31_32_23.16_08_-_Amendment_0009.pdf

East Branch Dam, Dam Safety Modification, Cutoff Wall

SECTION TABLE OF CONTENTS

DIVISION 31 - EARTHWORK

SECTION 31 32 23.16 08

SLURRY CONTROL DRILLING AND GROUTING

PART 1 GENERAL

1.1 SCOPE

1.2 DEFINITIONS

1.2.1 Slurry Control Grouting

1.2.2 Series

1.2.3 Split Spacing

1.2.4 Initial Primary Hole

1.2.5 Primary Hole

1.2.6 Secondary Holes

1.2.7 Tertiary Holes

1.2.8 Succeeding Series

1.2.9 Section

1.2.10 Zones

1.2.11 Pull

1.2.12 Run

1.2.13 Stage

1.2.14 Stop

1.2.15 Lugeon

1.2.16 Modified Lugeon

1.2.17 Apparent Lugeon

1.2.18 Refusal

1.2.19 Closure

1.2.20 Downstage Grouting

1.2.21 Upstage Grouting

1.2.22 Communication

1.2.23 Top of Rock

1.2.24 Soil

1.2.25 Drill Setups

1.2.26 Grout Setups

1.2.27 Packer Settings

1.2.28 Instrumented Packer Assembly

1.2.29 Gauge

1.2.30 Intermittent Grouting

1.2.31 Balanced Stable Grout

1.2.32 Effective Grouting Pressure

1.2.33 Holding Pressure

1.2.34 Back Pressure

1.2.35 Critical Area

1.3 MEASUREMENT AND PAYMENT

1.4 REFERENCES

1.5 SUBMITTALS

1.6 MATERIALS DELIVERY, STORAGE, AND HANDLING

1.6.1 Grout Materials

1.6.2 Care and Delivery of Core

1.7 GEOTECHNICAL SITE CONDITIONS

SECTION 31 32 23.16 08 Page 1

W911WN-13-R-0002 REVISED BY AMENDMENT 0009

1.8 QUALIFICATIONS

1.8.1 Lead Grouting Geologist/Geotechnical Engineer Credentials

1.8.2 Automated Grouting Control and Data Collection System Operator

Credentials

1.8.3 Drill Rig Operator Credentials

1.8.4 Lead Geologist/Geotechnical Engineer Credentials

1.8.5 Drilling Inspector Credentials

1.8.6 Surveyor Credentials

1.9 ON-SITE DAM SAFETY TRAINING

1.10 SEQUENCE AND SCHEDULING

1.10.1 General

1.10.1 Restrictions

1.11 WASTE MANAGEMENT

1.12 PERMITS, CERTIFICATIONS, AND LICENSES

PART 2 PRODUCTS

2.1 GROUTING MATERIAL

2.1.1 Water

2.1.2 Cement

2.1.3 Pozzolans

2.1.4 Admixtures

2.1.4.1 Water Reducer

2.1.4.2 Superplasticizer

2.1.4.3 Viscosity Modifier

2.1.4.4 Fluidifier

2.1.4.5 Anti-Washout Admixture

2.1.5 Bentonite

2.1.6 Sand

2.1.7 Chemical Water Clarifier

2.2 CORE BOXES

PART 3 EXECUTION

3.1 EQUIPMENT

3.1.1 General

3.1.2 Drilling Equipment

3.1.3 Grouting Equipment

3.1.3.1 Instrumented Packer Assembly System

3.1.3.2 Grout Plant

3.1.3.3 Automated Grouting Control and Data Collection System

3.2 GROUT AND VERIFICATION HOLE DRILLING

3.2.1 General

3.2.1.1 Drilling Logs

3.2.2 Grout Line Locations, Inclinations, and Depths

3.2.3 Tolerances and Deviations

3.2.4 Standpipe

3.2.5 Rock Drilling

3.2.6 Verification Drilling

3.2.7 Borehole Imaging

3.3 GROUTING PROCEDURES

3.3.1 General

3.3.2 Backfilling

3.3.3 Downstage Grouting

3.3.4 Upstage Grouting

3.3.5 Initial Primary and Primary Holes

3.3.6 Successive Holes

3.3.7 Split spacing

3.3.8 Retreatment

SECTION 31 32 23.16 08 Page 2

3.3.9 Completion of Section

3.3.10 Communication

3.3.11 Instrumented Packer Use

3.3.12 Pressure Washing

3.3.13 Water Pressure Testing

3.3.14 Grouting Progress

3.3.15 Grouting Pressures

3.3.16 Grout Mixes

3.3.16.1 Grout Testing and Inspection

3.3.16.2 Measurement Equipment

3.3.16.3 Mixing Procedure

3.3.16.4 Grout Injection

3.3.16.5 Grout Temperature

3.3.17 Equipment Arrangement and Operation

3.3.18 Personnel Communication System

3.4 DRILLING AND GROUTING RECORDS

3.4.1 Drilling Spreadsheet

3.5 SLURRY CONTROL DRILLING AND GROUTING FINAL REPORT

-- End of Section Table of Contents --

SECTION 31 32 23.16 08 Page 3

SECTION 31 32 23.16 08

SLURRY CONTROL DRILLING AND GROUTING

PART 1 GENERAL

1.1 SCOPE

This specification describes the requirements for the slurry control grouting procedure and sequence. If slurry control grouting is used, and during grouting operations, the Contracting Officer reserves the right to direct the grouting operation when necessary to maintain dam safety or to achieve specific results. This section discusses Slurry Control Grouting required to provide slurry and fluid loss prevention during cutoff wall construction at the locations, limits, and details as shown on the contract drawings. Therefore, slurry control grouting will not be required for cased cutoff wall excavation methods where the casing is embedded a minimum of 10 feet into rock. If the Contractor does not use a cased method or uses a cased method that does not achieve at least 10 feet embedment into rock, then Slurry Control grouting will be required and grouting shall be included in the test section per Section 31 56 10.00 08 CUTOFF WALL CONSTRUCTIONS. Specifications include drilling of soil and rock, washing and pressure testing grout holes; verification holes; borehole imaging;

grout materials and testing, making grout connections; furnishing, handling, transporting, storing, mixing and injecting the grouting materials; care and disposal of drill cuttings, waste water and waste grout; clean up of the areas upon completion of the work and all other such operations as are incidental to the drilling and grouting.

