Attachment B-2 - ODFW Clackamas Hatchery Siphon Modifications_April 2025.pdf

Table of Contents �

00 01 10 - 1

SECTION 00 01 10 � TABLE OF CONTENTS

CLACKAMAS HATCHERY SIPHON MODIFICATIONS

TECHNICAL SPECIFICATIONS

Division 00 � Table of Contents

Section 00 01 10 � Table of Contents

Division 31 � Earthwork

Section 31 05 16 � Aggregates for Earthwork Section 31 23 17 � Trenching Section 31 23 24 � Flowable Fill

Aggregates for Earthwork �

31 05 16 - 1

SECTION 31 05 16 - MATERIALS FOR EARTHWORK

PART 1 GENERAL

1.1 SUMMARY

A. This Section includes a range of coarse and fine aggregate and core materials intended to be referenced by other Sections, generally for fill and grading purposes. Materials are indicated by "Type" to assist in referencing from other Sections and in Drawing notes.

1.2 REFERENCES

A. American Association of State Highway and Transportation Officials:

1. AASHTO M147 - Standard Specification for Materials for Aggregate and Soil-Aggregate

Subbase, Base and Surface Courses

2. AASHTO T27 - Sieve Analysis of Fine and Coarse Aggregates

3. AASHTO T99 - Standard Specification for Moisture-Density Relations of Soils Using a 2.5-kg

(5.5-lb) Rammer and a 305-mm (12-in.) Drop

4. AASHTO TP61 - Standard Method of Test for Determining the Percentage of Fracture in

Coarse Aggregate

B. ASTM International (ASTM):

1. ASTM C136 - Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates

2. ASTM D698 - Standard Test Method for Laboratory Compaction Characteristics of Soil

Using Standard Effort (12,400 ft-lbf/ft3 (600 kN-m/m3))

3. ASTM D2487 - Standard Classification of Soils for Engineering Purposes (Unified Soil

Classification System)

4. ASTM D4318 - Standard Test Method for Liquid Limit, Plastic Limit, and Plasticity Index of

Soils

5. ASTM D6938 - Standard Test Method for In-Place Density and Water Content of Soil and

Soil-Aggregate by Nuclear Methods (Shallow Depth)

1.3 SUBMITTALS

A. Materials Source: Submit name of imported materials suppliers.

B. Manufacturer's Certificate: Certify Products meet or exceed specified requirements.

C. Results of aggregate sieve analysis and standard proctor tests for all granular material.

D. Submit results of Atterberg Limits and grain size analysis for Imported Core and Existing Core material.

31 05 16 - 2

E. Submit results of grain size analysis for on-site Terrace Deposits.

1.4 QUALITY ASSURANCE

A. Furnish each aggregate material from single source throughout the Work.

B. Aggregate Testing:

1. Aggregate sampling and testing to be completed by an independent laboratory approved by the Engineer.

2. The frequency of testing shall be determined by the Engineer.

3. All aggregate testing shall be paid for by the Contractor.

C. Compaction Tests:

1. Maximum density at optimum moisture content determined by ASTM D698.

2. In-place density in accordance with Nuclear Testing Method, ASTM D6938.

D. Aggregate Classification: All imported materials shall be classified in accordance with ASTM

D2487.

PART 2 PRODUCTS

2.1 COARSE AGGREGATE MATERIALS

A. Coarse Aggregate Type A1, Dense-Graded Aggregate: Crushed rock with ¾-inch-0, 1-inch-0, 1-

1/2-inch-0, 2-inch-0 and 2-1/2-inch-0 gradation as shown on the Drawings and meeting the requirements provided below.

1. Grading - Dense-graded base aggregate shall be crushed rock, including sand. Uniformly grade the aggregates from coarse to fine.

2. Sieve analysis shall be determined according to AASHTO T27.

3. The aggregates shall conform to one of the grading requirements Table 31 05 16-A below.

31 05 16 - 3

Table 31 05 16-A

Grading Requirements for Dense-Graded Aggregate

Separated Sizes

Percent Passing (by weight)

Sieve Size

2-1/2" - 0 2" - 0 1-1/2" - 0 1" - 0 3/4" - 0

3� 100

2-1/2� 95 - 100 100

2� - 95 - 100 100

1-1/2" - - 95 - 100 100

1-1/4� 55 - 75 - - -

1� - 55 - 75 - 90 - 100 100

3/4" - - 55 - 75 - 90 - 100

1/2" - - - 55 - 75 -

3/8� - - - - 55 - 75

1/4" 30 - 45 30 - 45 35 - 50 40 - 55 40 - 60

No. 4* - - - - -

No. 10 1 1 1 1 1

1 Of the fraction passing the 1/4-inch sieve, 40 percent to 60 percent shall pass the No. 10 sieve.

* Report percent passing sieve when no grading requirements are listed.

B. Coarse Aggregate Type A2, Granular Drain Backfill Material: Crushed or uncrushed rock or gravel as shown on the Drawings.

