITEC evaluation reports.
>
> Highway Innovative Technology
>
> Evaluation Center (HITEC)
>
> 1015 15^th^ Street NW, Suite 600
>
> Washington, DC 20005-2605
>
> Phone: 202-842-0555
>
> Fax: 202-789-5345
>
> E-mail: hitec@cerf.org
>
> *(c)* Design notes including an explanation of any symbols and
> computer programs used in the wall design.
>
> *(d)* Summary of soil parameters, loading conditions considered, and
> factors of safety, including all partial reduction factors, if any.
>
> *(e)* Summary of wall reinforcing elements used and their design
> properties.
>
> *(f)* Demonstrate the compatibility of the effective aperture (the
> average opening created between the facing mat and backing mat) with
> the specified MSE wall facing fill.
>
> *(g)* Provide a design analysis for each possible design situation.
>
> *(h)* Specify the applied bearing pressure at wall foundation.
>
> *(i)* Include one set of hand calculations for each unique design
> analysis if computer analysis other than MSEW per FHWA publication No.
> FHWA-NHI-00-043 is used.
>
> *(j)* Special details, cross-sections, and quantities.
>
> *(k)* A well-documented field construction manual describing in detail
> and with illustrations where necessary, the step-by-step construction
> process.
>
> **(2)** Drawings:
>
> *(a)* Submit design drawings on sheets approximately 11 by 17 inches
> in size with the project number, wall location, date of preparation,
> initials of designer, checker, and page number.
>
> *(b)* A plan view of the wall identifying:

*(1)* Offset from the construction centerline to the face of the wall at
its top and base at all changes in horizontal alignment.

> *(2)* Limit of widest reinforcement.
>
> *(3)* Centerline of any drainage structure or drainage pipes behind,
> passing through, or passing under the wall.
>
> *(4)* Horizontal and vertical curve data affecting the wall. Match
> lines or other details to relate wall stationing to centerline
> stationing.
>
> *(c)* An elevation view of the wall identifying:
>
> *(1)* Elevation at the top of the wall, at all horizontal and vertical
> breaks, and at least every 15.0 feet along the wall.
>
> *(2)* Elevations at the wall base or top of leveling pads.
>
> *(3)* Distance along the face of the wall to all steps in the wall
> base or leveling pads.
>
> *(4)* Length and type of reinforcement elements.
>
> *(5)* Distance along the face of the wall to changes in the length of
> the reinforcement.
>
> *(6)* Existing and final ground line along wall layout line.
>
> *(7)* Existing ground line at a horizontal distance equal to the bench
> width away from the bottom of the wall. Refer to the MSE wall detail
> sheet.
>
> *(8)* Listing of the summary of quantities.
>
> *(d)* General notes for construction of wall.
>
> *(e)* Wall Details:
>
> *(1)* Typical section of wall.
>
> *(2)* Wall batter.
>
> *(3)* Details for constructing walls around drainage facilities
> entering, exiting, and within MSE wall envelope.
>
> *(4)* Details for guardrail posts punching through the upper
> reinforcement layers.
>
> *(5)* Details for terminating walls and adjacent slope construction.

**(c) Supplemental Design Submittal.** Submit the following additional
information for wire-faced systems not listed at the end of Subsection
255.03(a) and all concrete-faced wall systems.

**(1)** Examples of successful projects (design, construction, and
in-service performance with a public agency).

> **(2)** Name, address, and telephone number of agency contact.
>
> **(3)** Narrative descriptions and photos of example projects.
>
> **(4)** Limitations and constraints of the system.
>
> **(5)** Details of wall elements (procedures for field and laboratory
> evaluation including instrumentation and special requirements, if
> any).
>
> **(6)** Material samples of reinforcing elements and connection
> devices.
>
> **(7)** Construction control specifications showing material type,
> certifications, field-testing, acceptance/rejection criteria, and
> placement procedures.
>
> **(8)** Typical unit costs, supported by data from actual projects.
>
> **(9)** Laboratory and field-test results which support the system
> design criteria.
>
> **(10)** Information substantiating all partial factors of safety used
> in establishing the reinforcement elements long-term design strength.
>
> **(11)** Additional information requested by the CO.

