W51DQV25A0002 Amd 003_Specs_31 00 00.pdf

Rio Puerto Nuevo Project Main Channel Design Supplemental Contract 3 San Juan, Puerto Rico

SECTION TABLE OF CONTENTS

DIVISION 31 - EARTHWORK

SECTION 31 00 00

EARTHWORK

PART 1 GENERAL

1.1 SCOPE

1.2 REFERENCES

1.3 DEFINITIONS

1.3.1 Satisfactory Materials

1.3.2 Unsatisfactory Materials

1.3.3 Cohesionless and Cohesive Materials

1.3.4 Degree of Compaction

1.3.5 Topsoil

1.3.6 Hard/Unyielding Materials

1.3.7 Unstable Material

1.3.8 Expansive Soils

1.4 SYSTEM DESCRIPTION

1.4.1 Classification of Excavation

1.4.2 Blasting

1.4.3 Water Control Plan

1.5 SUBMITTALS

1.6 IN-CHANNEL EXCAVATION RESTRICTIONS

1.6.1 Order of Work

1.6.2 Transportation of Material

1.7 APPROVED DISPOSAL SITE

PART 2 PRODUCTS

2.1 REQUIREMENTS FOR OFFSITE SOILS

2.2 GENERAL FILL MATERIAL

2.3 GRANULAR FILL MATERIALS

2.3.1 Select Fill Material

2.3.2 Structural Fill Material

2.4 UNDERWATER PLACEMENT GRANULAR MATERIAL

2.5 WALL DRAINAGE MATERIAL

2.6 BEDDING MATERIAL

2.7 UTILITY BEDDING AND BACKFILL

2.8 BURIED WARNING AND IDENTIFICATION TAPE

2.9 DETECTION WIRE FOR NON-METALLIC PIPING

2.10 MATERIAL FOR RIP-RAP

2.11 PIPE CASING

2.11.1 Utility Casing Pipe

2.11.2 Wood Supports

2.12 GEOTEXTILES

PART 3 EXECUTION

3.1 STRIPPING OF TOPSOIL

3.2 GENERAL EXCAVATION

SECTION 31 00 00 Page 1 W51DQV25RA002 Amendment 0003

3.2.1 Ditches, Gutters, and Channel Changes

3.2.2 Drainage Structures

3.2.3 Drainage

3.2.4 Dewatering

3.2.5 Trench Excavation Requirements

3.2.5.1 Bottom Preparation

3.2.5.2 Removal of Unyielding Material

3.2.5.3 Removal of Unstable Material

3.2.5.4 Excavation for Appurtenances

3.2.5.5 Jacking, Boring, and Tunneling

3.2.6 Underground Utilities

3.2.7 Structural Excavation

3.2.8 Drilled Shaft Wall Monitoring

3.3 IN-CHANNEL EXCAVATION PLAN

3.3.1 Required Depth

3.3.2 Structural Offsets

3.4 SELECTION OF BORROW MATERIAL

3.5 OPENING AND DRAINAGE OF EXCAVATION AND BORROW PITS

3.6 SHORING AND SHEETING

3.6.1 General Requirements

3.6.2 Contractor's Geotechnical Engineer

3.7 GRADING AREAS

3.8 GROUND SURFACE PREPARATION

3.9 UTILIZATION OF EXCAVATED MATERIALS

3.10 BURIED DETECTION WIRE

3.10.1 Buried Detection Wire

3.11 BACKFILLING AND COMPACTION

3.11.1 Trench Backfill

3.11.1.1 Replacement of Unyielding Material

3.11.1.2 Replacement of Unstable Material

3.11.1.3 Utility Bedding and Initial Backfill

3.11.1.4 Final Backfill

3.11.1.4.1 Roadways

3.11.2 Backfill for Appurtenances

3.12 SPECIAL REQUIREMENTS

3.12.1 Gas Distribution

3.12.2 Water Lines

3.12.3 Electrical Distribution System

3.13 ROADWAY EMBANKMENTS

3.13.1 Roadway Earth Embankments

3.14 SUBGRADE PREPARATION

3.14.1 Proof Rolling

3.14.2 Subgrade Preparation

3.14.2.1 Roadway Subgrade

3.14.3 Compaction

3.15 FINISHING

3.15.1 Subgrade and Embankments

3.15.2 Grading Around Structures

3.16 PLACING TOPSOIL

3.17 TESTING

3.17.1 Fill and Backfill Material Gradation

3.17.2 In-Place Density Tests

3.17.3 Moisture Contents

3.17.4 Optimum Moisture and Laboratory Maximum Density

3.17.5 Tolerance Tests for Subgrades

3.17.6 Displacement of Sewers

3.18 DISPOSITION OF SURPLUS MATERIAL

-- End of Section Table of Contents --

SECTION 31 00 00 Page 2

SECTION 31 00 00 Page 3

SECTION 31 00 00

EARTHWORK

PART 1 GENERAL

1.1 SCOPE

The work covered by this section consists of furnishing all labor, materials, and equipment, and performing excavation and filling activities required within the project limits and to define requirements of the various materials. Excavations covered under this specification include general excavation, structural excavations, and land-based methods of in-channel excavation, as well as, requirements for material designated for disposal within the La Chuleta upland disposal site or an approved disposal site. Refer to the Contract drawings for additional information related to the limits of material designated for offshore versus upland disposal. For requirements of barge-based operations and offshore disposal, see specification section 35 20 23 DREDGING.

The approved disposal sites are available for excavated material disposal and are being utilized by multiple projects and shall be managed by the Government. The Contractor is responsible for hauling operations including placing material in locations instructed by the Government. The Contractor is responsible to provide any necessary ramps, crawler, cranes or hoppers for barge tipping when offloading materials if delivered by barge to La Chuleta. The Government is responsible for, but not limited to, stormwater pollution prevention, containment, moisture control operations, dust control, and grading. Contractor shall coordinate with Government to ensure efficient hauling operations.

