W91238-18-R-0068_SPEC_2142_AM03_20180814.pdf

SOLICIATION NO. W91238-18-R-0068

1 of 1 AM0003

YUBA RIVER BASIN, CALIFORNIA

MARYSVILLE RING LEVEE PHASE 2A SOUTH

YUBA COUNTY, CALIFORNIA

AMENDMENT 0003 - SUMMARY:

A) SPECIFICATION 2142

1) Replaced entire Submittal Register

2) Replaced entire Section 31 38 13.

SUBMITTAL FORM,Jan 96 PREVIOUS EDITION IS OBSOLETE PAGE 1 OF 2 PAGES

Marysville Ring Levee Phase 2A South

31 83 13 SD-01 Preconstruction Submittals

3.2.1 G DOProduction Plan

3.2.1.1 G DOOperation Plan

3.2.1.4 G DOQualification Submittal

3.2.1.5 GSample Quality Control Records

3.2.1.6 G DOSchedule and Sequence of

Operations

3.2.1.7 GSequence of Operations At Utility

Line Crossings

3.2.1.8 G DOSampling Plan

3.2.4 G DOCutoff Wall Production Plan

3.2.1.9 G DOCutoff Wall Surcharge Loading

Plan

3.5.1.3 G DOSoil Mixing Operation Plan

3.2.1.2Description Of The Equipment

And Procedures

3.2.1.1 G DOLayout Of Operations

SD-03 Product Data

2.1.4 G DOAdmixtures

SD-04 Samples 3.7.1.3Wet Bulk Samples 3.7.1.3Chain of Custody Form for

Quality Assurance Samples

3.5.1.2 G DOTrial Mix Designs

SD-05 Design Data

SUBMITTAL REGISTER

CONTRACT NO.

TITLE AND LOCATION CONTRACTOR

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SUBMITTAL FORM,Jan 96 PREVIOUS EDITION IS OBSOLETE PAGE 2 OF 2 PAGES

Marysville Ring Levee Phase 2A South

31 83 13 3.5.1.2 G DOCutoff Wall SCB Material Mix Design

3.2.1.2 GProposed Mix Design And

Construction Methods

SD-06 Test Reports 3.7.3.2Calibration Results 2.2.2Water Quality Test Report

3.7.3.2 GAs-Built Profile of Cutoff Wall and

End of Construction Summary Report

1.2.2 G DOConstruction Quality Control Test

Results

1.2.2 G DOConstruction Quality Control Test

Results

3.7.3.2Daily Field Quality Control Reports

3.5.1.2 GSCB Mix Design Test Report

3.5.1.2 G DODemonstration Section Test

Report SD-07 Certificates

2.1.2Cement Certification 2.1.3Bentonite Certification 2.1.4Admixture Certification

SUBMITTAL REGISTER

CONTRACT NO.

TITLE AND LOCATION CONTRACTOR

CONTRACTOR:

SCHEDULE DATES

CONTRACTOR

ACTION

APPROVING AUTHORITY

A C T I V I T Y

N O

T R A N S M I T T A L

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(a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) (l) (m) (n) (o) (p) (q) (r)