1. Material shall be clean and free draining.

2. Sieve analysis shall be according to AASHTO T27.

3. Grading: Meeting the gradation requirements provided in Table 31 05 16-B below.

Table 31 05 16-B

Grading Requirements for Granular Drain Backfill Material

Separated Sizes

Percent Passing (by weight)

Sieve Size Separated Sizes

1-1/2-inch � 3/4-inch

Separated Sizes

3/4-inch � 1/2-inch

2-inch 100

1-1/2-inch 90 - 100

1-inch 20 - 55 100

3/4-inch 0 - 15 85 - 100

1/2-inch - 0 - 15

3/8-inch 0 - 5 -

31 05 16 - 4

2.2 FILTER SAND (ASTM C-33)

A. Filter Sand: Sand material shall consist of granular material, naturally produced, or produced from crushed gravel, or dredge sand that is reasonably free of organic material, mica, clay, fly ash, and other deleterious material. Sand shall consist of ASTM C-33 concrete sand or approved alternate source meeting the gradations of Table 31 05 16-C below. The FERC will need to review and accept the filter gradation prior to placement.

Table 31 05 16-C

Grading Requirements for Filter Sand

Sieve Size Percent Passing

1-inch 100

3/8-inch 100

#4 90 - 100

#8 60 - 100

#16 40 - 100

#30 20 - 80

#50 5 - 40

#100 0 - 15

#200 0 - 5

2.3 CORE MATERIAL

A. Existing Core Material: Existing core material shall be excavated and replaced in kind. Existing core material shall generally meet the requirements of Imported Core Material below. A portion of the existing core material may be contaminated by adjacent embankment shell granular material and may be unsuitable for reuse as core material.

B. Testing of Existing Core Material: Collect representative samples of the Existing Core Material at locations approved by the Engineer for laboratory testing to determine filter compatibility of proposed Filter Sand material. Two to three representative samples of Core Material are anticipated.

a. Avoid contamination of Core Material soils during excavation.

b. Perform a particle size analysis in accordance with ASTM D422 for each collected sample.

c. Perform Atterberg limits tests in accordance with ASTM D4318 for each collected sample.

d. Provide test results to Engineer for review and approval prior to starting excavation of

Section A.

31 05 16 - 5

C. Imported Core Material: Imported core material shall consist of fine-grained fill that is reasonably free of excess moisture, roots, muck, sod, organic matter, gravel, cobbles or other deleterious material. Imported core material shall meet the following gradation:

Table 31 05 16-C

Grading Requirements for Core Material

Sieve Size Percent Passing

#4 100

#20 95 - 100

#40 90 � 1001

#200 50 � 100 1 The portion of the fill passing the No. 40 sieve shall have a plasticity index (PI) between 8 and

40.

2.4 EXISTING ON-SITE TERRACE DEPOSITS

A. Testing on-site Terrace Deposits: Collect representative samples of the Terrace Deposit material at locations approved by the Engineer for laboratory testing to determine filter compatibility of proposed Filter Sand material. Two to three representative samples of on-site

Terrace Deposits are anticipated.

a. Perform a particle size analysis in accordance with ASTM C136 for each collected sample.

b. Provide test results to Engineer for review and approval prior to starting excavation of

Section A.

2.5 SOURCE QUALITY CONTROL

A. Coarse Aggregate Material - Testing and Analysis: Perform in accordance with ASTM C136 and

ASTM D698.

B. Filter Sand - Testing and Analysis: Perform in accordance with ASTM C136 and ASTM D698.

C. Core Material - Testing and Analysis: Perform in accordance with ASTM D422 and ASTM D4318.

D. On-Site Terrace Deposits � Testing and Analysis: Perform in accordance with ASTM C136 and

ASTM D698.

E. When tests indicate materials do not meet specified requirements, change material and retest.

Additional testing shall be completed and paid for by the Contractor with no reimbursement by the Owner.

31 05 16 - 6

PART 3 EXECUTION

3.1 STOCKPILING

A. Stockpile materials imported to site at locations as approved by Engineer for redistribution as specified.

B. Separate different aggregate materials with dividers or stockpile individually to prevent mixing.

C. Prevent intermixing of aggregate types or contamination.

D. Direct surface water away from stockpile site to prevent erosion or deterioration of materials.

1. Grade surface of stockpiles to prevent ponding of water.

2. Cover stockpiles to minimize the infiltration of water.

3.2 STOCKPILE CLEANUP

A. Remove stockpile, leave area in clean and neat condition. Grade site surface to prevent free standing surface water.

B. When borrow area is indicated, leave area in clean and neat condition. Grade site surface to prevent free standing surface water.

END OF SECTION

Trenching �

31 23 17 - 1

SECTION 31 23 17 - TRENCHING

PART 1 GENERAL

1.1 SUMMARY

A. This Section includes the requirements for excavation and backfill of all utilities, including installation of pipe bedding, pipe zone backfill, trench backfill, filter diaphragm, core backfill, and related Work as shown on the Drawings and as specified.

1.2 REFERENCES

A. American Association of State Highway and Transportation Officials:

1. AASHTO T99 - Standard Specification for Moisture-Density Relations of Soils Using a 2.5-kg

(5.5-lb) Rammer and a 305-mm (12-in.) Drop

B. ASTM International (ASTM):

1. ASTM C403 - Standard Test Method for Time of Setting of Concrete Mixtures by

Penetration Resistance

2. ASTM D698 - Standard Test Method for Laboratory Compaction Characteristics of Soil

Using Standard Effort (12,400 ft-lbf/ft3 (600 kN-m/m3))

3. ASTM D6938 - Standard Test Method for In-Place Density and Water Content of Soil and

Soil-Aggregate by Nuclear Methods (Shallow Depth)

4. ASTM D3017 - Standard Test Method for Water Content of Soil and Rock in Place by

Nuclear Methods (Shallow Depth)

5. D4832, Standard Test Method for Preparation and Testing of Controlled Low Strength

Material (CLSM) Test Cylinders

1.3 DEFINITIONS

A. Controlled Low Strength Material (CLSM): Also referred to as Flowable Fill. Lean cement concrete fill. A self-compacting, cementitious material.