1.2 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS

(AASHTO)

AASHTO M 145 (1991; R 2012) Standard Specification for Classification of Soils and Soil-Aggregate Mixtures for Highway Construction Purposes

AASHTO T 180 (2017) Standard Method of Test for Moisture-Density Relations of Soils Using a 4.54-kg (10-lb) Rammer and a 457-mm (18-in.) Drop

AASHTO T 224 (2010) Standard Method of Test for Correction for Coarse Particles in the Soil Compaction Test

SECTION 31 00 00 Page 4

AMERICAN WATER WORKS ASSOCIATION (AWWA)

AWWA C600 (2017) Installation of Ductile-Iron Mains and Their Appurtenances

AMERICAN WOOD PROTECTION ASSOCIATION (AWPA)

AWPA P5 (2015) Standard for Waterborne Preservatives

ASTM INTERNATIONAL (ASTM)

ASTM A139/A139M (2016) Standard Specification for Electric-Fusion (ARC)-Welded Steel Pipe (NPS 4 and over)

ASTM A252 (2010) Standard Specification for Welded and Seamless Steel Pipe Piles

ASTM C33/C33M (2023) Standard Specification for Concrete Aggregates

ASTM C136/C136M (2019) Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates

ASTM D1140 (2017) Standard Test Methods for Determining the Amount of Material Finer than 75-µm (No. 200) Sieve in Soils by Washing

ASTM D1557 (2012; E 2015) Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft3) (2700 kN-m/m3)

ASTM D2216 (2019) Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass

ASTM D2434 (1968; R 2006) Permeability of Granular Soils (Constant Head)

ASTM D2487 (2017; E 2020) Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System)

ASTM D2974 (2020; E 2020) Moisture, Ash, and Organic Matter of Peat and Other Organic Soils

ASTM D4253 (2016; E 2019) Standard Test Methods for Maximum Index Density and Unit Weight of Soils Using a Vibratory Table

ASTM D4318 (2017; E 2018) Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils

ASTM D4972 (2018) Standard Test Methods for pH of

SECTION 31 00 00 Page 5

Soils

ASTM D5268 (2019) Topsoil Used for Landscaping Purposes

ASTM D6913/D6913M (2017) Standard Test Methods for Particle-Size Distribution (Gradation) of Soils Using Sieve Analysis

ASTM D6938 (2017a) Standard Test Method for In-Place Density and Water Content of Soil and Soil-Aggregate by Nuclear Methods (Shallow Depth)

U.S. ENVIRONMENTAL PROTECTION AGENCY (EPA)

EPA 600/4-79/020 (1983) Methods for Chemical Analysis of Water and Wastes

EPA SW-846.3-3 (1999, Third Edition, Update III-A) Test Methods for Evaluating Solid Waste:

Physical/Chemical Methods

COMMONWEALTH OF PUERTO RICO, DEPARTMENT OF TRANSPORTATION AND

PUBLIC WORKS (PRHTA)

PRHTA Specifications (2005) Standard Specifications for Road and Bridge Construction

Special Provisions, when applicable, are appended and included as an attachment to this specification section. Where PRHTA Specifications Section, and/or Special Provision(s) is cited that contains references to other PRHTA sections, they shall also form a part of this specification to the extent referenced. Where reference is made to "Highway Authority" or "Authority's Representative" in PRHTA Specifications shall mean "Government" or "Contracting Officer" as defined in the Contract Documents. Where PRHTA Specifications refer to the "Engineer", "Engineer of Tests", or "Division of Tests" it shall be understood to mean the "Contracting Officer" as stated in the Contract Documents. In case of conflict between the PRHTA specifications and the Specifications in this Section that follows, the Specifications in this Section shall govern.

Paragraphs titled "Method of Measurement" and "Basis of Payment" of referenced PRHTA Specifications shall not apply.

1.3 DEFINITIONS

1.3.1 Satisfactory Materials

Satisfactory materials are onsite or imported materials that are shown to meet the requirements for fill, backfill, and bedding materials provided in Part 2 of this Specification through applicable laboratory testing.

1.3.2 Unsatisfactory Materials

Unsatisfactory materials are those which do not comply with the requirements for fill, backfill, and bedding material provided in Part 2 of this specification and the following requirements. Unsatisfactory materials also include materials that consist of or contain man-made

SECTION 31 00 00 Page 6 fills; trash; refuse; backfills from previous construction; roots, organic matter, stones larger than 3 inches in any dimension, or other deleterious material. Notify the Contracting Officer when encountering any contaminated materials.

1.3.3 Cohesionless and Cohesive Materials

Cohesionless materials include materials classified in ASTM D2487 as GW, GP, SW, and SP. Cohesive materials include materials classified as GC, SC, ML, CL, MH, and CH. Materials classified as GM and SM will be identified as cohesionless only when the fines are non-plastic. Perform testing, required for classifying materials, in accordance with ASTM D4318, ASTM C136/C136M and ASTM D1140.

1.3.4 Degree of Compaction

Degree of compaction required, except as noted in the second sentence, is expressed as a percentage of the maximum density obtained by the test procedure presented in ASTM D1557, AASHTO T 180 , or ASTM D4253 abbreviated as a percent of laboratory maximum density. ASTM D1557 and AASHTO T 180 are used interchangeably in this specification. The maximum density test for soils used shall be selected based on the proportion of material retained on the ¾-inch sieve. ASTM D1557 shall be used for maximum density determinations if soils have 30 percent or less by weight of their particles retained on the 3/4 inch sieve. If soils have more than 30 percent by weight of their particles retained on the 3/4 inch sieve, the maximum density shall be determined in accordance with AASHTO T 180 , Method D and the reported maximum density shall be corrected in accordance with AASHTO T 224 . To maintain the same percentage of coarse material, use the "remove and replace" procedure as described in NOTE 8 of Paragraph

7.2 in AASHTO T 180 . ASTM D4253 shall be used for maximum density determinations of coarse aggregates as defined by ASTM C33/C33M.