The Contractor is required to provide and operate an Automated Grouting Control and Data Collection System (AGCDCS) to record, display and control the grouting and water pressure testing of this contract. Prior to grouting, the Contractor is required to develop a suite of balanced-stabilized grout mixes that meet the requirements specified herein. The Contractor's methods shall safely treat the rock and foundation soils, particularly the soil/rock interface. The Contractor shall limit the amount of fluid or grout being introduced into the embankment, foundation soils, and interface. The Contractor shall take the necessary precautions to prevent hydrofracturing or jacking due to back pressure.

Drilling, water pressure testing and grouting shall follow the sequence of work presented in the Contractor's Slurry Control Drilling and Grouting Work Plan and approved by the Contracting Officer. Adherence to the schedule and sequence directed by the Contracting Officer will not be seen as cause for time extension or claims for additional costs beyond those specified herein.

Drilling through soil and rock shall be performed in accordance with the requirements of 02 32 00 SUBSURFACE DRILLING, SAMPLING, AND TESTING, unless otherwised noted herein. The Contractor will be responsible for any other operations required to facilitate this work such as traffic control and environmental compliance.

SECTION 31 32 23.16 08 Page 4

1.2 DEFINITIONS

1.2.1 Slurry Control Grouting

If any method other than a cased method taken 10 feet into rock is to be used for cutoff wall excavation, Slurry Control grouting will be required to prevent slurry or fluid loss during cutoff wall excavation and construction along the length of the cutoff wall. A double row grout curtain with a minimum grout hole spacing, drilled and grouted to 5 vertical feet below the bottom of the cutoff wall, shall be performed on a series of boreholes by stages, using the methods described herein and as directed by the Contracting Officer to achieve required refusal and closure criteria.

1.2.2 Series

A series is defined as a group of boreholes grouted in succession such that the higher order holes precede the lower order holes. The Initial Primary series precede Primary series, Primary series precede Secondary series, Secondary series precede Tertiary series, and so on.

1.2.3 Split Spacing

Split spacing is the procedure of locating an additional grout hole midway between two previously drilled and grouted holes that have exceeded a threshold grout take. Split spacing criteria may vary depending on the stage, series, or section that is under consideration.

1.2.4 Initial Primary Hole

Initial Primary holes will be required to be drilled and grouted on 80 foot spacing prior to Primary hole drilling and grouting within a section.

1.2.5 Primary Hole

Primary holes will be required to be drilled and grouted on 20 foot spacing prior to succeeding Secondary hole drilling and grouting within a section.

1.2.6 Secondary Holes

Secondary holes shall split space Primary holes. Drilling and grouting of Secondary holes shall be completed within a section prior to succeeding series drilling and grouting within that section.

1.2.7 Tertiary Holes

Tertiary holes, if required, shall split space Primary and Secondary holes. Drilling and grouting of Tertiary holes shall be completed within a section prior to succeeding series drilling and grouting within that section.

1.2.8 Succeeding Series

Each of the succeeding series of holes shall be located based on the split space criteria. Holes beyond Tertiary level will be named "Quaternary", followed by "Quinary". The final depths of subsequent holes will be determined from the contract drawings or approved by the Contracting Officer.

SECTION 31 32 23.16 08 Page 5

1.2.9 Section

A section is an 80 foot length along a grout line between two Initial Primary holes. Simultaneously drilling and grouting in different sections shall not be closer than 80 feet. In the 80-foot section no more than one hole shall be simultaneously drilled and/or grouted.

1.2.10 Zones

The length of a borehole drilled for grouting will be divided into different zones based on the process used for drilling and grouting.

Zone 1 shall extend from the bottom of the casing to a distance of 15 feet measured along the borehole length (as opposed to vertically).

Actual length of Zone 1 may be adjusted by the Contracting Officer based upon rock conditions, drilling fluid loss or gain, and water pressure test results.

Zone 2 extends from the bottom of the Zone 1 to the final required depth of the grout hole.

1.2.11 Pull

A pull is a single retrieval of the core barrel from the borehole, after a run, regardless of whether the core barrel is full or not.

1.2.12 Run

A run is a single advance of the core barrel into the ground to add the next length of drill rods to continue drilling.