B. Flexible Pipe: For the purposes of these Specifications, tubing between 1/2-inch and 4-inch diameter constructed of polyvinyl chloride (PVC) and high-density polyethylene (HDPE) are considered flexible pipes. HDPE piping 4 inches in diameter and larger is also considered flexible pipe.

C. Geosynthetics: Geotextiles, geogrids, geomembranes, and drainage composite materials.

D. Imported Material: Materials obtained from sources offsite, suitable for specified use.

E. Lift: Loose (uncompacted) layer of material.

F. Obstructions: Items which may be encountered during utility and vault trenching which do not require replacement.

31 23 17 - 2

G. Optimum Moisture Content:

1. Determined in accordance with ASTM Standard specified to determine maximum dry density for relative compaction.

2. Determine field moisture content on basis of fraction passing 3/4-inch sieve.

H. Pipe Bedding: Trench backfill zone for full trench width which extends from the bottom outside surface of the pipe to a minimum of 6 inches below the bottom outside surface of pipe, conduit, cable, or duct bank to the trench foundation so as to uniformly support the barrel of the pipe.

I. Pipe Zone: Trench backfill zone for full trench width which extends from the bottom outside surface of the pipe to a minimum of 12 inches above the top outside surface of pipe, conduit, cable, or duct bank.

J. Pipe Bedding, Pipe Zone, Core Material, and Trench Backfill Classifications:

1. Class A: Backfill with suitable native or imported material that is approved to meet the characteristics required for the specific surface loading or other criteria of the backfill zone.

2. Class B: Backfill with imported granular material consisting of gravel or crushed rock meeting the requirements of this Section and Coarse Aggregate Type A1 as specified in

Section 31 05 16, Materials for Earthwork; typical designated size shall be 1-inch-0 or 3/4-inch-0.

3. Class C: Backfill with Filter Sand, as specified in Section 31 05 16, Materials for Earthwork.

4. Class D: Backfill with approved pit run or bar run material, well-graded from coarse to fine;

maximum dimension shall be 3 inches.

5. Class E: Backfill with CLSM. See Section 31 23 24, Flowable Fill.

6. Class F: Backfill with in-place core material or imported core material that is approved to meet characteristics for core material as specified in Section 31 05 16, Materials for

Earthwork.

K. Pothole Excavations: Removal and replacement of all materials via coring, vacuum extraction, or similar method for the purposes of locating an underground utility and to investigate underground conditions.

L. Prepared Trench Bottom: The bottom of the trench on which the pipe bedding is to lie, and which provides support for the pipe.

M. Relative Compaction: Ratio, in percent, of as-compacted field dry density to laboratory maximum dry density as determined in accordance with ASTM Standards.

N. Rigid Pipe: For the purposes of these Specifications, pipe constructed of PVC, ductile iron, steel, concrete, and clay pipes are considered rigid pipes.

O. Sewer, Pipes, and Mains: Conduits of circular or other geometric shapes, used to convey liquids or gases, or other material.

31 23 17 - 3

P. Trench Backfill: Trench backfill zone for full trench width extending from the top of the pipe zone to pavement base rock, ground surface, or other surface material.

Q. Trench Stabilization: Removal of unsuitable material in the bottom of a trench and replacement with specified material for support of a pipe, main, conduit, structure, or appurtenances.

R. Utility: Any buried pipe, duct, conduit, or cable.

S. Well-Graded: A mixture of particle sizes with no specific concentration or lack thereof of one or more sizes that, when compacted, produces a strong and relatively incompressible soil mass free from detrimental voids.

1.4 SUBMITTALS

A. Imported Materials:

1. Materials Source: Submit name and location of imported fill materials suppliers.

2. Manufacturer's Certificate: Certify Products meet or exceed specified requirements.

3. Submit results of aggregate sieve analysis and standard proctor test for granular material.

4. Submit results of Atterberg Limits and grain size analysis for Imported Core material.

B. CLSM: Mix designs in accordance with Submittal requirements of Section 31 23 24, Flowable

Fill.

PART 2 PRODUCTS

2.1 FILL MATERIALS

A. Imported Granular Fill: Coarse Aggregate Type A1, Dense-Graded Aggregate with gradation as shown in the Drawings and specified in Section 31 05 16, Materials for Earthwork.

B. Concrete:

1. Lean concrete as specified in Section 31 23 24, Flowable Fill, with compressive strength of

100 pounds per square inch (psi).

C. Sand: As specified in Section 31 05 16, Materials for Earthwork.

D. Core Material: As specified in Section 31 05 16, Materials for Earthwork.

E. Imported Core Material: As specified in Section 31 05 16, Materials for Earthwork.

PART 3 EXECUTION

3.1 PREPARATION

A. Call Local Utility Line Information service at 1-800-332-2344 not less than three working days before performing Work.