**(d) Temporary shoring.** When required, design temporary shoring using
one of the methods described in the California Trenching and Shoring
Manual current at time of contract award. The manual is available from
the California Department of Transportation or online at:

> [www.dot.ca.gov](http://www.dot.ca.gov/).

**255.04 Wall Erection.** Erect the wall according to the
specifications, the design drawings approved by the CO, and
manufacturer's recommendations. When requested, have an experienced
field representative from the wall system manufacturer available during
the first three days of wall erection and as otherwise requested by the
CO.

Place reinforcement elements horizontally on compacted fill at
elevations and dimensions shown on the approved design drawings. Orient
reinforcement elements with the highest strength axis perpendicular to
the wall alignment. Spliced reinforcement connections between shorter
pieces of reinforcement will not be allowed unless approved by the CO.
Prior to placing fill over reinforcement, place the next course of wall
units, pull the reinforcement taut, and anchor the reinforcement.

**(a) Concrete panel faced walls.** Erect panels by means of lifting
devices connected to the upper edge of the panel. Make the joint
openings 0.75 0.25 inches wide. Install joint material according to the
drawings. Cover all joints on the backside of the panels with a 12 inch
wide strip of type I-A geotextiles. Overlap geotextile splices a minimum
of 4 inches. Hold the panels in position with temporary wedges or
bracing during backfilling operations. Design and construct the wall and
components to meet Table 255-4.

**Table 255-4**

Concrete Panel Faced Wall Construction Tolerances

+--------------------------+-------------------------------------------+
| ###### Description       | ###### Requirement                        |
+--------------------------+-------------------------------------------+
| Wall batter              | Within 0.25 inches per 5.0 feet of wall   |
|                          | height and a maximum of 0.2% for the      |
|                          | overall wall height                       |
+--------------------------+-------------------------------------------+
| Wall height              | Within 0.125 inches per 10.0 feet of wall |
|                          | height and a maximum of 0.5 inches        |
+--------------------------+-------------------------------------------+
| Horizontal and vertical  | Within 0.5 inches at any point in the     |
| alignment                | wall when measured with a 10 foot         |
|                          | straightedge                              |
+--------------------------+-------------------------------------------+
| Reinforcement elevation  | Within 2.0 inches of design elevation and |
|                          | within 1.0 inch of the corresponding      |
|                          | connection elevation at the wall face     |
+--------------------------+-------------------------------------------+
| Reinforcement            | Within 2% from horizontal                 |
| inclination              |                                           |
+--------------------------+-------------------------------------------+

**(b) Wire-faced walls.** Connect, tighten, and anchor soil
reinforcement elements to the wall facing units before placing backfill.
Design and construct the wire-faced wall and components to have the
ability to compress up to 2 inches at each layer of reinforcement
without creating outward bulging of the facing elements. Design and
construct the wall and components to meet Table 255-5:

**Table 255-5**

Wire Faced Wall Construction Tolerances

+--------------------------+-------------------------------------------+
| ###### Description       | ###### Requirement                        |
+--------------------------+-------------------------------------------+
| Wall batter              | Within 2.0 inches per 10.0 feet of wall   |
|                          | height and 1% for the overall wall height |
+--------------------------+-------------------------------------------+
| Wall height              | Within 1.0 inch per 10.0 feet of wall     |
|                          | height and a maximum of 4.0 inches        |
+--------------------------+-------------------------------------------+
| Horizontal and vertical  | Within 2.0 inches at any point in the     |
| alignment                | wall when measured with a 10 foot         |
|                          | straightedge                              |
+--------------------------+-------------------------------------------+
| Separation of facing mat | Outside of facing mat within 1.5 inches   |
|                          | from wall facing fill at all locations    |
+--------------------------+-------------------------------------------+
| Reinforcement elevation  | Within 2.0 inches of the design elevation |
|                          | and within 2.0 inches above the           |
|                          | corresponding connection elevation at the |
|                          | wall face. Do not place reinforcement     |
|                          | below corresponding connection elevation. |
+--------------------------+-------------------------------------------+
| Reinforcement            | Within 2% from horizontal                 |
| inclination              |                                           |
+--------------------------+-------------------------------------------+

Include hardware cloth behind the wire face unless the D~15~ of the wall
facing fill gradation is larger than the effective wire face opening.
Place a Type II-B geotextile between the wall facing fill and select
wall backfill. Terminate wire-face wall at the beginning and end of each
lift with a return of the wall facing a minimum of 4 feet into the
backfill.