1.2.13 Stage

A stage is one complete operational cycle of drilling, cleaning, water pressure testing, grouting, and grout cleanout. The actual depth of a stage will depend upon geologic conditions and water pressure test results, may vary from a fraction to the full intended depth of the stage, and is marked by the loss or gain of drill water in appreciable amounts. Grouting shall be conducted in intervals no greater than twenty (20) feet and pressure testing shall be conducted in intervals no greater than ten (10) feet measured along the length of the hole.

1.2.14 Stop

A stop is a predetermined depth at which the packer is positioned.

1.2.15 Lugeon

Lugeon value refers to the permeability of the formation. Specifically, a Lugeon unit is defined as a flow of 1 liter of water per minute per meter of borehole length at a pressure of 10 bars.

1.2.16 Modified Lugeon

A modified Lugeon is a permeability value corrected for a pressure lower than the 10-bar pressure defined for the Lugeon. Inasmuch as the pressures anticipated for this work are below 10 bars, the Modified Lugeon shall be the normal unit of measure; and for convenience shall be referred to as a Lugeon.

SECTION 31 32 23.16 08 Page 6

1.2.17 Apparent Lugeon

Apparent Lugeon refers to the grouting permeability of the formation, using a grout that behaves as a Bingham fluid with a known apparent viscosity.

The evolution of the Apparent Lugeon value during grouting shall govern the variation of the grout mix and other injection parameters. The Apparent Lugeon will be monitored in real time by the Automated Grouting Control and Data Collection System during grouting. The Apparent Lugeon shall be corrected for pressure, flow, and mix as appropriate.

1.2.18 Refusal

Refusal is the completion of a stage by grouting less than a prescribed rate for 5 minutes. Refusal for Slurry Control Grouting is defined as 0.75 gallons per minute injection at the maximum allowable pressure held for 5 minutes. Refusal of gravity grouted stages is defined as maintaining the level of grout at the surface elevation for one hour. The Contracting Officer may modify the refusal definitions based on the conditions encountered as the work progresses. Refusal shall be met for each hole for each stage being grouted prior to drilling and grouting additional holes within a section. The refusal criteria may vary depending on the stage, series, or section that is under consideration, and may be modified by the Contracting Officer as work progresses.

1.2.19 Closure

Closure is defined as the completion of all grouting within a section as evidenced by the fact that none of the previous series of split spaced holes exceed the established threshold for additional split spaced holes.

Closure is determined from Lugeon values of all stages and confirmed by verification drilling. Closure criteria for Slurry Control Grouting is a Lugeon value of 10 Lugeons or less or cessation of grouting directed by the Contracting Officer.

1.2.20 Downstage Grouting

Downstage grouting is a protocol involving drilling and grouting of a stage before drilling the next deeper stage within the same borehole. Downstage grouting shall be required for Zone 1 of grouting in each hole and where directed by the Contracting Officer.

1.2.21 Upstage Grouting

Upstage grouting is a protocol wherein a borehole is drilled to a final depth and grouted in a sequence beginning at the bottom-most stage and progressing upward and shall be used for Zone 2 of grouting.

1.2.22 Communication

Communication is the passage of water or grout from one hole to another or to any opening during the course of drilling, water pressure testing, and/or grouting.

1.2.23 Top of Rock

Top of rock is defined as the first encounter of consolidated or weathered bedrock including sandstone, siltstone, limestone, or shale layer as drilling proceeds from the ground surface to the bottom of the grout

SECTION 31 32 23.16 08 Page 7 curtain as determined by a Government Geologist. Boulders within the soil column are not considered top of rock.

1.2.24 Soil

Soil is defined as all earthen materials, both natural and placed, above top of rock including sands, silts, clays, gravels, boulders and cobbles.

1.2.25 Drill Setups

Drill setups are defined as the procedure to position and align the drill rig on the grout hole for the purpose of drilling.

1.2.26 Grout Setups

Grout setups are defined as the procedure to setup and align the header/cart on the grout hole for the purpose of water pressure testing or grouting.

1.2.27 Packer Settings

Packer settings are defined as the positioning and inflation of a packer for the purpose of injecting grout.

1.2.28 Instrumented Packer Assembly

An instrumented packer assembly measures total pressures during water pressure testing and grouting either a) between the base of the packer and the bottom of the borehole, b) between the packers of a double-packer assembly, or c) immediately above the packer. The assembly is part of a system that indicates total pressure in real-time by monitor display, and records pressure data for later comparison with the water pressure and grouting pressure versus time. The effective pressure can be determined by subtracting the initial water pressure from the measured total pressure.

The instrumented packer assembly system is to be used in 100 percent of the grout holes requiring pressure grouting and water pressure testing unless otherwise directed by the Contracting Officer.

1.2.29 Gauge

A gauge is an instrument used to measure the grouting pressure at various locations from the plant to the drill hole collar.

1.2.30 Intermittent Grouting

Intermittent grouting is the process whereby the Contracting Officer directs that grouting cease after either 1) a certain volume of grout has been pumped into a stage, or 2) a period of time of pumping grout has been expended. Then one of two options will occur:

Option 1) The Contractor will be directed to cease grouting to allow the grout placed in the stage to harden. The length of time will depend on grout properties and set time. At that point, the Contractor may then re-drill the stage and attempt to re-grout the stage. The Contractor shall plan work so that he can move and grout in other holes while waiting for the grout to set.