31 23 17 - 4

1. Request underground utilities to be located and marked within and surrounding construction areas.

2. Coordinate with and notify utility companies should it be necessary to remove or relocate facilities.

3. Maintain and protect above and below grade utilities indicated to remain.

B. Identify required lines, levels, contours, and datum locations.

C. Drawings and/or Specifications cover and govern replacement and restoration of foreseeable damage.

D. Potholing / Exploratory Test Pits: Dig such exploratory test pits and perform potholing as may be necessary in advance of trenching to determine the exact location and elevation of subsurface structures, pipelines, duct banks, conduits, and other obstructions which are likely to be encountered or need to be connected to and shall make acceptable provision for their protection, support, and maintenance of their continued operation.

E. Paved or Surfaced Streets:

1. Wherever paved or surfaced streets are cut, saw wheel, or approved cutting devices shall be used.

2. Any cut or broken pavement shall be removed from site during excavation.

F. Traffic:

1. Maintain street traffic at all times as required by the Drawings and as specified herein.

2. Erect and maintain barricades, warning signs, traffic cones, and other safety devices during construction in accordance with the latest edition of Manual of Uniform Traffic Control

Devices (MUTCD), Part 6, to protect the traveling public in any area applicable.

3.2 PROTECTION

A. Existing Facilities:

1. It is the intent of these specifications that all streets, structure, and utilities be left in a condition equal to or better than original condition at the completion of the Project.

2. Where damage occurs, and cannot be repaired or replaced, the Contractor shall purchase and install new material to the satisfaction to the Engineer.

3. Drawings and/or specifications cover and govern replacement and restoration of foreseeable damage.

B. Trench Protection:

1. Provide the materials, labor, and equipment necessary to protect trenches at all times.

2. Trench protection shall provide safe working conditions in the trench and protect the

Work, existing property, utilities, pavement, etc.

31 23 17 - 5

3. The method of protection shall be according to the Contractor�s design.

4. The Contractor may elect to use a combination of shoring, overbreak, tunneling, boring, sliding trench shields, or other methods of accomplishing the work provided the method meets the approval of all applicable local, state, and federal safety codes.

5. Damages resulting from improper shoring, improper removal of shoring, or from failure to shore shall be the sole responsibility of the Contractor.

3.3 LINES AND GRADES

A. Trench excavation for piping, utility vaults, and other utilities shall be performed to the alignment and grade as indicated on the Drawings.

B. The Engineer reserves right to make changes in lines, grades, and depths of utilities when changes are required for Project conditions.

C. Changes in the grade and horizontal alignment of the pipeline as shown on the Drawings or as provided elsewhere in the Specifications may be necessary due to unanticipated interferences or other reasons.

1. No additional compensation will be allowed the Contractor for changes in horizontal alignment.

2. No additional compensation will be allowed for changes in grade which require additional depth of trench excavation and backfill up to 2 feet from those shown on the Drawings.

D. Use laser-beam instrument with qualified operator to establish lines and grades.

3.4 INTERFERING ROADWAYS AND STRUCTURES

A. Remove, replace and/or repair any damage done during trenching activities to fences, buildings, cultivated fields, drainage crossings, and any other properties without additional compensation from the Owner.

1. Replace or repair these structures to a condition as good as or better than their pre-construction condition prior to commencing work in the area.

B. Paved Roadways:

1. Where paved roadways are cut as part of trenching activities, Class D trench backfill will be required to the bottom of pavement base.

2. New pavement shall be equal to or better than the existing paved surface.

3. New surface shall not deviate by more than 1/4-inch from the existing finish elevation.

C. Existing Structures:

1. If existing structures are encountered as part of trenching activities which will prevent construction and are not adequately shown on the Drawings, the Contractor shall notify the Engineer before continuing with the Work.

31 23 17 - 6

2. The Engineer may make such field revisions to the utility alignment as necessary to avoid conflict with the existing conditions.

3. The cost of waiting or �down time� during such field revisions shall be borne by the

Contractor without additional cost to the Owner or liability to the Engineer.

4. If the Contractor fails to notify the Engineer when a conflict of this nature is encountered, but proceeds with construction despite this interference, the Contractor shall do so at the

Contractor�s own risk with no additional payment.

3.5 TRENCHING

A. Excavate subsoil as required for construction of utilities to elevations shown on the Drawings.

B. Open Trench Limit:

1. Do not advance open trench beyond the distance which will be backfilled and compacted or covered the same day.

2. Cover or backfill excavations at the end of each day.

3. If the trench is not backfilled at the end of each working day:

a. Provide means to prevent caving of excavation sides, as necessary, during non-working hours.

b. Cover the excavation with a system as needed to provide public safety and prevention of entry during non-working hours.

4. New trenching shall not be started when earlier trenches need backfilling, or the surfaces of streets or other areas need to be restored to a safe and proper condition.

C. Trench Sequencing:

1. The contractor may elect to trench and install HDPE pipe within Trench Sections A, B, and

C as shown on the Drawings in any order they select.

2. Trench Section A (Embankment Section) must be trenched and backfilled in one continuous operation.

D. Before beginning Trench Section A, collect representative samples of the existing Core Material at locations approved by the Engineer for laboratory testing to determine filter compatibility of proposed Filter Sand material as specified in Section 31 05 16, Materials for Earthwork. Two to three representative samples of Core Material are anticipated for testing.Utility Crossings:

Avoid horizontal and vertical conflicts with existing utilities.

1. Perform excavation within 24 inches of existing utility service in accordance with utility�s requirements.

2. Vertical clearance between the new pipe and existing utilities shall be 12 inches minimum, unless otherwise noted on the Drawings.