1.3.5 Topsoil

Material suitable for topsoil is defined as: Natural, friable soil representative of productive, well-drained soils in the area, free of subsoil, stumps, rocks larger than one inch diameter, brush, weeds, toxic substances, and other material detrimental to plant growth. The composition of topsoil shall be in general accordance with ASTM D5268.

Amend topsoil pH range to obtain a pH of 5.5 to 7, tested in accordance with ASTM D4972. Topsoil shall have an organic matter content between 3 and 20 percent when tested by ASTM D2974. Topsoil shall have chemical attributes and nutrient content that is amenable to emergent vegetation and surface cover vegetation as specified. Topsoil shall have a maximum particle size of 1 inch in any dimension and shall have at least 15 percent but not more than 80 percent by weight passing the No 200 sieve when tested by ASTM D1140.

1.3.6 Hard/Unyielding Materials

Hard/Unyielding materials comprise weathered rock, dense consolidated deposits, or conglomerate materials with stones greater than 3 inches in any dimension or as defined by the pipe manufacturer, whichever is smaller. These materials usually require the use of heavy excavation equipment, ripper teeth, or jack hammers for removal.

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1.3.7 Unstable Material

Unstable materials are too wet to properly support the utility pipe, conduit, or appurtenant structure.

1.3.8 Expansive Soils

Expansive soils are defined as soils that have a plasticity index equal to or greater than 30 when tested in accordance with ASTM D4318.

1.4 SYSTEM DESCRIPTION

Boring logs provided in Section 00 31 32 GEOTECHNICAL DATA REPORT.

Variations may exist in the subsurface between boring locations.

1.4.1 Classification of Excavation

Finish the specified excavation on an unclassified basis.

1.4.2 Blasting

Blasting will not be permitted.

1.4.3 Water Control Plan

Submit procedures for accomplishing dewatering work and managing surface water. The water control plan shall be prepared by a professional engineer licensed in the Commonwealth of Puerto Rico.

1.5 SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government. Submit the following in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:

SD-01 Preconstruction Submittals

Shoring and Sheeting ; G, DO

Water Control Plan

Water control plan shall address dewatering and surface water management. Dewatering work plan shall include, but not be limited to: Identifying dewatering areas and dewatering activities, equipment list, narrative discussing means and methods for controlling surface and groundwater along with detailed calculations for anticipated water quantity and pump capacity, anticipated permits, measuring and monitoring plan for groundwater levels surrounding excavations, and anticipated treatment requirements. The plan should also provide calculations that demonstrate that the temporary excavation bottoms and sides are stable against groundwater pressures.

In-Channel Excavation Plan ; G, DO

Geotechnical Engineer Qualifications; G, DO

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Borrow Site ; G, DO

Disposal Site ; G, DO

SD-03 Product Data

Utilization of Excavated Materials ; G, DO Opening of any Excavation or Borrow Pit

SD-06 Test Reports

Testing

Borrow Site Testing

Within 24 hours of conclusion of physical tests, submit electronic copies of test results.

SD-07 Certificates

Testing

Laboratory Qualifications ; G, DO

1.6 IN-CHANNEL EXCAVATION RESTRICTIONS

1.6.1 Order of Work

Final depth excavation of the channel shall be completed from downstream to upstream (North to South) within the project limits, except for material removed for establishment of the required Bypass Channel as shown on the drawings. If necessary, for coordination purposes with other contracts or project schedule requirements, exceptions may be approved by the Contracting Officer.

1.6.2 Transportation of Material

Water and excavated material shall not be permitted to overflow or spill onto haul routes during transport to the disposal site. Contractor shall supply watertight hauling equipment and truck washdown racks at the project site. Cleanup of spilled material on the haul route shall be done by the Contractor at no cost to the Government. Any spills shall be promptly cleaned up and comply with all Federal, Commonwealth, and local environmental regulations.

1.7 APPROVED DISPOSAL SITE

The La Chuleta disposal site is approved for disposal of excavated soil material only and shall be managed by the Government. The Government may designate additional disposal sites within a 2 mile radius from the Rio Puerto Nuevo Contract 3 Project Site which shall be considered as Approved Disposal Sites. Construction waste, demolition debris, and clear and grubbing debris shall not be disposed of within La Chuleta. The Contractor is responsible for hauling operations including placing material in locations instructed by the Government. The Contractor is responsible to provide any necessary ramps, crawler, cranes or hoppers for barge tipping when offloading materials if delivered by barge to La Chuleta. The Government is responsible for, but not limited to, stormwater pollution prevention, containment, moisture control operations, dust control, and

SECTION 31 00 00 Page 9 grading. Contractor shall coordinate with Government to ensure efficient hauling operations.

The Contractor may utilize other disposal sites for excavated soil material and the Contractor shall be responsible for ensuring compliance with all Federal, Commonwealth, and local regulations. All operations including, but not limited to, hauling, placing, grading, moisture control, stormwater pollution prevention, containment, and dust control shall be the responsibility of the Contractor. Provide location, route, and provisions for meeting Federal, Commonwealth, and local regulations prior to the start of excavation operations.