Option 2) After ceasing grouting, have a period of time to allow the grout placed to reach initial gel, followed by re-setting the packer to

SECTION 31 32 23.16 08 Page 8 the same stage and the Contractor will then attempt to re-grout the stage. The Contractor shall plan work so that he can move and grout in other holes while waiting for the grout to set.

1.2.31 Balanced Stable Grout

A grout mixture that is a homogenous, balanced blend of water and cement combined with selected additives and admixtures to produce a product that experiences minimal to no bleed and maintains a constant rheology (viscosity, cohesion, pressure filtration) during placement.

1.2.32 Effective Grouting Pressure

Effective grouting pressure shall be calculated based on pressures in the grouting zone, considering in situ water pressure, weight of grout column, and estimated head losses and shall be measured in the ground with the use of an instrumented packer. The effective pressure at the instrumented packer sensor can be determined by subtracting the initial water pressure from the measured total pressure. To obtain the effective pressure at the middle of the stage, the static pressure from the ground water and grout between the sensor and the middle of the stage elevation will need to be considered.

1.2.33 Holding Pressure

Holding pressure shall be measured and recorded for each stage. When grouting is complete, shut the valve off above the gage and record the rate at which the gage goes back to zero or stops at a lesser pressure than the grouting pressure. If the hole has been completely grouted, the holding pressure will slowly go to zero or will hold at a pressure less than the grouting pressure; if the hole has not been fully grouted, the holding pressure will drop very quickly to zero. If there is no holding pressure, there is a problem that will require investigation by the Contractor.

1.2.34 Back Pressure

Back pressure is measured to determine if jacking or fracturing occurred during grouting. To measure back pressure, shut off the valves above and below the gage, drain the gage with the bleeder valve to zero and close the bleeder valve, then open the bottom valve from the hole. If there is any measurable pressure, then the grout is returning to the surface of the hole and jacking (if in the rock), or fracturing (if in soil), may have occurred. Back pressure shall be measured and recorded for each stage.

1.2.35 Critical Area

The critical area is a section of the cutoff wall alignment between Stations 7+70 and 8+80 where the Contractor shall use special precautions during construction. The critical area consists of the zone around the 1957 grouted void. The materials in the Critical Area include but are not limited to hardened grout materials, loose wet soils, compacted silts and sands, and pockets of voids, as described in Volume 2 - 2012 Geotechnical Baseline Report.

1.3 MEASUREMENT AND PAYMENT

All work and associated costs of work specified herein shall be measured and paid for in accordance with the section 01 22 00.00 10 MEASUREMENT AND PAYMENT. Payment will constitute full compensation for all work including

SECTION 31 32 23.16 08 Page 9 equipment, labor and materials. All work not specifically identified in the pay items will be considered incidental to the pay items and will not be paid for separately

1.4 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; 4th Ed) Recommended Practice for Field Testing Water-Based Drilling Fluids

ASTM INTERNATIONAL (ASTM)

ASTM C109/C109M (2011b) Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2-in. or (50-mm) Cube Specimens)

ASTM C123/123M (2012) Standard Test Method for Lightweight Particles in Aggregate

ASTM C117 (2004) Standard Test Method for Materials Finer than 75-um (No. 200) Sieve in Mineral Aggregates by Washing

ASTM C1240 (2011) Standard Specification for Silica Fume Used in Cementitious Mixtures

ASTM C128 (2012) Standard Test Method for Density, Relative Density (Specific Gravity), and Absorption of Fine Aggregate

ASTM C136 (2006) Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates

ASTM C142/C142M (2010) Standard Test Method for Clay Lumps and Friable Particles in Aggregates

ASTM C150/C150M (2012) Standard Specification for Portland Cement

ASTM C1602/C1602M (2012) Standard Specification for Mixing Water Used in Production of Hydraulic Cement Concrete

ASTM C191 (2008) Standard Test Method for Time of Setting Hydraulic Cement by Vicat Needle

ASTM C31/C31M (2012) Standard Practice for Making and Curing Concrete Test Specimens in the Field

ASTM C39/C39M (2012) Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens

SECTION 31 32 23.16 08 Page 10

ASTM C494/C494M (2012) Standard Specification for Chemical Admixtures for Concrete

ASTM C617/C617M (2012) Standard Practice for Capping Cylindrical Specimens

ASTM C618 (2012) Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete

ASTM C70 (2006) Standard Test Method for Surface Moisture in Fine Aggregate

ASTM C87/C87M (2010) Effect of Organic Impurities in Fine Aggregate on Strength of Mortar

ASTM C937 (2010) Grout Fluidifier for Preplaced-Aggregate Concrete

ASTM C938 (2010) Proportioning Grout Mixtures for Preplaced-Aggregate Concrete

ASTM C939 (2010) Flow of Grout for Preplaced-Aggregate Concrete (Flow Cone Method)

ASTM C940 (2010a) Expansion and Bleeding of Freshly Mixed Grouts for Preplaced-Aggregate Concrete in the Laboratory

ASTM D6910/D6910M (2009) Standard Test Method for Marsh Funnel Viscosity of Clay Construction Slurries

U.S. ARMY CORPS OF ENGINEERS (USACE)

COE CRD-C 100 (1975) Method of Sampling Concrete Aggregate and Aggregate Sources, and Selection of Material for Testing

COE CRD-C 120 (1994) Test Method for Flat and Elongated Particles in Fine Aggregate

COE CRD-C 61 (1989A) Test Method for Determining the Resistance of Freshly Mixed Concrete to Washing Out in Water

COE CRD-C 661 (2006) Specification for Antiwashout Admixtures for Concrete

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

SECTION 31 32 23.16 08 Page 11

Drilling Equipment; G, DG

Grouting Equipment; G, DG

Automated Grouting Control and Data Collection System; G, DG

Refer to Section 31 09 14 DATA MANAGEMENT SYSTEM for description.