**(c) Segmental block wall.** Place the first course of modular block
wall units on top of and in full contact with the leveling pad. Place
units side by side for the full length of the wall such that adjoining
blocks are located according to the manufacturer's recommendations.
Place units so that only the front face of the unit is visible. Check
units for proper elevation and alignment. Install connection and/or
alignment devices as required by design. Fill voids in and around units
with unit fill as required by manufacturer's installation guidelines to
meet the required connection strength. Provide specifications for unit
fill meeting manufacturer's recommendations. Place a Type II-B
geotextile between unit fill and select wall backfill. If the unit fill
is required to meet connection strength specifications, completely fill
each course of block prior to proceeding to the next course. Place
reinforcement with a maximum vertical spacing per the HITEC evaluation
but not more than 2 times the block depth or 24 inches, whichever is
less. Remove all excess materials from the top of the units prior to
installing each succeeding block course. Design and construct the wall
and components to meet Table 255-6.

**Table 255-6**

Segmental Block Wall Construction Tolerances

+--------------------------+-------------------------------------------+
| ###### Description       | ###### Requirement                        |
+--------------------------+-------------------------------------------+
| Wall batter              | Within 1.0 inch per 10.0 feet of wall     |
|                          | height and a maximum of 0.5% for the      |
|                          | overall wall height                       |
+--------------------------+-------------------------------------------+
| Wall height              | Within 0.5 inches per 10.0 feet of wall   |
|                          | height and a maximum of 1.0 inch          |
+--------------------------+-------------------------------------------+
| Horizontal and vertical  | Within 1.0 inch at any point in the wall  |
| alignment                | when measured with a 10 foot straightedge |
+--------------------------+-------------------------------------------+
| Reinforcement elevation  | Within 2.0 inches of design elevation and |
|                          | within 1.0 inches below the corresponding |
|                          | connection elevation at the wall face     |
+--------------------------+-------------------------------------------+
| Reinforcement            | Within 2% from horizontal                 |
| inclination              |                                           |
+--------------------------+-------------------------------------------+

**255.05 Backfilling.** Backfill the reinforced volume with select wall
backfill in compacted lifts not to exceed 6 inches where hand compaction
is used or in compacted lifts not to exceed 9 inches where heavy
compaction equipment is used. Place, spread, and compact select wall
backfill over the reinforcement in a manner that prevents development of
slack in the reinforcement. Compact select wall backfill according to
Subsection 204.11. Ensure that no voids exist below the reinforcing
elements. Where the stabilized volume supports spread footings for
bridges or other structural loads, compact the top 5 feet to at least
100 percent of the maximum density according to AASHTO T-99 method C.

Use wall facing fill within 3.0 feet of the wall face. Place wall facing
fill in compacted lifts not exceeding 12 inches and densify using hand
operated equipment. Place wall facing fill in sequence with select wall
backfill such that the top of the adjacent materials are within 18
inches of one another. Do not damage or disturb the facing or
reinforcing elements. Do not operate equipment directly on top of the
reinforcing elements. Remove and replace all damaged, misaligned, or
distorted wall components.

Backfill and compact behind the reinforced volume with wall backfill
according to Subsections 204.10 and 204.11. At the end of the day's
operation, slope the last lift of fill away from the wall face to direct
surface runoff away from the wall face. Do not allow surface runoff from
adjacent areas to enter the wall construction area.

**255.06 Drainage.** Subsurface drainage is required. Install the
drainage system as shown in drawing "Special M605-A". The CO may require
supplemental drainage when seepage is identified in the excavation.

**255.07 Acceptance.** Structure excavation will be evaluated under
Section 209.

Select wall backfill, wall backfill, and wall facing fill will be
evaluated under Subsection 704.13. Foundation fill will be evaluated
under Subsection 704.01.

Material for mechanically stabilized earth walls, plastic pipe,
geotextiles, and geocomposite sheet drains listed under Subsections
706.08, 714.01, 714.02 and 720.01 will be evaluated under Subsections
106.02 and 106.03.

Construction of mechanically stabilized earth wall will be evaluated
under Subsections 106.02 and 106.04.

Survey work will be evaluated under Section 152.

Concrete leveling pad will be evaluated under Section 601.