PART 2 PRODUCTS

2.1 REQUIREMENTS FOR OFFSITE SOILS

Soil materials imported from offsite shall be free of environmental contaminants and must meet federal, state, and/or local environmental requirements for imported fill material. Tests shall be performed to document compliance with applicable environmental regulations before they are brought to the site.

At a minimum, offsite soils for use as fill shall be tested for Total Petroleum Hydrocarbons (TPH); Benzene, Toluene, Ethyl Benzene, and Xylene (BTEX). Fill shall contain a maximum of 100 parts per million (ppm) of total petroleum hydrocarbons (TPH) and a maximum of 10 ppm of the sum of Benzene, Toluene, Ethyl Benzene, and Xylene (BTEX), or shall meet applicable federal, state, and/or local requirements, whichever are more stringent. Determine TPH concentrations by using EPA 600/4-79/020 Method

418.1. Determine BTEX concentrations by using EPA SW-846.3-3 Method 5030/8020. Provide Borrow Site Testing for TPH and, BTEX from a composite sample of material from the borrow site, with at least one test from each borrow site . Do not bring material onsite until test results have been approved by the Contracting Officer.

Contractor shall provide documentation of physical properties of soils from the borrow source including ASTM D6913/D6913M and ASTM D1140 grain size, ASTM D4318 Atterberg limits, ASTM D2487 USCS classification, ASTM D2216 moisture content, ASTM D2974 organic content, and ASTM D1557 Proctor results.

Imported offsite soils shall meet the requirements in paragraph

SATISFACTORY MATERIALS.

2.2 GENERAL FILL MATERIAL

General Fill may be used as fill or backfill in areas to landscaped and shall not be used for structural backfill or support. General fill must be thoroughly mixed and free from debris, clods, seeds of nuisance or exotic species, or stones of a size larger than that specified in PARAGRAPH "Unsatisfactory Materials". In areas where general fill is placed at the ground surface where grass, sod, or landscaping material will be placed, general fill material shall not have stones larger than 1.5 inches in any dimension within the upper 1 foot of the general fill. General fill shall have an organic content of less than 5% by weight.

SECTION 31 00 00 Page 10

2.3 GRANULAR FILL MATERIALS

2.3.1 Select Fill Material

Select granular material consists of materials classified as GW, GP, SW, SP, SP-SM, and SP-SC by ASTM D2487 where indicated. The organic content shall be 2 percent or less when tested in accordance with ASTM D2974. Not more than 10 percent by weight may be finer than No. 200 sieve when tested in accordance with ASTM D1140. Provide a minimum coefficient of permeability of 0.002 feet per minute when tested in accordance with

ASTM D2434.

2.3.2 Structural Fill Material

ASTM D2487, classification GW, GP, GM, GC, GP-GM, GP-GC, SW, SP, SM, SC, SW-SM, SW-SC, or SP-SC with a maximum ASTM D4318 liquid limit of 35, a maximum ASTM D4318 plasticity index of 10, a maximum of 10 percent by weight passing ASTM D1140 No. 200 sieve, and a maximum of 2 percent when tested in accordance with ASTM D2974 organic content.

2.4 UNDERWATER PLACEMENT GRANULAR MATERIAL

Underwater placement granular material consists of materials classified as GW, GP, SW, and SP by ASTM D2487 where indicated. Material shall have a maximum particle size of 3 inches and consist of clean granular material that is free of debris and other deleterious material. Material shall have a maximum organic content of 2 percent when tested in accordance with ASTM D2974. Not more than 5 percent by weight may be finer than No. 200 sieve when tested in accordance with ASTM D1140.

2.5 WALL DRAINAGE MATERIAL

Wall drainage material consists of granular material meeting the requirements of PRHTA Specifications Section 209 - Sheathing, Part 209-2.01(a).

2.6 BEDDING MATERIAL

Bedding material for applications other than utility bedding shall consist of a granular mixture of well-graded sand and crushed gravel or aggregate, whose average size shall not exceed 0.5 inches and its gradation spans from 0.75 inches to Sieve No. 4. Compose material of tough, durable particles. Not more than 10 percent by weight may be finer than No. 200 sieve when tested in accordance with ASTM D1140. Fines passing the No.

200 standard sieve shall have a plasticity index less than six. (AASHTO A-1-a based on AASHTO M 145)

2.7 UTILITY BEDDING AND BACKFILL

Provide bedding for buried piping in accordance with AWWA C600, Type 4, except as specified herein or as indicated on the drawings. Utility bedding shall consiste of crushed stone material in accordance with ASTM C33/C33M Gradation No. 67. Provide materials as follows:

a. Bedding and Haunching: Bedding and haunching shall meet material requirements for bedding material.

b. Initial Backfill: Initial backfill shall meet material requirements for bedding material.

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c. Final Backfill: Final backfill shall meet material requirements for structural fill.

2.8 BURIED WARNING AND IDENTIFICATION TAPE

Buried warning and identification tape requirements are provided in Section 33 11 00 WATER UTILITY DISTRIBUTION PIPING.

2.9 DETECTION WIRE FOR NON-METALLIC PIPING

Insulate a single strand, solid copper detection wire with a minimum of 12

AWG.

2.10 MATERIAL FOR RIP-RAP

Rip-rap requirements are provided in Section 35 31 19 STONE, CHANNEL, SHORELINE/COASTAL PROTECTION FOR STRUCTURES.

2.11 PIPE CASING

2.11.1 Utility Casing Pipe

ASTM A139/A139M , Grade B, or ASTM A252, Grade 2, smooth wall pipe. Match casing size to the outside diameter and wall thickness as indicated on the drawings. Protective coating is not required on casing pipe.

2.11.2 Wood Supports

Locally available, rough, structural grade. Provide wood with nonleaching water-borne pressure preservative (ACA or CCA) and treatment conforming to AWPA P5. Secure wood supports to carrier pipe with stainless steel or zinc-coated steel bands.