Slurry Control Drilling and Grouting Work Plan; G, DG

Not less than 60 Days prior to the commencement of drilling slurry control grout holes, the Contractor shall submit a Slurry Control Drilling and Grouting Work Plan that shall include, but not be limited to a working schedule of activities; a personnel chart identifying key personnel, points of contact and their responsibilities; a detailed list of equipment and materials to be used; plan view diagram identifying features of the work area including trailers, grout plants, storage areas, staging areas and grout curtain details including grout hole layout in plan and section that shall present locations and depths of all grout and verification holes; proposed sequence and procedures for all aspects of drilling, flushing, water pressure testing and grouting.

The Contractor has been provided a layout of the baseline coordinates of general location of historical grouting programs and explorations as part of the Volume 2 - 2012 Geotechnical Baseline Report. A pattern for drilling primary and secondary holes is shown in the drawings and slurry control grouting criteria described in this section.

The Slurry Control Drilling and Grouting Work Plan shall include the Contractor's method of treating boulder, cobble, and gravel zones in the embankment and foundation soils as needed and particularly the soil/rock interface.

The Slurry Control Drilling and Grouting Work Plan shall include details of the sequence of overburden casing, coring and drilling of verification and grout holes, anticipated staffing and shifts, identification of key milestones and a list of assumptions and a discussion of their potential impacts on the course of work. Any changes in the grout hole orientations or additional grout lines needed at the bend of the groutline to the dogleg in order to prevent any windows for slurry loss shall be described in the work plan.

Also included in the Slurry Control Drilling and Grouting Work Plan shall be general guidelines and procedures for identifying and isolating zones of grout take and procedures to be followed in the event of communication in grout holes, thickening and thinning mixes, the means of providing thicker or thinner mixes expeditiously to the grout hole, the procedures used to minimize wasted grout, and testing procedures.

If a slurry system is used for cutoff wall excavation support, the Slurry Control Drilling and Grouting Work Plan shall include all the above listed items for the Slurry Control Grouting drilling and grouting activities. The Contractor is responsible for providing additional drill holes and grouting to meet permeability

SECTION 31 32 23.16 08 Page 12 requirements to control for slurry loss. Additional holes and grouting will be measured and paid for using the line items described under 01 22 00.00 10 MEASUREMENT AND PAYMENT.

Water Pressure Testing; G, DG Drilling and Grouting Records; G, DG

The Contractor shall submit examples of the water pressure testing and grouting records as well as grouting records with mix changes produced by the Automated Grouting and Data Collection System and the Instrumented Packer Assembly System not less than 30 days prior to the commencement of drilling grout holes.

SD-03 Product Data

Permits, Certifications, and Licenses

The Contractor shall submit copies of all required permits, certifications and licenses required by Federal, State, and local law for the execution of this work.

Equipment

A list, details and data on the drilling, pressure washing, pressure testing, grouting equipment and materials shall be submitted for conformance with the requirements of paragraph EQUIPMENT. Equipment details shall include but not be limited to instrumented packers, gages, transducers, borehole deviation survey equipment, pumps, hoses, drills, drill bit size and type, stabilizers, and any equipment that will impact the quality of the work, calibration methods for gages, flow meters, and head loss plots at various pressures and flow rates for the grouting system, and any additional equipment details requested by the Contracting Officer.

Grouting Material; G, DG

A detailed list of the cement, pozzolans, admixtures, and sand shall be submitted and approved in advance of grout mix design and shall include the source, manufacturers' descriptive literature, compliance certificates with associated standards, and Material Safety Data Sheet (MSDS) of all components of grouts used in the work. The submittal shall include current mill tests for cement and pozzolans, and aggregate quality testing for the sand. The Government shall have 30 days to review materials for approval.

Grout Plant; G, DG

Detailed plans and specifications shall be submitted showing equipment and grout plants layout proposed for batching, mixing, and placing grout not less than 30 days prior to grouting. The storage location, testing location, storage method, and quantity of each material required in the mix designs for short term or indefinite grouting situations shall be included.

SD-06 Test Reports

Drilling Logs; G, DG

SECTION 31 32 23.16 08 Page 13

System Calibration Reports

The Contractor shall provide weekly calibration reports for the Automated Grouting Control and Data Collection System, grouting equipment, and all related equipment starting not less than 30 days prior to the commencement of using the equipment and every month afterwards. The reports shall site the order of accuracy and frequency of calibration. Reports shall include photos of the instruments on the equipment and copies of the raw numeric data collected in Microsoft Excel spreadsheet, manufacturer's specifications and certificate, instrument ranges, distributor's calibration instructions, and plots generated.