# Measurement

**255.08** Measure mechanically stabilized earth walls by the square
foot of front wall face. Structure excavation, select wall backfill,
wall backfill, wall facing fill, temporary shoring, drainage system, and
returns at the ends of each lift will not be measured for payment and
are considered incidental to the MSE walls.

Measure foundation fill under Section 208.

# Payment

**255.09** The accepted quantities, measured as provided above, will be
paid at the contract price per unit of measurement for the pay item
listed below that is shown in the bid schedule. Payment will be full
compensation for the work prescribed in this Section. See Subsection
109.05.

Payment at the unit bid price for the Section 255 pay items included in
the bid schedule is full compensation for wall construction to a depth
not exceeding 5 feet below the lowest elevation shown on the plans for
each MSE wall structure. MSE wall construction includes structure
excavation, structural backfill, wall elements, and all other costs
associated with the wall installation. When the depth of the footing
below the lowest elevation shown on the plans for each MSE wall exceeds
5 feet, either the Contractor or the CO may request an equitable price
adjustment for the depth in excess of 5 feet. There will be no equitable
adjustment when the depth of the footing does not exceed 5 feet below
the elevation shown in the plans; however, all work constructed will be
measured for payment.

**Table 255-7**

**Sampling and Testing Requirements**

+------+-------+---------+-----------+--------+------+----+------+
| **   | *     | **P     | **Test    | ##     | **P  | *  | **R  |
| Mate | *Type | roperty | Methods   | Sampli | oint | *S | epor |
| rial | of    | or      | or        | ng Fre | of   | pl | ting |
| or   | Ac    | Ch      | Specifi   | quency | Sa   | it | Ti   |
| P    | cepta | aracter | cations** |        | mpli | Sa | me** |
| rodu | nce** | istic** |           |        | ng** | mp |      |
| ct** |       |         |           |        |      | le |      |
|      | *     |         |           |        |      | ** |      |
|      | *(Sub |         |           |        |      |    |      |
|      | secti |         |           |        |      |    |      |
|      | on)** |         |           |        |      |    |      |
+------+-------+---------+-----------+--------+------+----+------+
| Back | Me    | Classif | AASHTO    | 1 per  | So   | Y  | Be   |
| fill | asure | ication | M145      | soil   | urce | es | fore |
|      | and   |         |           | type   | of   |    | u    |
|      | t     |         |           |        | mate |    | sing |
|      | ested |         |           |        | rial |    | in   |
|      | for   |         |           |        |      |    | work |
|      | c     |         |           |        |      |    |      |
|      | onfor |         |           |        |      |    |      |
|      | mance |         |           |        |      |    |      |
|      |       |         |           |        |      |    |      |
|      | (10   |         |           |        |      |    |      |
|      | 6.04) |         |           |        |      |    |      |
+------+-------+---------+-----------+--------+------+----+------+
|      |       | Gr      | AASHTO    | 1 per  | So   | Y  | Be   |
|      |       | adation | T27 & T11 | soil   | urce | es | fore |
|      |       |         |           | type   | of   |    | u    |
|      |       |         |           |        | mate |    | sing |
|      |       |         |           |        | rial |    | in   |
|      |       |         |           |        |      |    | work |
+------+-------+---------+-----------+--------+------+----+------+
|      |       | M       | AASHTO T  | 1 per  | So   | Y  | Be   |
|      |       | oisture | 180       | soil   | urce | es | fore |
|      |       | density | Method D  | type   | of   |    | u    |
|      |       |         | ^(1)^, or |        | mate |    | sing |
|      |       |         | AASHTO    |        | rial |    | in   |
|      |       |         | T99,      |        |      |    | work |
|      |       |         | Method C  |        |      |    |      |
|      |       |         | ^(1)^     |        |      |    |      |
+------+-------+---------+-----------+--------+------+----+------+
|      |       | Com     | AASHTO T  | 2 per  | In   | \  | Be   |
|      |       | paction | 310 or    | lift   | p    | -\ | fore |
|      |       |         | other     |        | lace | -- | u    |
|      |       |         | approved  |        |      |    | sing |
|      |       |         | p         |        |      |    | in   |
|      |       |         | rocedures |        |      |    | work |
+------+-------+---------+-----------+--------+------+----+------+

^(1)^ A minimum of five points per proctor.