Marysville Ring Levee Phase 2A South 2142

SECTION TABLE OF CONTENTS

DIVISION 31 - EARTHWORK

SECTION 31 83 13

CUTOFF WALL DEEP MIXING METHOD

PART 1 GENERAL

1.1 REFERENCES

1.2 SYSTEM DESCRIPTION

1.2.1 Design Requirements

1.2.2 Acceptance Requirements

1.2.2.1 Demonstration Section Only

1.3 SUBMITTALS

1.4 QUALITY CONTROL

1.4.1 Coordination of Laboratories

1.4.2 Rejected Work

1.5 QUALIFICATIONS

1.5.1 Soil Mixing Equipment Operator

1.5.2 Soil Mixed Grout Plant Operator

1.5.3 Soil-Mixed Cutoff Wall Specialist

1.6 GENERAL CONDITIONS

1.6.1 Access and Ramps

1.6.2 Protection of Existing Facilities

1.6.3 Construction Methods

1.6.4 Sequencing of Work

1.6.5 Water for Construction

1.6.6 Obstructions

1.6.7 Demonstration Section

1.7 SITE CONDITIONS

1.8 MAINTENANCE

1.8.1 Extra Materials

PART 2 PRODUCTS

2.1 MATERIALS

2.1.1 Material Storage Facility

2.1.2 Cement

2.1.3 Bentonite

2.1.4 Admixtures

2.2 WATER

2.2.1 Supply

2.2.2 Quality

PART 3 EXECUTION

3.1 MOBILIZATION

3.2 PREPARATION

3.2.1 Preconstruction Submittals

3.2.1.1 Operation Plan

3.2.1.2 Soil Mixing Equipment

3.2.1.3 Binder Delivery Methods and Equipment

3.2.1.4 Qualification Submittal

3.2.1.5 Sample Quality Control Records

31 83 13 - 1

IIAM0003

3.2.1.6 Schedule and Sequence of Operations

3.2.1.7 Sequence Of Operations At Utility Line Crossings

3.2.1.8 Sampling Plan

3.2.1.9 Cutoff Wall Surcharge Loading Plan

3.2.2 Working Platform

3.2.3 Determination of Impermeable Layer Depth

3.2.4 Rig Assembly

3.2.5 Grout Plant Assembly

3.2.6 Rig Movement to Work Area

3.3 MATERIAL DELIVERY AND INJECTION

3.3.1 Deliveries

3.3.2 Silo Loading

3.3.3 Batching, Mixing and Agitation

3.3.4 Pumping

3.3.5 Air Injection

3.3.6 Injection

3.3.6.1 Leads

3.3.6.2 Ports

3.4 EQUIPMENT

3.4.1 Soil Mixing Apparatus

3.4.2 Electronic Sensors

3.4.3 Penetration Depth Marking

3.4.4 Cement/Bentonite Slurry Plant

3.4.5 Replacement Parts

3.5 INSTALLATION

3.5.1 Demonstration Section

3.5.1.1 Location

3.5.1.2 Mix Design Development

3.5.1.3 Establishment of Mixing Index

3.5.1.4 Core Drilling and Virtual Cores

3.5.1.5 Special Quality Control Testing

3.5.2 Heading Construction

3.5.2.1 Element Sequencing

3.5.2.2 Element to Element Connections

3.5.2.3 Production Breaks

3.5.2.4 Heading Connections

3.5.3 Element Construction

3.5.3.1 Construction Staking

3.5.3.2 Rig Positioning

3.5.3.3 Predrilling

3.5.3.4 Material Mixing

3.5.3.5 Mixing Technique

3.5.3.6 Construction Progress

3.5.3.7 Grout Injection Rate

3.5.3.8 Bentonite/Cement Slurry Injection Rate Modification

3.5.3.9 Mixing Index Modifications

3.5.4 Depth Modifications

3.6 DEMOBILIZATION

3.6.1 Cleanup

3.6.2 Disposal or Waste Materials

3.6.3 Survey Monuments

3.7 FIELD QUALITY CONTROL

3.7.1 Materials Testing

3.7.1.1 Sample Collection and Testing

3.7.1.2 Grout Testing

3.7.1.3 Wet Bulk Sampling

3.7.1.4 Permeability Testing

3.7.1.5 Strength Testing

3.7.2 Rig Instrumentation and Telemetry

31 83 13 - 2

3.7.2.1 Installation Records

3.7.2.2 Mixing Technique

3.7.2.3 Wall Continuity

3.7.2.4 Soil Mixing Apparatus Rotation Speed and Penetration and

Withdrawal Rates

3.7.2.5 Bentonite/Cement Slurry Injection Rate

3.7.2.6 Modifications to Injection Rate

3.7.2.7 Continuous real time monitoring and recording of the

following soil mixing parameters.

3.7.3 Reporting

3.7.3.1 Materials Testing

3.7.3.2 Daily Reports

3.8 PROTECTION OF CUTOFF WALL

-- End of Section Table of Contents --

31 83 13 - 3

SECTION 31 83 13

CUTOFF WALL DEEP MIXING METHOD

PART 1 GENERAL

1.1 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 PETROLEUM INSTITUTE (API)

API RP 13B-1 (2009; Errata 2014) Recommended Practice for Field Testing Water-Based Drilling Fluids(2009; R 2016) Recommended Practice for Field Testing Water-Based Drilling Fluids

API Spec 13A (2010; Errata 1 2014; Errata 2-3 2015) Specification for Drilling-Fluid Materials

ASTM INTERNATIONAL (ASTM)

ASTM C150/C150M (2015) Standard Specification for Portland Cement(2017) Standard Specification for Portland Cement

ASTM D2488 (2009a) Description and Identification of Soils (Visual-Manual Procedure)

ASTM D422 (1963; R 2007; E 2014; E 2014)

Particle-Size Analysis of Soils

ASTM D4318 (2010; E 2014) Liquid Limit, Plastic Limit, and Plasticity Index of Soils

ASTM D4380 (2012) Standard Test Method for Density of Bentonitic Slurries

ASTM D4832 (2010) Preparation and Testing of Controlled Low Strength Material (CLSM) Test Cylinders

ASTM D 6914 Standard Practice for Sonic Drilling for Site Characterization and the Installation of Subsurface Monitoring Devices

U.S. ENVIRONMENTAL PROTECTION AGENCY (EPA)

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

EPA 3005A (1990) Acid Digestion of Aqueous Samples

31 83 13 - 4 and Extracts for Total Metals for Analysis by FLAA or ICP Spectroscopy

EPA 3510C (1990) Separatory Funnel Liquid-Liquid Extraction

EPA 5030B (1990) Purge and Trap for Aqueous Samples

EPA 6010C (1990) Inductively Coupled Plasma-Atomic Emission Spectrometry

EPA Modified 8015 (1990) Nonhalogenated Organics Using Purge and Trap (GC/FID)

EPA 8041A (1990) Organophosphorus Compounds by Gas Chromatography: Capillary Column Technique

EPA 8081A (1990) Organochlorine Pesticides by Gas Chromatography

EPA 8260B (1990) Volatile Organic Compounds by Gas Chromatography/Mass Spectrometry (GC/MS)

1.2 SYSTEM DESCRIPTION

The work covered by this section consists of furnishing all plant, labor, equipment and materials; performing all operations, including quality control and quality acceptance testing; and preparation of an end-of-construction summary report and as-built drawings in connection with the construction of a soil-cement-bentonite (SCB) cutoff wall. The cutoff wall methodology presented in this section may be used for construction of any cutoff wall features in this project, but is required to be the utilized method from STA 210+00 to 237+00. Any references within this section to "cutoff wall" or "seepage cutoff wall" refers to a cutoff wall constructed using the methodologies of this section unless otherwise specified.

1.2.1 Design Requirements

The cutoff wall must be constructed using in situ soil mixing methods capable of meeting the requirements of this section and classified as either: Wet Rotary Shaft (WRS), Wet Rotary End (WRE), Wet Rotary and Jet End (WJE) or Wet Vertical Panel (WVP), as described in the Federal Highway Administration manual Deep Mixing For Embankment and Foundation Support.