2.12 GEOTEXTILES

Geotextile requirements are provided in Section 31 05 19 GEOTEXTILES.

PART 3 EXECUTION

3.1 STRIPPING OF TOPSOIL

Where indicated or directed, strip topsoil to a depth of the root zone or 4 inches , whichever is greater. Spread topsoil on areas already graded and prepared for topsoil, or transport and deposit in stockpiles convenient to areas that are to receive application of the topsoil later, or at locations indicated or specified. Keep topsoil separate from other excavated materials, brush, litter, objectionable weeds, roots, stones larger than 2 inches in diameter, and other materials that would interfere with planting and maintenance operations. Remove from the site any surplus of topsoil from excavations and gradings.

3.2 GENERAL EXCAVATION

Perform excavation of every type of material encountered within the limits of the project to the lines, grades, and elevations indicated and as specified. Perform the grading in accordance with the typical sections shown and the tolerances specified in paragraph FINISHING. Transport

SECTION 31 00 00 Page 12 satisfactory excavated materials that meet requirements for structural fill and place in fill or embankment within the limits of the work.

Excavate unsatisfactory materials encountered within the limits of the work below grade and replace with structural fill. Include such excavated material and the structural fill ordered as replacement in excavation.

Dispose surplus and unsatisfactory excavated material in accordance with paragraph UTILIZATION OF EXCAVATED MATERIALS and local and Commonwealth regulations. During construction, perform EARTHWORK in a manner and sequence that will provide proper drainage at all times. Excavate material required for fill or embankment in excess of that produced by excavation within the grading limits from the borrow areas indicated or from other approved areas selected by the Contractor as specified.

All excavations shall comply with Occupational Safety and Health Administration excavation, slopes and benching, and trenching and shoring regulations.

3.2.1 Ditches, Gutters, and Channel Changes

Finish excavation of ditches, gutters, and channel changes by cutting accurately to the cross sections, grades, and elevations shown on the drawings. Do not excavate ditches and gutters below grades shown.

Backfill the excessive open ditch or gutter excavation with satisfactory, thoroughly compacted, material or with suitable stone or cobble to grades shown at the Contractor's expense. Dispose excavated material as shown or as approved, except in no case allow material to be deposited within 4 feet from edge of a ditch. Maintain excavations free from detrimental quantities of leaves, brush, sticks, trash, and other debris until final acceptance of the work.

3.2.2 Drainage Structures

Make excavations to the lines, grades, and elevations shown. Provide trenches and foundation pits of sufficient size to permit the placement and removal of forms for the full length and width of structure footings and foundations as shown. Clean rock or other hard foundation material of loose debris and cut to a firm, level, stepped, or serrated surface.

Remove loose disintegrated rock and thin strata. Do not disturb the bottom of the excavation when concrete or masonry is to be placed in an excavated area. Any disturbed areas shall be repaired with bedding material compacted to a minimum 95 percent density as determined by AASHTO T 180 or ASTM D1557 as indicated in Section 1.2.4 of this specification at a moisture content within the range of -3 to +3 percent of optimum moisture content. Do not excavate to the final grade level until just before the concrete or masonry is to be placed. Repair of disturbed areas is incidental to installation of drainage structures and shall be performed by the Contractor at the Contractor's expense.

3.2.3 Drainage

Provide for the collection and disposal of surface and subsurface water encountered during construction. Completely drain construction site during periods of construction to keep soil materials sufficiently dry.

Construct storm drainage features at the earliest stages of site development, and throughout construction grade the construction area to provide positive surface water runoff away from the construction activity, or provide temporary ditches, swales, and other drainage features and equipment as required to maintain dry soils. When unsuitable working platforms for equipment operation and unsuitable soil support for

SECTION 31 00 00 Page 13 subsequent construction features develop, remove unsuitable material and replace with compacted structural fill material. It is the responsibility of the Contractor to assess the soil and groundwater conditions presented by the plans and specifications and to employ necessary measures to permit construction to proceed.

3.2.4 Dewatering

Dewatering for dry excavation is prohibited within the channel banks. The language herein applies to structural excavations and utility trenches outside of the channel limits.

Control groundwater flowing toward or into excavations to prevent caving of excavation slopes and walls, boils, uplift and heave in the excavation and to eliminate interference with orderly progress of construction. Do not permit French drains, sumps, ditches, or trenches within 3 feet of the foundation of any structure, except with specific written approval, and after specific contractual provisions for restoration of the foundation area have been made. Take control measures by the time the excavation reaches the water level in order to maintain the integrity of the in-situ material. While the excavation is open, maintain the water level continuously, at least 2 feet below the working level. Operate dewatering system continuously until construction work below existing water levels is complete. Submit performance records weekly. Measure and record performance of dewatering system at same time each day by use of observation wells or piezometers installed in conjunction with the dewatering system. Relieve hydrostatic head in pervious zones below subgrade elevation in layered soils to prevent uplift.

Dewatering systems shall be designed by a registered Geotechnical Engineer in the Commonwealth of Puerto Rico with at least 10 years of experience related to dewatering systems. The dewatering system may include sumps, pumps, or well points capable of meeting the project dewatering requirements.