31 23 17 - 7

3. Where existing utility lines are damaged or broken during trenching activities, the utility shall be repaired or replaced. For water or sewer bearing lines, care being taken to insure a smooth flow line and absolutely no leakage at the new joints.

4. All expenses involved in the repair or replacement of leaking or broken utility lines that have occurred due to the Contractor�s operations shall be borne by the Contractor, and the amount thereof shall be absorbed in the unit prices of its bid.

E. Excavate trenches to width and depth as indicated on Drawings. No additional payment will be provided for trenching activities beyond dimensions shown on the Drawings.

1. Excavation for trenches in which pipelines are to be installed shall provide adequate space for workers to place and joint the pipe properly and safely, but in every case the trench shall be kept to a minimum width.

2. For pipe or utility vaults to have bedding material, excavate to a depth of 6 inches below the bottom of the pipe or utility vault. Care shall be taken not to excavate below depths required.

3. Excavation slopes for Trench Section A shall be no steeper than 2H:1V as shown on the

Drawings.

4. If over digging occurs outside of Trench Section A, the trench bottom shall be filled to proposed subgrade elevation with compacted bedding material.

5. If over digging occurs within Trench Section A, the trench bottom shall be filled to proposed subgrade elevation using Core Material or Imported Core Material or as described in

Section 3.5.H if terrace gravels are exposed.

F. Remove water or materials that interfere with Work.

1. The trench at all times shall be kept free from water to facilitate fine grading, the proper laying and joining of pipe, and prevention of damage to completed joints.

2. Adequate pumping equipment shall be provided to handle and dispose of the water without damage to adjacent property.

3. Water in the trench shall not be allowed to flow through the pipe while construction work is in progress unless special permission to do so has been given by the Engineer.

4. The costs associated with the removal of water and materials noted above will be considered incidental to trench excavation and backfill.

G. Over-excavation for Unsuitable Trench Foundation Conditions outside of Trench Section A shown on the Drawings:

1. Cross-sectional dimensions and depths of excavations shown on the Drawings shall be subject to such changes as may be found necessary by the Engineer to secure foundations free from soft, weathered, shattered, and loose material or other objectionable materials.

2. Unsuitable materials shall be removed and replaced only as directed in writing by Engineer.

31 23 17 - 8

3. Unsuitable materials encountered shall be removed and replaced with Coarse Aggregate

Type A1, 2-1/2-inch � 0 gradation, as specified in Table 31 05 16-A of Section 31 05 16, Materials for Earthwork. All material placed shall be compacted to 95 percent of maximum dry density.

4. Install nonwoven geotextile under trench stabilization material, over the soft or yielding excavated surface.

a. Install the nonwoven geotextile ahead of placement of the trench stabilization material, continuously along the excavation bottom and centered on the pipe centerline.

b. Use nonwoven geotextile width equal to the pipe diameter plus 2 feet.

c. Place laps or splices in the geotextile in the direction of the pipe laying.

H. Unsuitable Trench Foundation Conditions beneath the core within Trench Section A shown on the Drawings:

1. Cross-sectional dimensions and depths of excavations shown on the Drawings shall be subject to such changes as may be found necessary by the Engineer to secure embankment core material in direct contact with open terrace gravel foundation soils.

2. The proposed Filter Diaphragm trench excavation underlying the core as shown on the

Drawings may be used as an indicator for the presence of terrace gravels beneath the core.

3. Unsuitable materials shall be removed and replaced only as directed in writing by Engineer.

a. If terrace gravels are present beneath a continuous section of the core, unsuitable terrace gravels encountered shall be removed and replaced with a minimum 6-inch thick CLSM base slab, as specified in Section 31 23 24, Flowable Fill.

b. If terrace gravels are present beneath isolated areas of the core, unsuitable terrace gravels encountered shall be removed and replaced with a minimum 12-inch-thick layer of Filter Sand, as specified in Section 31 05 16, Materials for Earthwork. All Filter

Sand material placed shall be compacted to 95 percent of maximum dry density of a one point standard proctor (air dried sample) per Section 3.7.G.

I. Trim excavation. Hand trim for bell and spigot pipe joints. Remove loose matter.

J. Excavated material shall be placed at locations and in such a manner that it does not create a hazard to pedestrian or vehicular traffic or interfere with the function of existing drainage facilities or system operation.

K. Remove excess subsoil not intended for reuse from site.

3.6 SHEETING AND SHORING

A. Sheet, shore, and brace excavations to prevent danger to persons, new and existing structures, and adjacent and neighboring properties and to prevent caving, erosion, settlement, and loss of surrounding subsoil.

31 23 17 - 9

B. Support trenches more than 5 feet deep excavated through unstable, loose, or soft material.

Provide sheeting, shoring, bracing, or other protection to maintain stability of excavation.

C. Repair damage caused by failure of the sheeting, shoring, or bracing and for settlement of filled excavations or adjacent soil.

D. Repair damage to new and existing Work from settlement, water or earth pressure or other causes resulting from inadequate sheeting, shoring, or bracing.

E. Design sheeting and shoring to be removed at completion of excavation work, unless shown otherwise on the Drawings.

3.7 COMPACTION

A. Testing will be required to show specified densities of compacted backfill are being achieved by the Contractor�s compaction methods (Section 3.10).

B. Moisture Control (Class A and B):

1. Moisture condition backfill material to within 2 percent of optimum moisture content required for compaction throughout each lift of the fill.