Methods that do not use mechanical soil cutting or mixing methods are not acceptable. The SCB cutoff wall must be constructed in accordance with these Sspecifications and as shown on the Drawings. The design intent is to produce an incompressible, relatively low-strength, low-permeability, continuous cutoff wall. The permeability shouldshall be less than 5 x 10^-7 centimeters per second. The target strength of the cutoff wall should be between 50 and 300 pounds per square inch (psi) with a maximum allowable range of 30 to 500 psi. The cutoff wall should be continuous between the starting and ending points for each alignment, with an appropriate overlap between elements and headings to ensure continuity to full depth. The cutoff wall must consist of either a series of overlapping SCB elements, formed underground through and beneath the levee, or by a full-depth horizontal advancement. Individual elements are joined utilizing overlaps, forming a continuous soil-mixed cutoff wall along the entire alignment.

The cutoff wall must extend a minimum of five (5) feet into the impervious

31 83 13 - 5 stratum.

1.2.2 Acceptance Requirements

Final acceptance of the cutoff wall will be based on the Quality Control (CQC) Records as identified in the Rig-Shift Reports, CQCConstruction Quality Control test results, and Government's Qquality Aassurance test results. Both Contractor and the Government testing must demonstrate that the cContract requirements are met prior to acceptance of the work. If during the course of construction the Contractor QC testing indicates noncompliance with these Sspecifications, immediately notify the Contracting Officer in writing. Notification must include the remedial action to be taken to bring the work/products back into compliance. The following is the acceptance criteria for the wall. Items a) through g) below refer to both the demonstration section and production work. In the event a dispute about the quality of the cutoff wall in the production work, the items in the Demonstration Section Only will be used to evaluate the quality in the disputed location. Refer to the entire Sspecification and Ddrawings for all the cContract requirements.

a). Wall bottom elevation: As shown on the drawings or as modified by the verification borings, or as directed by the Contracting Officer.

b). Width of wall: minimum 24 inch, average 27 inch as measured in the horizontal plane perpendicular to the wall alignment.

c). Wall continuity: All elements connected by an overlap meeting the requirements of the respective overlap type.

d). Unconfined compressive strength: 95 percent of results between 50 psi and 250300 psi at 28 days, and 100 percent of results between 2530 psi and 500 psi.

e). Wet bulk sample permeability: Maximum 5x10-7 cm/sec at 28 days.

f). Mixing index with allowed deviation established during demonstration section (Mixing Index is defined in Mixing Index Development).

g). Homogeneity which is defined as no unmixed soil inclusions greater than three inches. Defects are defined as incomplete soil-mixed zones greater than 3-inches maximum diameter, as indicated by the cutoff wall cores and the downhole probe sensors. These include voids, seams, cracks or other fissures that indicate the presence of unmixed zones.

Cracks that are caused by mechanical (i.e. from drill tooling) or hydraulic (i.e. hydro-fracturing) action during drilling of the borehole are not considered defects.

1.2.2.1 Demonstration Section Only

The following tests are used in the demonstration section only.

a). Falling and rising head tests: Under the Falling and Rising Head Tests homogeneity is considered passing if the bulk permeability calculated by the test is less than or equal to the permeability requirement for SCB matrix material from wet grab samples. The falling or rising head tests will be evaluated by use of the methods of Bouwer-Rice corrected for cutoff wall boundary conditions per Teeters

31 83 13 - 6 and Clemence to determine the bulk permeability of the cutoff wall. If either the rising head test or the falling head test exhibit a head change equivalent to or less than the permeability described above, the test location will be considered passing.

b). Verticality Test: The Verticality Test passes if the borehole is complete to depth (i.e. entirely within SCB material), and overlap at every depth is evident from core recovery and borehole probe data. The Verticality Test fails, for example, if the borehole drifts out of the SCB cutoff wall material and cannot be explained by the downhole probe spatial data at that depth. If conclusive evidence from the downhole probe indicates that the boring misalignment exceeds the cContractually allowable limits of cutoff wall verticality variance, the test is thrown out and no evaluation of pass or fail is made by the Government at that test location and the Contractor is to perform another test at different location at no additional cost to the Government.

1.3 RELATED SECTIONS

Section 01 33 00 SUBMITTAL PROCEDURES

Section 01 45 00 QUALITY CONTROL

Section 01 50 02 TEMPORARY CONSTRUCTION FACILITIES

Section 02 02 00 SUBSURFACE DATA

Section 31 00 00 EARTHWORK

1.3 SUBMITTALS

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

submittals not having a "G" designation are for information only or as otherwise designated. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government. The following must be submitted in accordance with Section

01 33 00 SUBMITTAL PROCEDURES:

SD-01 Preconstruction Submittals

Production Plan; G DO

Operation Plan; G DO

Qualification Submittal; G DO

Sample Quality Control Records; G DO

Schedule and Sequence of Operations; G DO

Sequence of Operations At Utility Line Crossings; G

Sampling Plan; G DO

Cutoff Wall Production Plan; G DO

Cutoff Wall Surcharge Loading Plan; G DO

31 83 13 - 7

Soil Mixing Operation Plan; G DO

Description Of The Equipment And Procedures

Layout Of Operations; G DO

SD-03 Product Data

Admixtures; G DO

SD-04 Samples

Wet Bulk Samples

Chain of Custody Form for Quality Assurance Samples

Trial Mix Designs; G DO

SD-05 Design Data

Cutoff Wall SCB Material Mix Design; G DO

Proposed Mix Design And Construction Methods; G

SD-06 Test Reports

Mix Design Report; G

Soil Mixing Plan; G

Demonstration Section Report; G

Calibration Results

Water Quality Test Report

As-Built Profile of Cutoff Wall and End of Construction Summary Report; G

Construction Quality Control Test Results

Daily Field Quality Control Reports

SCB Mix Design Test Report; G

Demonstration Section Test Report; G DO

Construction Quality Control Test Results; G DO

SD-07 Certificates

Cement Certification

Bentonite Certification

Admixture Certification

31 83 13 - 8

1.4 QUALITY CONTROL

1.4.1 Coordination of Laboratories

The CQC laboratory representative must meet weekly with the Government's Q uality Assurancequality assurance laboratory representative to coordinate all aspects of their work. Eliminate differences in sampling, handling, transporting, storing and testing methods. If discrepancies in the test results from the two labs are noted, the ChiefManager of the Quality Control Laboratory and the ChiefManager of the Qquality Aassurance Laboratory must visit and inspect each other's laboratory facilities for the purpose of eliminating the differences and discrepancies. The Chief Manager of the Quality Control Laboratory must report the findings to the Contracting Officer.