3.2.5 Trench Excavation Requirements

Excavate the trench as recommended by the manufacturer of the pipe to be installed. Slope trench walls below the top of the pipe, or make vertical, and of such width as recommended in the manufacturer's printed installation manual. Provide vertical trench walls in the pipe zone where no manufacturer's printed installation manual is available. Shore trench walls more than 4 feet high, cut back to a stable slope, or provide with equivalent means of protection for employees who may be exposed to moving ground or cave in. Shore vertical trench walls more than 4 feet high, or excavate trench walls to the slopes as recommended by OHSA or the angle of repose, whichever results in a flatter slope. Give special attention to slopes which may be adversely affected by weather or moisture content. For pipes with outside diameter (O.D.) of 15 inches or smaller, the trench width shall be 24 inches greater than the pipe O.D. For pipes with outside diameter (O.D.) of 16 inches or larger, the trench width shall be 36 inches greater than the pipe O.D. Where recommended trench widths are exceeded, Contractor shall provide a redesign of the pipe segment that is certified by an engineer licensed in Puerto Rico that includes stronger pipe or special installation procedures to achieve the design ground surface loading with the same safety factor as the original design. The Contractor is responsible for the cost of redesign, stronger pipe, or special installation procedures without any additional cost to the Government.

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3.2.5.1 Bottom Preparation

Grade the bottoms of trenches accurately to provide uniform bearing and support for the bottom quadrant of each section of the pipe. Excavate bell holes to the necessary size at each joint or coupling to eliminate point bearing. Remove stones of 3 inch or greater in any dimension, or as recommended by the pipe manufacturer, whichever is smaller, to avoid point bearing.

3.2.5.2 Removal of Unyielding Material

Where unyielding material is encountered in the bottom of the trench, remove such material 6 inches below the required grade and replace with select granular material as provided in paragraph BACKFILLING AND

COMPACTION

3.2.5.3 Removal of Unstable Material

Where unstable material is encountered in the bottom of the trench, remove such material to the depth directed and replace it to the proper grade with select granular material as provided in paragraph BACKFILLING AND

COMPACTION.

3.2.5.4 Excavation for Appurtenances

Provide excavation for manholes, catch-basins, inlets, or similar structures sufficient to leave at least 12 inches clear or adequate space to allow for compaction equipment and testing between the outer structure surfaces and the face of the excavation or support members. Clean loose debris and cut to a firm surface either level, stepped, or serrated, as shown. Remove loose disintegrated rock and thin strata. Remove and replace unstable material as required to comply with contract requirements. When concrete or masonry is to be placed in an excavated area, take special care not to disturb the bottom of the excavation. Do not excavate to the final grade level until just before the concrete or masonry is to be placed.

3.2.5.5 Jacking, Boring, and Tunneling

Unless otherwise indicated, provide excavation by open cut. Contractor may propose installing pipes by jacking, boring, or tunneling if work can be conducted safely and pipe and backfill can be properly installed and compacted, subject to the approval of the Contracting Officer.

3.2.6 Underground Utilities

The Contractor is responsible for movement of construction machinery and equipment over pipes and utilities during construction. Perform work adjacent to non-Government utilities as indicated in accordance with procedures outlined by utility company. Excavation made with power-driven equipment is not permitted within 2 feet of known utility or subsurface construction. For work immediately adjacent to or for excavations exposing a utility or other buried obstruction, excavate by hand. Start hand excavation on each side of the indicated obstruction and continue until the obstruction is uncovered or until clearance for the new grade is assured. Support uncovered lines or other existing work affected by the contract excavation until approval for backfill is granted by the Contracting Officer. Report damage to utility lines or subsurface

SECTION 31 00 00 Page 15 construction immediately to the Contracting Officer.

3.2.7 Structural Excavation

Ensure that foundation subgrades have been inspected and approved by the Contracting Officer prior to concrete placement.

3.2.8 Drilled Shaft Wall Monitoring

Excavation and material compaction shall be performed in a manner to avoid damage to the drilled shafts walls. Drilled shafts walls shall be monitored in accordance with Section 31 63 29 DRILLED CONCRETE PIERS AND SHAFTS. Prevent damage to drilled shafts caused by any excavation and backfill near drilled shaft walls. Repair any damage to drilled shafts at the Contractor's expense as specified in Section 31 63 29 DRILLED CONCRETE

PIERS AND SHAFTS.

3.3 IN-CHANNEL EXCAVATION PLAN

Provide a description of equipment and methods utilized in the removal of the material within the channel banks. The plan shall include provisions for maintaining stable slopes, grade control methods, hauling equipment, method for transporting wet materials, truck washing, and methods for excavating near structures as describe in the paragraph STRUCTURAL OFFSETS below. Refer to specification section 35 20 23 DREDGING for requirements of hydraulic or barge-based mechanical dredging if method is elected for use by the Contractor.

3.3.1 Required Depth

The designated areas to be excavated, to final channel invert as shown on the Contract Drawings, will be estimated and paid for in accordance with the provisions contained in the subparagraphs "Measurement" and "Payment" of Section 01 22 00 MEASUREMENT AND PAYMENT.

3.3.2 Structural Offsets

Structural elements shall be protected from damage during adjacent material removal. Damage to structural elements during material removal shall be repaired or replaced at the discretion of the Contracting Officer at no additional cost to the Government. Provide within the in-channel excavation plan provisions to excavate within 5 feet of structural elements that includes a description of equipment and methods to be used.

Use equipment and methods for excavation and removal of material will minimize the potential for damage to structures. Damaged caused to existing structures and drilled shaft concrete shall be repaired at no expense to the Government. Turbidity and monitoring in Section 01 57 25 TURBIDITY AND DISPOSAL MONITORING requirements shall be met regardless of method utilized.

3.4 SELECTION OF BORROW MATERIAL

Select borrow material to meet the requirements and conditions of the particular fill or embankment for which it is to be used. Obtain borrow material from the required excavation areas within the limits of the project site, selected by the Contractor, or from approved off-site sources identified by the Contractor. Unless otherwise provided in the contract, the Contractor is responsible for obtaining the right to procure material, pay royalties and other charges involved, and bear the expense

SECTION 31 00 00 Page 16 of developing the sources, including rights-of-way for hauling from the owners. Borrow material from approved sources on Government-controlled land may be obtained without payment of royalties. Unless specifically provided, do not obtain borrow within the limits of the project site without prior written approval. Contractor shall be responsible for necessary clearing, grubbing, and satisfactory drainage of borrow pits and the disposal of debris related to the borrow excavation operations.