2. Add moisture to granular backfill by sprinkling during compaction operation.

3. Compaction by ponding or jetting is not permitted.

C. Moisture Control (Class C):

1. Moisture condition Filter Sand material wet of optimum moisture content required for compaction throughout each lift of the fill. Filter Sand shall be thoroughly wetted immediately prior to compaction with equipment.

D. Moisture Control (Class F):

1. Moisture condition Core Material to 1 to 3 percent wet of optimum moisture content required for compaction throughout each lift of the fill.

E. Compact Class B backfill to 95 percent of maximum density. Outside of Trench Section A, compact Class A backfill to 90 percent of maximum density.

F. Compact core material within Trench Section A to 95 percent of maximum density.

G. Compact Filter Sand for the Filter Diaphragm to 95 percent of a one-point standard proctor test (ASTM D 698A) on a Filter Sand sample which is thoroughly air-dried prior to performing the test. Each lift of Filter Sand shall be compacted by approximately two passes using a vibratory plate compactor or smooth drum roller in dynamic mode. Compaction shall be observed by the Engineer. Care shall be taken not to over-compact the Filter Sand to prevent breakdown of material or lowering of hydraulic conductivity.

H. Compact all materials and areas that are not accessible for in-place density testing, as determined by the Engineer, in place by whatever equipment and method is practicable or specified, and as approved by the Engineer.

31 23 17 - 10

1. Perform compaction at such moisture content as is required to produce well-filled, dense, and firm material in place that will show no appreciable deflection or reaction under the compacting equipment.

3.8 BEDDING

A. All utility vaults, potable water pipe 4-inch nominal diameter and over, all steel pipe, all concrete sewer pipe, all plastic pipe, all pipe under existing or future structures or roadways, and any and all utilities at a depth greater than 6 feet shall be laid in pipe bedding material.

B. Unless otherwise noted on the Drawings, pipe, or conduit of less than 4-inch diameter, outside structure lines and at a depth of less than 6 feet shall be bedded in native material properly shaped as specified below, all as detailed on the Drawings.

C. Compacted bedding material shall be placed the full width of the excavated trench to a depth as shown on the trench detail included on the Drawings.

1. In lieu of a detail, the depth shall be 6 inches.

D. Spread the bedding smoothly over entire width of trench to the proper grade so that the pipe is uniformly supported along the barrel.

E. Hand grade and compact each lift to provide a firm, unyielding surface along the entire pipe length. For rigid pipe, compact to at least 90 percent relative compaction.

F. Excavate bell holes at each joint to permit proper assembly and inspection of the joint.

G. Check grade and correct irregularities in bedding material.

H. Center pipes horizontally in trench width.

3.9 BACKFILLING

A. Backfill trenches to contours and elevations with unfrozen fill materials.

B. Systematically backfill to allow maximum time for natural settlement. Do not backfill over porous, wet, frozen, or spongy subgrade surfaces.

C. Place fill material, with the exception of CLSM, in continuous layers and compact in 6- to 8-inch lifts.

1. Prevent pipe from moving either horizontally or vertically during placement and compaction of pipe zone material.

2. Where trenches are under existing or future structures, paved areas, road shoulders, driveways, or sidewalks, or where designated on the Drawings or specified elsewhere in these specifications, the trench backfill shall be Class B or Class E and pipe zone backfill shall be Class B or Class E.

3. Where trenches are outside existing or future structures, paved areas, road shoulders, driveways, or sidewalks, or where designated on plans or specified elsewhere, the trench backfill shall be Class A and pipe zone backfill in these areas shall be Class B.

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D. Employ placement method that does not disturb or damage nearby or adjacent foundation perimeter drainage or utilities in trench.

E. Do not use power-driven impact compactors to compact pipe zone material.

F. Backfill Immediately: All trenches and excavations shall be backfilled immediately after pipe or conduit is in approved condition to receive it and shall be carried to completion as rapidly as possible, unless otherwise directed by the Engineer.

G. Under no circumstances shall water be permitted to rise in open trenches after pipe has been placed.

H. Do not allow backfill material to free fall into the trench or allow heavy, sharp pieces of material to be placed as backfill until after at least 2 feet of backfill has been provided over the top of pipe.

I. Use hand compactors for compaction until at least 2 feet of backfill is placed over top of pipe.

Thoroughly tamp each lift, including area under haunches, with handheld tamping bars supplemented by �walking in� and slicing material under haunches with a shovel to ensure that voids are completely filled before placing each succeeding lift.

J. Placement of Filter Sand:

1. Place sand in lifts not exceeding 8 inches in uncompacted thickness.

2. Final Diaphragm Filter location will be determined in the field during construction based on soil conditions encountered. The Diaphragm Filter shall be placed downstream of the interface of core material and embankment shell material observed within the recent geotechnical explorations (Kleinschmidt, 2022). Filter Diaphragm shall be placed directly against the core at the same slope of the core, as shown on the Drawings and as approved by the Engineer.

3. The upper surface of the sand filter zone constructed concurrently with adjacent zones of core material shall be maintained at an elevation between 0 and 1 foot above the upper surface of adjacent core material.

K. Placement of CLSM:

1. Discharge from truck-mounted drum-type mixer into trench.

2. Place in lifts not exceeding 2 feet in thickness.

3. No compaction of CLSM is allowed.

4. Place CLSM at a 1H:10V or shallower slope adjacent to the HDPE pipe as indicated on the

Drawings within Trench Section A and B.