Grout Mixes; G, DG

Details including all components, proportions, mixing procedures and sequence of additives and admixtures of proposed grout mixes shall be submitted after grouting materials have been approved including any additional mixes as approved. This submittal shall be completed in accordance with Section 01 33 16.00 08 CONTRACTOR SUBMITTALS REQUIRING ENGINEERING AFTER AWARD. The Government shall have 30 days to review mix design for approval before initiation of grouting may commence. Test results for viscosity, specific gravity, set times (initial and final), strength (at 3, 7, 14, and 28 days), bleed, shrinkage, and other testing as required in paragraph Grout Mixes shall also be submitted, including the testing standard used for each test

Material Test Reports; G, DG

Material test reports showing that the various grouting materials meet the quality and soundness requirements specified shall be submitted 90 days prior to submittal of the grout mixes.

The reports shall include mill tests for cement and pozzolans, and aggregate quality testing.

Water Testing for Water Used in Grouting; G, DG

Contractor shall submit test results prior to starting grout work and quarterly demonstrating the water source has no deleterious effect on the grout quality. These tests shall be in accordance with ASTM C1602/C1602M for non-potable water only.

Grout Tests; G, DG

The Contractor shall submit results of daily, weekly, and monthly Contractor Quality Control grout tests. The Contractor shall submit, on a weekly basis, all quality control grout tests-cumulative through the entire job. All results shall be stored in the Data Management System. A weekly summary report shall be submitted in an electronic format.

Drilling Spreadsheet; G, DG

The Contractor shall furnish a table for each hole containing the information specified in paragraph Drilling Spreadsheet.

SD-07 Certificates

SECTION 31 32 23.16 08 Page 14

Automated Grouting Control and Data Collection System Operator Credentials; G, DG

Refer to Section 31 09 14 DATA MANAGEMENT SYSTEM for description

Lead Grouting Geologist/Geotechnical Engineer Credentials; G, DG

The Contractor shall submit the name and qualifications of the Professional Geologist(s) or Geotechnical Engineer(s) not less than 30 days prior to commencement of drilling activities.

Changes in personnel will require additional submittals for approval of these key personnel.

Drill Rig Operator Credentials; G, DG

The Contractor shall submit the name and qualifications of the Driller(s) and Drilling Inspector(s) not less than 30 days prior to commencement of drilling activities. Changes in personnel will require additional submittals for approval of these key personnel.

Lead Geologist/Geotechnical Engineer Credentials; G, DG

Drilling Inspector Credentials; G, DG

Surveyor Credentials; G, DG

On-Site Dam Safety Training; G, DG

The Contractor shall submit proof of completion of on-site Dam Safety Training provided by the USACE for all Drillers, Drilling Inspectors, Grout Operators, Geologists and Geotechnical Engineers staffed in the field.

SD-11 Closeout Submittals

Drilling Logs; G, DG

The Contractor shall keep accurate drilling logs as specified in paragraph Drilling Logs

Drilling and Grouting Records; G, DG

All drilling and grouting records, including instrumented packer records, shall be as specified in Section 31 09 14 DATA MANAGEMENT

SYSTEM.

Slurry Control Drilling And Grouting Final Report; G, DG

Upon completion of the contract work, the Contractor shall submit a final report as specified in paragraph Slurry Control Drilling And Grouting Final Report.

1.6 MATERIALS DELIVERY, STORAGE, AND HANDLING

1.6.1 Grout Materials

A sufficient quantity of cement, water and ancillary grout mix components shall be stored at or near the site of the work to insure that grouting operations will not be delayed by shortage of grout materials or water.

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All materials shall be adequately protected from inclement weather, including rain, snow and freezing conditions. Suitable enclosures, to prevent the degradation of the various materials prior to use, will be required.

1.6.2 Care and Delivery of Core

The Contractor shall be solely responsible for preserving all rock core retrieved from verification drilling in good condition on site at the designated Temporary Construction Facility to await approval prior to delivery to the Permanent Storage Facility at Neville Island, unless otherwise designated by the Contracting Officer. Core shall be kept from freezing and from undue exposure to the weather, and boxes shall be kept clean and labeling shall remain legible while the core boxes are in the Contractors possession and until final acceptance and delivery.

1.7 GEOTECHNICAL SITE CONDITIONS

Refer to Volume 2 - 2012 Geotechnical Baseline Report. Drilling and grouting operations in the Critical Area shall be restricted to 1 October through 1 March in order to protect against conditions associated with the grouted void where hard grout is adjacent to soft wet soils and there is a potential for voids.

Seepage in the left abutment above El. 1630 may be of concern during grouting. Conditions discussed in the Geotechnical Baseline Report should be taken into account when planning grouting operations.

1.8 QUALIFICATIONS

1.8.1 Lead Grouting Geologist/Geotechnical Engineer Credentials

The Contractor shall provide a qualified, Professional Geologist and/or Geotechnical Engineer meeting the requirements as specified in 01 45 00.00 10 QUALITY CONTROL, experienced in drilling and grouting of dams and with all grouting equipment used on the project site. The Lead shall oversee all Automated Grouting Control and Data Collection System operators, water pressure testing, grouting, and equipment calibrations.

This individual shall be responsible for the Automated Grouting Control and Data Collection System and for the preparation of separate plots and reports for each boring water pressure test and grout stage.

The presence of a Government representative or the keeping of separate drilling records by the Contracting Officer shall not relieve the Contractor of the responsibility for the work specified in this specification.