3.5 OPENING AND DRAINAGE OF EXCAVATION AND BORROW PITS

Notify the Contracting Officer 7 days in advance of the opening of any excavation or borrow pit or borrow areas to permit elevations and measurements of the undisturbed ground surface to be taken. Provide documentation of material types and physical properties within the source, including grain size by ASTM D6913/D6913M , Atterberg limits by ASTM D4318, USCS classification by ASTM D2487, moisture content by ASTM D2216, organic content by ASTM D2974, and Proctor results by ASTM D1557. Provide documentation that material is free from contaminants and other deleterious matter. Except as otherwise permitted, excavate borrow pits and other excavation areas by providing adequate drainage at all times.

Transport overburden and other spoil material to designated spoil areas or otherwise dispose of as approved. Provide neatly trimmed and drained borrow pits after the excavation is completed. Ensure that excavation of any area, operation of borrow pits, or dumping of spoil material results in minimum detrimental effects on natural environmental conditions.

3.6 SHORING AND SHEETING

3.6.1 General Requirements

Submit a Shoring and Sheeting plan for approval prior to starting work in accordance with PARAGRAPH 1.4 of this specification. Submit drawings and calculations, certified by an experienced professional engineer licensed in Puerto Rico, describing the methods for shoring and sheeting of excavations.

a. Prevent undermining of pavements, foundations and slabs.

b. Prevent slippage or movement in banks or slopes adjacent to the excavation.

c. Allow for the abandonment of shoring and sheeting materials in place in critical areas as the work is completed. In these areas, backfill the excavation to within 3 feet of the finished grade and remove the remaining exposed portion of the shoring before completing the backfill.

Finish shoring, including sheet piling, and install as necessary to protect workmen, banks, adjacent paving, structures, and utilities.

Remove shoring, bracing, and sheeting as excavations are backfilled in a manner to prevent deformation or caving.

3.6.2 Contractor's Geotechnical Engineer

Hire a Professional Geotechnical Engineer licensed in the Commonwealth of Puerto Rico to provide inspection of excavations and soil/groundwater conditions throughout construction. The Geotechnical Engineer shall have at least 10 years of professional experience performing similar work and is responsible for performing pre-construction and periodic site visits throughout construction to assess site conditions. The Geotechnical Engineer is responsible for updating the excavation, sheeting, and

SECTION 31 00 00 Page 17 dewatering plans as construction progresses to reflect changing conditions and submit an updated plan if necessary. Submit a monthly written report, informing the Contractor and Contracting Officer of the status of the plan and an accounting of the Contractor's adherence to the plan addressing any present or potential problems. The Contractor shall make the Geotechnical Engineer available to meet with the Contracting Officer upon the Contracting Officer's request throughout the contract duration.

3.7 GRADING AREAS

Where indicated, divide work into grading areas within which satisfactory excavated material will be placed in embankments, fills, and required backfills. Do not haul satisfactory material excavated in one grading area to another grading area except when so directed in writing. Place and grade stockpiles of satisfactory materials as specified. Keep stockpiles in a neat and well drained condition giving due consideration to drainage at all times. Clear, grub, and seal by rubber-tired equipment, the ground surface at stockpile locations. Protect stockpiles of satisfactory materials from contamination which may destroy the quality and fitness of the stockpiled material. If the Contractor fails to protect the stockpiles, and any material becomes unsatisfactory, remove and replace such material with satisfactory material from approved sources at no additional cost to the Government.

3.8 GROUND SURFACE PREPARATION

The ground surface shall be prepared in accordance with the subgrade preparation requirements in paragraph SUBGRADE PREPARATION.

3.9 UTILIZATION OF EXCAVATED MATERIALS

Dispose surplus and unsatisfactory excavated material offsite in accordance with all local and Commonwealth regulations. Dispose debris removed from areas to be dredged or excavated off-site at an approved landfill. Dry material obtained above the mean higher high water mark (approximately El. +1.0) shall be designated for disposal at the La Chuleta site or an approved disposal site. Excavated material obtained below the mean higher high water mark will have high water content and shall be disposed at the designated Ocean Dredged Material Disposal Site (ODMDS). See specification section 35 20 23 DREDGING for additional requirements related to disposal at the ODMDS.

Use satisfactory material removed from excavations that meets material specifications in the construction of fills, embankments, subgrades, bedding, backfill, and for similar purposes. Submit procedure for disposal of unused satisfactory material. Do not waste any satisfactory excavated material without specific written authorization. Do not dispose excavated material to obstruct the flow of any stream, endanger a partly finished structure, impair the efficiency or appearance of any structure, or be detrimental to the completed work in any way.

3.10 BURIED DETECTION WIRE

3.10.1 Buried Detection Wire

Bury detection wire directly above non-metallic piping at a distance not to exceed 12 inches above the top of pipe. Extend the wire continuously and unbroken, from manhole to manhole. Terminate the ends of the wire inside the manholes at each end of the pipe, with a minimum of 3 feet of

SECTION 31 00 00 Page 18 wire, coiled, remaining accessible in each manhole. Furnish insulated wire over its entire length. Install wires at manholes between the top of the corbel and the frame and extend up through the chimney seal between the frame and the chimney seal. For force mains, terminate the wire in the valve pit at the pump station end of the pipe.