5. Use steel plates to protect the CLSM from traffic a minimum of 24 hours. After 24 hours, the CLSM may be paved, or opened to traffic until permanent surface restoration is completed if it has hardened sufficiently to prevent rutting.

L. Placement of core material:

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1. Core Material excavated and replaced in-kind within the embankment shall be placed at the base of the embankment. Any Imported Core Material needed shall be placed at the top of the core within the embankment section.

2. A portion of the existing core material may be contaminated by adjacent embankment shell granular material and may be unsuitable for reuse as core material. Care should be taken when excavating core material to avoid contamination.

M. New trenching shall not be started when earlier trenches need backfilling, or the surfaces of streets or other areas need to be restored to a safe and proper condition.

N. Do not leave trench open at end of working day.

3.10 FIELD QUALITY CONTROL

A. All testing and reporting shall be conducted and completed by an independent laboratory provided by the Contractor.

B. Obtain field samples of imported Filter Sand and Imported Core Material. Perform grain size analysis on the samples to confirm materials meet project specified gradations. Perform

Atterberg limits tests on Imported Core Material to confirm materials meet project specifications.

C. In-place compaction testing of pipeline backfill materials shall be performed at 2-foot elevation increments, one test per 200 lineal feet of pipeline trench as measured along pipe centerline.

A minimum of 3 compaction tests shall be performed on the filter diaphragm and core material

(each) with one of the tests on the first two feet of filter and core placed and compacted.

1. The Engineer may reduce the frequency when satisfied with method of compaction.

2. The Engineer may direct testing at a higher frequency at no additional cost to the Owner upon failure to obtain specified densities or if the Contractor changes compaction equipment or methods of compaction.

3. The Engineer shall determine all test locations.

D. Perform in place compaction tests in accordance with the following:

1. Density Tests: ASTM D6938

2. Moisture Tests: ASTM D3017

E. Subgrade Observation:

1. All subgrade beneath the core within Trench Section A shall be observed by the Engineer prior to placing backfill material.

F. When tests indicate Work does not meet specified requirements, remove Work, replace, and retest at the sole expense of the Contractor.

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3.11 SURFACE RESTORATION AND CLEANUP

A. Open Trenches: At the end of each workday, all open trenches shall be backfilled and all trenches within streets shall be temporarily paved or covered to the satisfaction of the

Engineer and the local permitting agency.

1. Temporary paving shall be replaced with permanent street paving at the completion of construction within street rights-of-way, or sooner, if deemed necessary by the Engineer.

2. No gravel-filled trenches shall be left open within the street right-of-way at the end of the workday.

B. Topsoil:

1. Where trenches cross lawns, garden areas, pastures, cultivated fields, or other areas on which reasonable topsoil conditions exist, remove the topsoil to the specified depth and place the material in a stockpile.

2. Topsoil shall not be mixed with other excavated material.

3. After the trench has been backfilled, the topsoil shall be replaced.

C. Clean up and remove all excess materials, construction materials, debris from construction, etc. Replace or repair any fences, mailboxes, signs, landscaping, or other facilities removed or damaged during construction. Replace all lawns, topsoil, shrubbery, flowers, etc., damaged or removed during construction. The Contractor shall be responsible for seeing that lawns, shrubs, etc. remain alive and leave premises in condition equal to original condition before construction.

Flowable Fill �

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SECTION 31 23 24 - FLOWABLE FILL

PART 1 GENERAL

1.1 SUMMARY

A. This Section includes flowable lean concrete mix used for structure backfill, utility bedding and backfill and other subgrade Site Work. Applications also include filling abandoned structures and utilities that remain in place.

1.2 DEFINITIONS

A. Flowable Fill: Also referred to as Controlled Low Strength Material (CLSM) elsewhere in the

Specifications. Lean cement concrete fill.

B. Utility: Any buried pipe, duct, conduit, manhole, tank, or cable.

1.3 REFERENCE STANDARDS

A. ASTM International (ASTM):

1. ASTM C33 - Standard Specification for Concrete Aggregates

2. ASTM C94 - Standard Specification for Ready-Mixed Concrete

3. ASTM C150 - Standard Specification for Portland Cement

4. ASTM C260 - Standard Specification for Air-Entraining Admixtures for Concrete

5. ASTM C403 - Standard Test Method for Time of Setting of Concrete Mixtures by

Penetration Resistance

6. ASTM C494 - Standard Specification for Chemical Admixtures for Concrete

7. ASTM C618 - Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use as a Mineral Admixture in Concrete

8. ASTM C1017 - Standard Specification for Chemical Admixtures for Use in Producing Flowing

Concrete

9. ASTM C1040 - Standard Test Methods for Density of Unhardened and Hardened Concrete in Place by Nuclear Methods

10. ASTM D4832 - Standard Test Method for Preparation and Testing of Controlled Low

Strength Material (CLSM) Test Cylinders

1.4 SUBMITTALS

A. Manufacturer's Certificate: Certify that products meet or exceed specified requirements.

B. Field Quality-Control Submittals:

1. Mix Design:

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a. Furnish flowable fill mix design for each specified strength.

b. Furnish separate mix designs when admixtures are required for the following:

1) Flowable fill Work during hot and cold weather.

2) Air entrained flowable fill Work.

c. Identify design mix ingredients, proportions, properties, admixtures, and tests.