1.4.2 Rejected Work

Rejected work will be repaired by construction of a new heading between the last two locations of acceptable tests. The new heading will be constructed immediately adjacent to the existing cutoff wall on the waterside.

1.5 QUALIFICATIONS

1.5.1 Contractor

Qualifying experience in soil-mixed cutoff wall construction projects in within the last 10 years from this solicitation (year issued). Multiple headings on any one contract is considered as one construction project.

The project experience must have been performed by the entity that performs the work as defined below. An individual's experience from former companies does not qualify as soil-mixed cutoff wall construction project experience for the Contractor. An individual may be considered as a Soil-Mxed Cutoff Wall Specialist for this project. The qualifying experience in cutoff wall construction projects must consist of the following: Satisfactorily completed the construction of at least two soil-cement or soil-cement-bentonite (SCB) cutoff walls using the in place soil mixing method. The cutoff wall must have had a minimum depth of 70 feet and a minimum area of 100,000 square feet and a minimum width of 24 inches. The cutoff wall properties must include a maximum permeability of

1 x 10-6 cm/sec. The in situ soil mixing cutoff wall methods must be as classified as either: Wet Rotary Shaft (WRS), Wet Rotary End (WRE), Wet Rotary and Jet End (WJE) or Wet Vertical Panel (WVP), as described in the Federal Highway Administration manual Deep Mixing For Embankment and Foundation Support. Methods that do not use mechanical soil cutting or mixing methods are not acceptable.

1.5.1 Soil Mixing Equipment Operator

The Soil Mixing Equipment Operator(s) must have experience in using similar equipment to be used for this solicitation in a minimum of two successfully completed projects and a minimum of five years of experience similar to the projects described in paragraph Contractor above. The projects listed in the resume must be similar to this solicitation including, but not limited:

comparable scope, complexity and physical size completed.

1.5.2 Soil Mixed Grout Plant Operator

The Grout Plant Operator(s) must have experience in using similar grout

31 83 13 - 9 plant equipment to be used for this solicitation in a minimum of two successfully completed projects and a minimum of five years of experience similar to the projects described in paragraph Contractor above. The projects listed in the resume must be similar to this solicitation including, but not limited: comparable scope, complexity and physical size completed.

1.5.3 Soil-Mixed Cutoff Wall Specialist

The Soil-Mixed Cutoff Wall Specialist(s) must be experienced in providing supervision of mix design and field control composition and mixing of the soil-cement or soil-cement bentonite using in situ soil mixing equipment.

The projects listed in the resume must include a minimum of two successfully completed projects and a minimum of five years of experience on projects similar in scope, project type, physical size and complexity to this solicitation and meeting the project criteria in paragraph Contractor above. The experience must include but not limited to: (1) controlling composition, mixing, placing, sampling, testing and maintaining bentonite/cement slurry; (2) supervision of alignment, verticality, and depth of soil mixing equipment; (3) controlling blending, mixing, sampling, and testing in-situ material; and (4) a thorough knowledge of soil mixing and cutoff wall construction equipment and material testing.

1.6 GENERAL CONDITIONS

1.6.1 Access and Ramps

Construct temporary access and ramps for work related to this section in accordance with Section 31 00 00 EARTHWORK

1.6.2 Protection of Existing Facilities

Conduct construction in a manner that avoids damage to all existing facilities that are not designated for removal or reconstruction.

Construction will occur during the normal growing and harvest season for surrounding agricultural fields. Construction must not interfere with the normal operation of existing irrigation canals, drainage ditches, and irrigation systems, except where required to install temporary water diversions if irrigation supply pipe crossings through the levee cannot be maintained in service during construction.

1.6.3 Construction Methods

Construct the cutoff wall using in situ deep mixing methods. Perform cutoff wall construction using a soil mixing rig which utilizes augers, shear plates, cutting heads, cutting posts or other devices capable of shearing and blending the in situ soil to a condition which meets the requirements of this section.

1.6.4 Sequencing of Work

Multiple work heading may be used to achieve the required schedule.

1.6.5 Water for Construction

See 01 50 02 TEMPORARY CONSTRUCTION FACILITIES

31 83 13 - 10

1.6.6 Obstructions

Culverts, standpipes, and other buried piping that are shown on the Drawings and that are either to be preserved and protected or removed and replaced as part of the work must not be considered obstructions. Existing utilities shown on the Ddrawings must not be considered obstructions.

Man-made objects encountered within the zone excavated to degrade the levee (e.g., utilities and other facilities, etc) must not be considered obstructions. The Contracting Officer must be the sole judge of whether an obstruction has been encountered. An obstruction will not be considered unless it is the result of natural ground conditions and when using properly operated and maintained equipment. Past performance will be considered when determining whether the equipment is properly operated and maintained, including but not limited to specific rig performance, tooling, and soil conditions, etc. For an obstruction to be considered as such, the rate of cutting head advancement after pre-drilling has already been applied to the potential obstruction zone must be less than:

a). 1 foot vertical advancement in 30 minutes for vertically installed elements, or b). 0.5 foot horizontal advancement in 30 minutes for horizontally installed elements.