3.11 BACKFILLING AND COMPACTION

Except where otherwise directed in this Section, place backfill adjacent to any and all types of structures in successive horizontal layers of loose material not more than 8 inches in depth. Restrict maximum lift thickness to 6 inches in narrow placement areas or adjacent to structures where manually operated compaction equipment is used such as tamper, jumping jacks, walk-behind rollers, and other similar equipment. Compact to at least 95 percent laboratory maximum density per AASHTO T 180 or ASTM D1557 as indicated in paragraph DEGREE OF COMPACTION of this specification. Prevent wedging action or eccentric loading upon or against the structure. Backfill material must be within the range of -3 to +3 percent of optimum moisture content at the time of compaction.

Heavy equipment for spreading and compacting fill material shall not be operated closer than 5 feet from drilled shaft walls, 15 feet from sheet pile walls, or a distance equal to the retained soil height for other features. Compaction close to these structures shall be performed using manually-operated small compaction equipment such as tampers, jumping jacks, or walk-behind rollers, or similar equipment.

No embankment backfill will be allowed above jet grouted locations until after 28 days of curing time or test results indicate the jet grout has achieved a compressive strength of 100 psi at 28 days.

Prepare ground surface on which backfill is to be placed and compact backfill materials in conformance with the applicable portions of paragraphs GROUND SURFACE PREPARATION. Finish compaction by sheepsfoot rollers, pneumatic-tired rollers, steel-wheeled rollers, vibratory compactors, or other approved equipment as required to achieve the specified compaction.

In areas that require fill below the water level within adjacent channels, underwater placement granular material shall be placed in 18-inch thick lifts and spread and compacted using the equipment placing the fill such as the arm of a backhoe. Underwater fill shall continue until reaching 2 feet above the water level to obtain a bridge lift. Any additional fill to be placed above the bridge lift will be placed and compacted to at least 95 percent laboratory maximum density per AASHTO T 180 or ASTM D1557 as indicated in Section 1.2.4 of this specification at a moisture content within the range of -3 to +3 percent of optimum moisture content..

3.11.1 Trench Backfill

Backfill trenches to the grades provided in specification and on drawings. Backfill the trench to 2 feet above the top of pipe prior to performing the required pressure tests. Leave the joints and couplings uncovered during the pressure test. Do not backfill the trench until all specified tests are performed.

3.11.1.1 Replacement of Unyielding Material

Replace unyielding material removed from the bottom of the trench with

SECTION 31 00 00 Page 19 select granular material or initial backfill material.

3.11.1.2 Replacement of Unstable Material

Replace unstable material removed from the bottom of the trench or excavation with select granular material placed in layers not exceeding 8 inches loose thickness and compacted to 95 percent of AASHTO T 180 or ASTM D1557 maximum density as indicated in Section 1.2.4 of this specification at a moisture content within the range of -3 to +3 percent of optimum moisture content.

3.11.1.3 Utility Bedding and Initial Backfill

Provide bedding of the type and thickness shown. Place initial backfill material in maximum 6-inch loose lifts and compact lifts with approved light-weight manually operated compaction equipment, such as tampers and jumping jacks to a height of at least one foot above the utility pipe or conduit. Bring up the backfill evenly on both sides of the pipe for the full length of the pipe. Take care to ensure thorough compaction of the fill under the haunches of the pipe. Compact utility bedding and initial backfill to 90 percent of ASTM D4253 maximum density as indicated in paragraph DEGREE OF COMPACTION of this specification.

3.11.1.4 Final Backfill

Fill the remainder of the trench, except for special materials for roadways with final backfill material. Place final backfill material in maximum 8 inch loose lifts and compact. Compact to at least 95 percent laboratory maximum density AASHTO T 180 or ASTM D1557 as indicated in paragraph DEGREE OF COMPACTION of this specification. Prevent wedging action or eccentric loading upon or against structures. Backfill material must be within the range of -3 to +3 percent of optimum moisture content at the time of compaction.

3.11.1.4.1 Roadways

Place final backfill up to the required elevation as specified. Do not permit water flooding or jetting methods of compaction.

3.11.2 Backfill for Appurtenances

After the manhole, catch basin, inlet, or similar structure has been constructed and the concrete has been allowed to cure for 14 days, place backfill in such a manner that the structure is not be damaged by falling earth. Deposit the backfill material, compact it as specified for final backfill, and bring up the backfill evenly on all sides of the structure to prevent eccentric loading and excessive stress.

3.12 SPECIAL REQUIREMENTS

Special requirements for both excavation and backfill relating to the specific utilities are as follows:

3.12.1 Gas Distribution

Excavate trenches to a depth that will provide a minimum 18 inches of cover in rock excavation and a minimum 24 inch of cover in other excavation.

SECTION 31 00 00 Page 20

3.12.2 Water Lines

Excavate trenches to a depth that provides a minimum cover of 2 feet from the existing ground surface, or from the indicated finished grade, whichever is lower, to the top of the pipe.

3.12.3 Electrical Distribution System

Provide a minimum cover of 24 inches from the finished grade to direct burial cable and conduit or duct line, unless otherwise indicated.

3.13 ROADWAY EMBANKMENTS

3.13.1 Roadway Earth Embankments

Construct roadway earth embankments from structural fill material free of organic material and rocks with any dimension greater than 3 inches .

Place the material in successive horizontal layers of loose material not more than 8 inches in depth. Spread each layer uniformly on a soil surface that has been moistened or aerated as necessary, and scarified to a depth of not less than 2 inches or otherwise broken up so that the fill will bond with the surface on which it is placed. After spreading, plow, disk, or otherwise break up each layer; moisten or aerate as necessary;

thoroughly mix; and compact to at least 95 percent laboratory maximum density from AASHTO T 180 or ASTM D1557 as indicated in Section 1.2.4 of this specification.