2. Furnish test results to certify flowable fill mix design properties meet or exceed specified requirements.

C. Delivery Tickets:

1. Furnish duplicate delivery tickets indicating actual materials delivered to Project Site.

1.5 QUALITY ASSURANCE

A. In-place testing of Flowable Fill: In accordance with ASTM C403.

B. Compressive testing of Flowable Fill: In accordance with ASTM D4832.

1.6 ENVIRONMENTAL REQUIREMENTS

A. Minimum Conditions: The following minimum conditions shall be met at time of flowable fill placement.

1. Do not install flowable fill during inclement weather.

2. Ambient temperature must be at least 34 degrees Fahrenheit (F) and rising.

3. Flowable fill shall be at 40 degrees F.

4. Subgrade on which flowable fill is to be placed shall be free of disturbed or soft material, debris, and water.

PART 2 PRODUCTS

2.1 FLOWABLE FILL

A. Flowable Fill:

1. Composed of cement, pozzolans, fine aggregate, water, and admixtures.

2. Low cement content.

3. Non-segregating, self-consolidating, free-flowing, and excavatable material which will result in a hardened, dense, non-settling fill.

4. Compressive strength at 28 days of 100 to 200 pounds per square inch (psi), if not otherwise shown on Drawings or specified.

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2.2 MATERIALS

A. Portland Cement: ASTM C150,.

B. Fine Aggregates: ASTM C33.

C. Water: Clean and not detrimental to concrete.

2.3 ADMIXTURES

A. Air Entrainment: ASTM C260.

B. Chemical Admixture: ASTM C494.

C. Fly Ash: ASTM C618 Class C or F, obtained from residue of electric generating plant using ground or powdered coal.

2.4 MIXES

A. Mix and deliver flowable fill according to ASTM C94, Option C.

B. Flowable Fill Design Mix:

ITEM PROPERTIES

Cement Content 75 to 100 lb/cu yd

Fly Ash Content None

Water Content As specified

Air Entrainment 5 to 35 percent

28-Day Compressive

Strength

Maximum 200 psi.

Unit Mass (Wet) 80 to 110 pcf

Temperature, Minimum at Point of

Delivery

50 degrees F (10 degrees C)

C. Provide water content in design mix to produce self-leveling, flowable fill material at time of placement.

D. Design mix air entrainment and unit mass are for laboratory design mix and source quality control only.

2.5 SOURCE QUALITY CONTROL

A. Test and analyze properties of flowable fill design mix and certify results for the following:

1. Design mix proportions by weight of each material.

2. Aggregate: ASTM C33 for material properties and gradation.

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3. Properties of plastic flowable fill design mix including:

a. Temperature

b. Slump

c. Air entrainment

d. Wet unit mass

e. Yield

f. Cement factor

4. Properties of hardened flowable fill design mix including:

a. Compressive strength at 1-day, 7 days, and 28 days. Report compressive strength of each specimen and average specimen compressive strength.

b. Unit mass for each specimen and average specimen unit mass at time of compressive strength testing.

B. Prepare delivery tickets containing the following information:

1. Project designation

2. Date

3. Time

4. Class and quantity of flowable fill

5. Actual batch proportions

6. Free moisture content of aggregate

7. Quantity of water withheld

PART 3 EXECUTION

3.1 PREPARATION

A. Support and restrain utilities to prevent movement and flotation during installation of flowable fill.

B. Protect structures and utilities from damage caused by hydraulic pressure of flowable fill before fill hardens.

C. Protect utilities and foundation drains to prevent intrusion of flowable fill.

3.2 INSTALLATION � FILL, BEDDING, AND BACKFILL

A. Place flowable fill by chute, pumping, or other methods as approved by Engineer.

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B. Place flowable fill in lifts to prevent lateral pressures from exceeding structural capacity of structures and utilities.

C. Place flowable fill evenly on both sides of utilities to maintain alignment.

D. Place flowable fill at a 1H:10V or shallower slope adjacent to the HDPE pipe as indicated on the

Drawings within Trench Section A and B.

E. Place flowable fill to elevations indicated on Drawings without vibration or other means of compaction.

3.3 FIELD QUALITY CONTROL

A. Perform inspection and testing according to ASTM C94.

1. Take samples for tests for every 100 cubic yards of flowable fill, or fraction thereof, installed each day.

2. Sample, prepare, and test four compressive strength test cylinders according to ASTM

D4832. Test one specimen at 3 days, one at 7 days, and two at 28 days.

3. Measure temperature at point of delivery when samples are prepared.

B. Further construction proceeding upon placed flowable fill will be permitted only after initial set is attained, as measured by ASTM C 403.

1. Perform in place penetration (density) tests using handheld penetrometer to measure penetration resistance of hardened flowable fill.

2. Perform tests at locations as directed by Engineer.

C. Defective Flowable Fill: The Engineer reserves the right to reject all flowable fill failing to meet the following test requirements or flowable fill delivered without the following documentation.

1. Test Requirements:

a. Minimum temperature at point of delivery.

b. Compressive strength requirements for each type of fill.

2. Documentation: Duplicate delivery tickets.

D. No traffic or construction equipment shall be allowed on flowable fill for at least 24 hours after placement.

3.4 CLEANING

A. Remove spilled and excess flowable fill from Project Site.

B. Restore facilities and Site areas damaged or contaminated by flowable fill installation to existing condition before installation.