1.6.7 Demonstration Section

Construct a cutoff wall test section prior to construction of the production cutoff wall. The test section must be 50 to 60 linear feet of cutoff wall. Proceed with production element construction after receipt of written test section acceptance by the Contracting Officer of the Quality Control and Acceptance for the Test SectionDemonstration Section from the Contracting Officer.

1.7 SITE CONDITIONS

See 02 02 00 SUBSURFACE DATA.

1.8 MAINTENANCE

1.8.1 Extra Materials

Maintain at the job site a sufficient quantity of raw materials and other supplies such that the work can proceed uninterrupted by material shortages. Modify the mix proportions and methods as needed to meet the required wall strength, permeability, continuity, and homogeneity and difficult subsurface conditions. Perform additional tests necessary to verify compliance with the Acceptance criteria.

PART 2 PRODUCTS

2.1 MATERIALS

2.1.1 Material Storage Facility

Provide all necessary materials, equipment and personnel to store the bentonite, cement and other additives under conditions to prevent moisture or other contaminants from interacting or mixing with the materials prior to use in the plant.

31 83 13 - 11

2.1.2 Cement

Cement must be Portland Cement Type I or Type II (per ASTM C150/C150M).

Provide a record copy cement supplier written certificate specifying cement quality. The Cement Certification submittal must correspond to the current source of cement. Submit statement(s) signed by an authorized official to certify on behalf of the manufacturer of the materials attesting that the products meet specified requirements. The statement must be dated after the award of the cContract, must state the Contractor's name, address, must name the project and location, and must list the specific requirements which are being certified.

2.1.3 Bentonite

Furnish a Bentonite Certification and a copy of the test reports from the bentonite supplier for each lot of bentonite shipped to the site stating that the bentonite complies with all applicable standards. The bentonite must be sodium cation base montmorillonite powder that conforms to API Spec 13A, Section 9. Bentonite must be new, pulverized, high-swelling natural sodium cation montmorillonite (Premium Grade Wyoming-type bentonite). Chemically treated bentonite will not be allowed. No bentonite from the bentonite manufacturer must be used prior to acceptance by the Contracting Officer. All bentonite must be subject to inspection, sampling, and verification of quality by Contractor QC testing and Government QA testing. Bentonite not meeting specifications must be promptly removed from the site and replaced with bentonite conforming to specification requirements at the Contractors expense. Protect bentonite from moisture during transit and storage. Submit statement(s) signed by an authorized official to certify on behalf of the manufacturer of the materials attesting that the products meet specified requirements. The statement must be dated after the award of the cContract, must state the Contractor's name, address, must name the project and location, and must list the specific requirements which are being certified.

2.1.4 Admixtures

Submit proposed use of admixtures, for to approval. Provide written documentation supporting the proposed use of all admixtures. Documentation must address the effects of the admixture on the cutoff wall SCB material, long-term stability and the admixture and the SCB material, and any potential effects on the natural environment. Admixtures must be proven with the trial design mixes. Use only admixtures approved by the Government. Retarders, fly ash, or other solids containing heavy metals are prohibited. Submit a Admixture Certification for each lot of admixtures.

2.2 WATER

2.2.1 Supply

See 01 50 02 TEMPORARY CONSTRUCTION FACILITIES

2.2.2 Quality

The water must be clean, fresh, and comply with the standards set below:

a). A pH equal to 7.0 plus or minus 1.0. Test Method API RP 13B-1 b). Total dissolved solids not greater than 500 parts per million. Test

31 83 13 - 12

Method EPA 600/4-79/020 Method 160.1.

c). Hardness less than or equal to 50 ppm. Test Method API RP 13B-1.

(Recommendation Only) d). VOCs less than the MCL. Test Method EPA 5030B/EPA 8260BEPA 5030B.

e). TPH less than the MCL. Test Method EPA Modified 8015.

f). Metals less than the MCL. Test Method EPA 3005A/EPA 6010C.

g). Pesticides less than the MCL. Test Method EPA 3510C/EPA 8081A/ EPA 8041A MCL = Maximum Contaminant Level

Water with hardness in excess of 50 ppm will be accepted for use based upon performance in the SCB mix as long as the required permeability standards specified herein for the in place SCB wall are achieved throughout the Pp roject. Furnish water quality test results for water used for mixing the bentonite slurry and cement slurry to assure conformance with the above limits. Water used for production must come from the same source as water used for the mix design. Abide by any and all Federal, State of California, and local regulations and other requirements governing such use. Include the cost of all related fees in the bid items pertinent to the work. Water must not be taken from the river for construction activities, except when required for testing and with the Contracting Officer's approval. Water taken from the river for testing purposes must only be filled by hand, and mechanical pumps are prohibited. Submit a Water Quality Test Report presenting the results of the testing.

PART 3 EXECUTION

This section describes the portion of the work to be performed. Furnish all plant, equipment, labor, and materials required to construct a cutoff wall as shown on the Ddrawings and Sspecifications.

3.1 MOBILIZATION

Mobilize equipment to the staging area after receiving approval from the Government.

3.2 PREPARATION

3.2.1 Preconstruction Submittals

Prepare the following preconstruction submittals and provided them within within 40 calendar days from the Notice to Proceed (NTP), except where otherwise indicated in the specification.

Production Plan

3.2.1.1 Operation Plan

Submit for approval the methods, schedule and sequence of operations for construction of the cutoff wall, including but not limited to site access, working platform construction, wall layout, waste management, offsite disposal locations, slurry preparation batching, mixing, and pumping and injection, and final grade closure. The schedule must also include information regarding equipment mobilization, equipment setup, 31 83 13 - 13 production/installation, and verification testing. Submit for approval the layout of operations including working pads and associated levee excavation, if required, for the construction of the wall. Include storage areas, slurry preparation and mixing areas, access corridor, and location and sizes of all stationary equipment.