1.8.2 Automated Grouting Control and Data Collection System Operator Credentials

The Automated Grouting Control and Data Collection System (AGCDCS) Operator shall have a minimum of 1 year of experience operating the equipment and 3 years of foundation grouting experience.

1.8.3 Drill Rig Operator Credentials

The Drilling Inspectors shall meet the qualifications identified in 02 32 00

SUBSURFACE DRILLING, SAMPLING, AND TESTING.

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1.8.4 Lead Geologist/Geotechnical Engineer Credentials

The Lead Geologist/Geotechnical Engineer shall meet the qualifications and have the same responsibilities of the lead identified in 02 32 00 SUBSURFACE DRILLING, SAMPLING, AND TESTING, except for overseeing water pressure testing, which shall be the responsibility of the Lead Grouting Geologist/Geotechnical Engineer.

1.8.5 Drilling Inspector Credentials

The Drilling Inspectors shall meet the qualifications identified in 02 32 00 SUBSURFACE DRILLING, SAMPLING, AND TESTING, except for monitoring water pressure testing, which shall be the responsibility of the AGCDCS Operator.

1.8.6 Surveyor Credentials

The Surveyor shall mee the qualifications identified in Section 01 32 23

SURVEY AND MAPPING CONTROL.

1.9 ON-SITE DAM SAFETY TRAINING

The Corps of Engineers will provide on-site Dam Safety Training, as described in Section 01 35 00.00 08 SPECIAL PROCEDURES for all Drillers, Drilling Inspectors, Grout Operators, Geologists and Geotechnical Engineers staffed in the field prior to commencement of drilling and grouting activities. Changes in personnel will require proof of training for new personnel. The Contractor shall coordinate with the Contracting Officer for Dam Safety Training Safety Course Scheduling 30 days in advance of drilling activities. The Contractor shall submit evidence of certification for all employees required to have the training prior to commencing drilling.

1.10 SEQUENCE AND SCHEDULING

1.10.1 General

The order in which the drilling and grouting work is to be accomplished shall be as outlined in the Slurry Control Drilling and Grouting Work Plan as approved by the Contracting Officer. No variations from this plan shall be made without the approval of the Contracting Officer.

1.10.1 Restrictions

A grouted standpipe shall be allowed to harden for seven (7) days before Zone 1 drilling can begin in the same hole. Zone 1 grout shall harden for three (3) days before Zone 2 drilling can begin in the same hole.

A grouted standpipe shall be allowed to harden for 24 hours before drilling a new hole within 10 feet of it. Therefore, there is no restriction for drilling soil and grouting the annulus for Primary series holes but the annulus grout must be allowed to harden 24 hours before the split spaced Secondary hole can be drilled.

Grout hole drilling in rock, pressure washing, water pressure testing, and grouting shall not be performed simultaneously on two holes within 80 feet of each other. Grout operations can be performed between 20 and 80 feet away from a hole which has been grouted and the grout has been allowed to harden for 24 hours. After the grout has hardened for a total of three (3)

SECTION 31 32 23.16 08 Page 17 days, work can be done on a hole 10 to 20 feet away. After the grout has set for a total of seven days, work can be done on holes closer than 10 feet. All distances shall be measured from the center of the grout hole at the closest points along the lengths of the holes.

Drilling and grouting in the Critical Area shall be performed only between October 1 through March 1 as described in paragraph GEOTECHNICAL SITE CONDITIONS. Work shall be discontinued in this area if directed by the Contracting Officer. The Contractor shall coordinate with the Contracting Officer at least 60 days prior to mobilization of grouting equipment to this portion of the dam. In the event that grouting in the Critical Area has to stop due to unseasonably high pool, the Contractor shall plan his work so that he can mobilize and grout in other locations in order to minimize cost impacts associated with high winter pool situations. If any part of a hole passes through the Critical Area, the hole shall be subject to the Critical Area restrictions unless otherwise approved by the Contracting Officer.

Cutoff wall construction cannot begin within a grouting section until the grouting program has met minimum acceptance criteria as stated in

31 56 10.00 08 CUTOFF WALL CONSTRUCTION.

For Spillway and lake water pumping restrictions, see Section 01 35 00.00 08

SPECIAL PROCEDURES.

1.11 WASTE MANAGEMENT

The Contractor shall comply with Section 02 42 00.00 08 DISPOSAL OF MATERIALS, Section 01 57 20.00 10 ENVIRONMENTAL PROTECTION and Section 01 57 23.00 08 TEMPORARY STORM WATER POLLUTION CONTROL for containment, treatment and disposal of waste materials.

1.12 PERMITS, CERTIFICATIONS, AND LICENSES

The Contractor shall comply with all Federal, State and local laws, regulations and ordinances relating to the performance of this work. The Contractor shall, at his own expense, procure all required permits, certifications and licenses required of him by Federal, State, and local law for the execution of this work.