3.2.1.2 Soil Mixing Equipment

Data on equipment to be used in all sequences of the cutoff wall construction, including mixing, placement, and equipment to be used in the CQC testing. Include the location of the laboratory trailer/structure.

Submit a detailed description of the equipment and procedures to be used during the project including, but not limited to, construction of the cutoff wall and monitoring the quality control parameters outlined herein, and collecting samples for laboratory testing. Procedures must include methods for locating the wall in the field and confirming that the wall is plumb. Also submit the proposed mix design and construction methods needed to comply with the drawings and specifications. The calibration of the bentonite and cement slurry mixing plants and blending of the bentonite and cement slurry must be documented. Include data on equipment such as mixers capable of producing both a stable colloidal suspension of bentonite slurry fully hydrated bentonite slurry; minimum 8 hrs or as determined by contractor during mix design development and cement slurry mixture;

storage facilities including tanks and methods of agitation; delivery methods and equipment; spillage, and containment facilities to control spillage.

3.2.1.3 Binder Delivery Methods and Equipment

Data on equipment such as mixers capable of producing a stable colloidal suspension of cement, bentonite slurry, or other mix combinations; storage facilities including tanks and methods of agitation; and delivery methods and equipment.

3.2.1.4 Qualification Submittal

Submit documentation supporting the requirements of QUALIFICATIONS.

Resumes must include dates, durations, projects and owners.

3.2.1.5 Sample Quality Control Records

Submit sample Quality Control Records. Include sample daily field reports, and laboratory test results.

3.2.1.6 Schedule and Sequence of Operations

Submit a proposed sequence of operations for the cutoff wall, showing schedule of demonstration section, headings, elements, etc..

3.2.1.7 Sequence Of Operations At Utility Line Crossings

Submit a proposed plan to accommodate utility crossing. This plan must be coordinated with the utility owner before submittal.

3.2.1.8 Sampling Plan

Submit a description of the procedures which will be used to obtain wet samples at the various depths required. A detailed drawing and written explanation of how the sampling mechanism operates must be provided.

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3.2.1.9 Cutoff Wall Surcharge Loading Plan

Submit a describingdescription of all surcharge loads applied to the cutoff wall during cutoff wall construction. This plan must show the distance between all surcharge loads applied and the top of the cutoff wall during cutoff wall construction. This plan must include the surcharge loads from materials and equipment and must compare the loads against the strength of completed work. This plan must also include surcharge loads from materials and equipment at approved equipment crossing points. This plan must also include requirements for minimum cover and/or additional protective measures for the completed cutoff wall.

3.2.2 Working Platform

Prepare the working platform of the levee section to a firm and essentially level condition for passage of machinery and equipment to the elevation shown in the Ddrawings. A berm, spoils trench or other appropriate type of barrier must be constructed within the construction limits to prevent off-site movement of waste materials, fluids, etc.

3.2.3 Determination of Impermeable Layer Depth

Perform soil borings using the sonic drilling method in accordance with ASTM D 6914 at 100 foot intervals along the cutoff wall centerline to determine the depth of the impervious stratum. Soil borings must begin in advance of the wall construction, and should be coordinated with the concurrent mix design program. The depth of the core must be a minimum of ten (10) feet below the bottom of the cutoff wall to be constructed. The core must be PQ diameter (minimum 3 inch).

The Contractor is to keep accurate logs and records of all borings and they are to be submitted to the Government within two (2) days after a boring is completed. Format for logs and record form must be reviewed by the Government prior to performing any work. All such logs/records must be recorded during the actual performance of the work and shall be preserved in good condition. The Government has the right to examine and review all such logs at any time prior their submittal and the right to request changes to the record keeping procedure for each bore hole. The following information shall be included on the logs for each hole:

a. Hole or number or designation and elevation of top of hole.

b. Driller's name and Geologist's or Engineers' name logging the hole.

c. Make, size, and manufacturer's model designation of drilling and equipment.

d. Hole diameter.

e. Dates and times when drilling operations were performed.

f. Time required for drilling.

g. Drill action, rotation speed, hydraulic pressure, water pressure, tool drops, and any other unusual and non-ordinary experience which could indicate the subsurface conditions encountered.

h. Classification and description by depth of the materials encountered using the Unified Soil Classification system (ASTM D2488) and including a description of color, moisture conditions, consistency or relatively density, and other appropriate descriptive information. This classification and description is to be made immediately after the samples are retrieved.

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i. Percentage of sample recovery per run.

j. Depth at which groundwater is encountered initially and when stabilized.

k. Depth of bottom of hole.

Logging of the borings are to be performed by a Geologist or Civil Engineer experienced in soil classifications and descriptions in accordance with ASTM D2488. The Government reserves the right to conduct independent classification of the samples collected in the field. A total of thirty

(30) sieve analyses (ASTM D422) and thirty (30) Atterberg limits (ASTM D4318 ) are to be performed on samples selected by the Government for the entire drilling program. The results of each soil boring will be logged by the Government. Unless destroyed by cutoff wall installation within 24 hours, Sonictest holes must be grouted with cement-bentonite grout in accordance with State of California and Yuba County standards. Contractor must retain all sonic core samples. Samples must be stored in wooden or metal core boxes after logging, and transported to the Government storage facility at 1645 Riverbank Road, West Sacramento, California. Allow and assist the Government to inspect the stored soil cores upon demand during the drilling process and before delivery to the Corps storage facility.

3.2.4 Rig Assembly

Assemble the rig in accordance with the approved Cutoff Wall Production Plan.

3.2.5 Grout Plant Assembly

Assemble the grout plant accordance with the approved Cutoff Wall Production Plan. The grout plant may be located within the work area or at any of the staging areas.

3.2.6 Rig Movement to Work Area

Move the rig to assembly area in accordance with all City or County standards with regarding to loading on roadways or bridges. Levee access roads may be used provided the equipment does not create an unstable ground condition.

3.3 MATERIAL DELIVERY AND INJECTION

Assemble the rig in the rig assembly area identified in the O Cutoff Wall Production PlanCutoff Wall Production Plan.

3.3.1 Deliveries

Deliver material to the site on a timely basis so as not to impede production. Ensure that traffic areas are kept free in traffic in advance of deliveries to prevent delays in production.

3.3.2 Silo Loading

Dry material must be stored in silos and fed to mixers for agitation and shearing. The air evacuated/displaced from the storage silos during the loading process must be filtered before being discharged to the atmosphere. In order to accurately control the water, bentonite, or cement mixing ratio, material mass must be weighed using the automatic batch scales in the mixing plant. Representative samples of the bentonite and cement must be obtained for each lot or truck load of material delivered to

31 83 13 - 16 the site. These samples must be stored in air tight containers until the cC ontract is complete, and must be used if needed, for testing to confirm material quality. Water quality must be tested once every two weeks.

3.3.3 Batching, Mixing and Agitation

Minimum and maximum mixing time must be as established during the test element production. The specific gravity of the bentonite/cement slurry must be determined during the design mix program for confirmation of bentonite/cement slurry proportions.

3.3.4 Pumping

Pump grout from the plant must be monitored continuously by an automated data acquisition system and by the Grout Plant Operator during all operations.

3.3.5 Air Injection

Injection of air may be approved. Document the use of air injection in the Cutoff Wall Production Plan. Monitor air pressure. Use gages mounted on the air compressor lines and soil mixing rig to monitor pressure.

Interruptions of return air stream must be restroked.

3.3.6 Injection

3.3.6.1 Leads

Inspect leads after each element is constructed to verify correct operation.

3.3.6.2 Ports

Inspect ports after each element is constructed to verify correct operation.

3.4 EQUIPMENT

3.4.1 Soil Mixing Apparatus

Use soil mixing equipment for this project. The augers, bits, teeth, sheet plates or cutting heads must be capable of thoroughly blending the in situ soils and bentonite slurry and cement slurry to the design depths. Use the proper tooling for the apparatus, including but not limited to tooling capable of operating in clay (including hardpan), silt, sand, gravel, and cobbles. Change cutting teeth, shear plates, augers, etc. as necessary to allow efficient advancement of the soil-mixing apparatus. Configure the equipment and/or element overlapping technique so that the length of the overlapping mixing elements extends for the full depth of the element and cutoff wall. The soil mixing method and apparatus must be sufficient to prevent soil inclusions greater than 3-inch maximum diameter from occurring within the element.

3.4.2 Electronic Sensors

The preset data in the on-board computer must be verified as correct for each section of wall and, if necessary, adjusted (e.g., installation depth, bentonite/cement slurry amount ratio, advancement rate, etc.). The operator must monitor and adjust the soil mixing apparatus speed as necessary during the wall milling and mixing process. All metering equipment must be calibrated at the beginning of the cutoff wall installation work and again

31 83 13 - 17 at the twenty-five percent project completion point, and every additional 25 percent increment (i.e., four calibrations during the project per rig).

The soil mixing Contractor must submit the calibration results to the Contracting Officer.The soil-mixing rig shall be equipped with electronic sensors built into the soil mixing apparatus to determine vertical alignment in two orthogonal directions: fore-aft and left-right. The sensors shall have a sensitivity of at least 1 part per 1000 (0.1 percent). The location of the sensors on the rig shall be painted to be easily identified from the ground. The hardware utilized to determine panel verticality shall be capable of measuring the deviation of one panel with respect to the adjacent panel at any incremental depth. The software accompanying the inclinometer hardware shall be capable of graphically displaying the incremental and total accumulated deviations with depth or elevation and be coded to alert the reader to any excess deviations. The output from the sensors shall be routed to a readout and data storage device and a display on the rig console that is visible to the operator and the Contracting Officer during penetration and withdrawal. The inclination of the soil mixing apparatus shall be continuously monitored and recorded. The recorded data shall be available in table and graphic form such that the inclination and position of the as-built panel with respect to vertical and the adjacent panel can be easily determined.

3.4.3 Penetration Depth Marking

The soil mixing equipment (e.g., kelly bar, mast, post, etc.) must be adequately marked to allow a visual determination that the correct depth of penetration has been reached.

3.4.4 Cement/Bentonite Slurry Plant

Bentonite Slurry and Cement Slurry must be pre-mixed in a mixing plant, which combines dry materials and water in predetermined proportions. The mixing plant must consist of a cement slurry mixer, a bentonite slurry mixer, agitator, pump, batching scales, and a computer control unit.

Positive displacement pumps, or other suitable pumps as approved by the Contracting Officer must be used to transfer the slurry from the mixing plant to the soil-mixing apparatus. The slurry must be delivered to each auger by an individual pump. All aspects of the batching and pumping operations must be continuously monitored and recorded electronically. The batching and pumping record must be produced for each element.

3.4.5 Replacement Parts

Maintain at the job site a supply of spare replacement parts and backup equipment sufficient to allow the soil-mixing cutoff wall construction to proceed without undue interruption due to mechanical breakdown or equipment failure.

3.5 INSTALLATION

3.5.1 Demonstration Section

A Ddemonstration Ssection is required before production work is permitted to proceed.

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3.5.1.1 Location

The Demonstration Section must consist of 50 to 60 linear feet of cutoff wall. The demonstration section must be located within Cutoff Wall B Alignment between alignment Stations 9+00 and 18+07. The depth of cutoff wall in the demonstration section must be at least the same depth for the production cutoff wall. Establish the cement and bentonite dosage and mixing index in the test section.The demonstration section must consist of 50 to 60 linear feet of cutoff wall. The demonstration section must be located within the cutoff wall alignmentand as approved by the Government.

The depth of cutoff wall in the demonstration section must be at least the same depth for the deepest part of the production cutoff wall. Establish the cement and bentonite dosage and mixing index in the demonstration section.

3.5.1.2 Mix Design Development

Begin the trial mix designs within seventhirty (30) calendar days from the Notice to Proceed (NTP). Develop a laboratory testing program to demonstrate the adequacy of the proposed SCB mix design. The test materials must be taken from materials collected from at least three separate locations within the limits of the cut off wall; however, Ff abricate a sufficient number of samples and trial mix designs to support the basis for the proposed mix design. The trial mix designs must cover a range of percentages of bentonite, cement, and admixtures to correlate to the more granular anticipated ranges of soil gradations. The minimum number of mix designs must be four. The materials used to fabricate the test specimens must be those proposed for use in construction including (iI f proposed) site foundation soil and, bentonite, cement, water from the proposed project's source, admixtures, and any other materials may be used .

The performance criteria must include permeability, and unconfined compressive strength in accordance with the parameters and methods described hereinof this specification. Provide a mix design for each segment of the cutoff wall where the mix design is applicable.

The Cutoff Wall SCB Material Mix Design and SCB Mix Design Test Report must include the design of the SCB mix including the materials gradation and material sources, water sources, mix proportions, and design gradation ranges and the test sample gradations, slumps, densities, permeabilities, unconfined compressive strength, and moisture contents. RSubmit results of at least three permeability and three unconfined compressive strength tests at each testing age (7, 14, and 28 days for permeability and 3, 7, 14, and 28 days for unconfined compressive strength) of each final SCB mix using the SCB materials proposed, fully satisfying the performance criteria, must be submitted. AProvide adjustments to the mix design during construction must be provided to the Contracting Officer before use, and must document the location of each different mix on the Aas-Bbuilt profile.

Submit the Demonstration Section test report for approval a maximum of 60 calendar days from the Notice to ProceedNTP execution date and a minimum of 45 calendar days prior to the initial cutoff wall construction (Demonstration Section). Do not proceed with test element construction before acceptance of the test report.

3.5.1.3 Establishment of Mixing Index

Prior to full scale production of the soil-mixed wall, prepareconstruct a

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Test SectionDemonstration Section to verify that the required permeability and strength can be achieved by the selected mix design, and that the installation methods provide adequate mixing, homogeneity, and continuity, for the existing field conditions at the project sites. Construct a Test Section. Incorporate tThe Test SectionDemonstration Section may be incorporated into the permanent cutoff wall if it meets all the requirements for the production wall, subject to Government Approval. In addition to determining the proportions of bentonite, cement, soil, and water to be utilized during production, tThe Test SectionDemonstration Section is to be used to determine the proportions of bentonite, cement, soil, water, slurry injection rate, soil-mixing apparatus rotation speed and penetration/withdraw or advancement rate (as applicable to method), and time delay between completion of a primary elements and beginning of an overlapping secondary element. Once established, these parameters which will be used during installation of the production wall. Submit the Soil Mixing Operation Plan containing the selected mix design, and established mixing index (Im) which will be used for the project.

The mixing index for each method is as follows:

a. Wet Rotary Shaft (WRS)

Im = M (Np/Vp + Nw/Vw)

Where M is the total number of mixing blades, Np and Nw are the rotational speed of axis during penetration and withdrawal in rev/min, and Vp and Vw are the velocity of the mixing apparatus penetration and withdrawal.

b. Wet Rotary End (WRE) and Wet Rotary and Jet End (WJE)

Im = (Np/Vp + Nw/Vw)

Where Np and Nw are the rotational speed of axis during penetration and withdrawal in rev/min, and Vp and Vw are the velocity of the mixing apparatus penetration and withdrawal.

Wet Vertical Panel (WVP)

Im = Nc(Vc/Va)

Where Nc is the number of revolutions per minute of the cutting chain during advancement of 1 ft, Vc is the speed of the chain, and Va is the advancement rate of the cutting head/rig.

3.5.1.4 Core Drilling and Virtual Cores

After 28 days (minimum) and before 56 days (maximum) of curing of the cutoff wall, perform four (4) vertical borings at locations selected by the Government. The borings will be drilled to an elevation not less than five

(5) feet above the as-built invert elevation of the bottom of the cutoff wall at each respective location drilled. The borings must meet the

31 83 13 - 20 following requirements.

a). DRILLING METHODDrilling method: The drilling method the triple barrel wireline coring system.

b). CORE SIZECore size: Use PQ core drilling size.

c). DRILLING FLUIDdrilling fluid: Select A drilling fluid such as to maximize viewing of the inside of the bore hole with the optical televiewer probe. The Government evaluation will consider borehole viewing when approving or rejecting drilling fluids.

d). DRILL RIG POSITIONINGDrill rig positioning: Use surveying methods to position the drill rig at the test location selected by the Government. Position the drill core at the top surface of the cutoff wall to within one-tenth (0.1) of a foot horizontal of the proper location. After the drill rig has been properly positioned, proceed with boring e). BOREHOLE PREPARATIONBorehole preparation: The borehole must be sufficiently clean to provide a viewable surface given the optical televiewer characteristics. The borehole must be cleaned with a solution of five (5) percent sodium hypochlorite using water from a source previous approved by the Government. Clean the borehole before the downhole probe is run through the borehole.