PART 2 PRODUCTS

2.1 GROUTING MATERIAL

Balanced, stabilized portland cement-based grouts shall be used. The grouts shall be composed of water and cement, pozzolans, admixtures, antiwashout additive and sand, where appropriate and fillers in varying proportions. Eight grout mixes shall be proposed (including 4 base mixes, 1 mix with and 1 without an anti-washout admixture design, and 1 sand mix with and 1 sand mix without anti-washout admixture) for the grouting programs (Permanent Foundation Grouting and Slurry Control Grouting) and demonstrated by the Contractor in accordance with the requirements of these specifications, and shall be varied to meet the characteristics of each hole as determined by conditions encountered. The cement-sand mixes shall be available onsite but shall only be used in exceptional circumstances when drilling encounters significant drill fluid loss or tool drop, or as otherwise directed. The various materials to be furnished by the Contractor shall conform to the specifications listed in the paragraphs below and test results shall be included in the Material Test Reports

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Submittal. The Contractor shall assure that all grouting materials are compatible. Any material found to be incompatible shall be replaced at the Contractor's expense. Testing of the replacement material and revised grout mixes shall be at the Contractor's expense and shall be subject to approval by the Contracting Officer. The Contractor shall periodically check each grout material for quality control and compliance with contract requirements throughout production.

2.1.1 Water

Water is available for use from the East Branch Reservoir under the conditions described in the Alternate Water Supply paragraph in Section 01 35 00.00 08 SPECIAL PROCEDURES; however, the Contractor is responsible for testing the water quality to determine if it is adequate for drilling or grouting operations. The Contractor shall be solely responsible for furnishing water of suitable quantity and quality for use in the work.

Municipal water is not an available source on site. The Contractor shall be solely responsible for all pumps, supply lines, hoses, power and related equipment and materials necessary to provide water for the activities under this Contract. All water lines and pumps shall be sized appropriately to deliver sufficient quantity and quality of water for all concurrent activities on site. The cost of obtaining water and any cost for water quality testing and improvements shall be the responsibility of the Contractor and are considered incidental to drilling and grouting activities. The Contractor shall perform water testing prior to starting grouting work and quarterly thereafter, or at the direction of the Contracting Officer, to ensure that the water does not cause a deleterious effect on the grout. Testing shall be in accordance with ASTM C1602/C1602M for non-potable water sources only. Water from production operations may be treated and reused, except for grout mixing. Combined water is not permitted. Test results shall be included in the Water Testing for Water Used in Grouting Submittal.

2.1.2 Cement

Cement used in grout shall conform to the standard compositional and physical requirements of ASTM C150/C150M, Type II, and low alkali cement under Table 2 (Optional Compositional Requirements) and false set under Table 4 (Optional Physical Requirements). The use of bulk cement shall be permitted provided the Contractor employs methods of handling, transporting, and storage that are satisfactory to the Contracting Officer, otherwise only cement furnished in paper bags shall be accepted for use in the work. Stored cement shall remain clean and dry for mixing in a clearly identified silo. In the event the cement is found to contain lumps or foreign matter of a nature and in amounts which, in the opinion of the Contracting Officer, may be deleterious to the grouting operations, screening through a standard No. 16-mesh screen may be required or the cement may be rejected and shall be removed from the site. The Contractor shall be responsible for such screening, removal, and replacement at the Contractor's expense. The Contractor shall use any cement that has been stored at the site for 60 days or more before using cement of a lesser age. The Grouting Material submittal shall include the source(s) of cement, current mill tests, and an ASTM C150/C150M compliance certificate.

2.1.3 Pozzolans

Pozzolans shall be Class F flyash conforming to standard chemical and physical requirements for ASTM C618 with a maximum calcium oxide content of 10 percent. The fly ash shall also meet the Table 3 (Supplementary

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Optional Physical Requirements for drying shrinkage and uniformity). If used, fly ash shall constitute 15 to 25 percent of the total cementitious material content by weight. Sampling shall be done by the Contractor during mix design. Additional sampling and testing may be required at the direction of the Contracting Officer to insure compliance with ASTM C618.

All tests of pozzolans shall be made by the Contractor at no additional expense to the Government. Pozzolans may be furnished in paper sacks or in bulk. Materials shall be transported, handled, and stored so as to avoid damage, waste, or absorption of moisture. The Grouting Material submittal shall include the source(s) of Pozzolans and an ASTM C618 compliance certificate.

The Contractor may use silica fume in conjunction with or without fly ash as a substitution for cement. The silica fume shall conform to ASTM C1240 chemical and physical requirements and Table 3 (Optional Physical Requirements for uniformity). Silica fume shall be used in accordance with the manufacturer's recommendations and grout mix requirements.

2.1.4 Admixtures

Admixtures shall be added to the grout immediately before or during its mixing and shall consist of one or a combination of the following: water reducers, superplacticizers, fluidifiers, antiwashout additives and viscosity modifiers. Approval of admixtures shall be based on Level 1 testing in accordance with ASTM C494/C494M, ASTM C937, and COE CRD-C 661.

The materials shall be shipped, handled, and stored in such a way as to prevent deterioration, contamination, damage, or waste. Storage vats shall contain paddle type agitators and the entire admixture dispensing system shall be protected from extreme temperatures and conditions. If the admixture is subjected to freezing, it shall be rejected and replaced without cost to the Government. Alternatives may be proposed by the Contractor, contingent upon approval by the Contracting Officer based on test results and review of available literature. No time extension shall be allowed to compensate for the time required to review alternative materials.

2.1.4.1 Water Reducer

Water reducing admixtures shall conform to ASTM C494/C494M, Type A. The Grouting Material submittal shall include the source(s) of Water Reducers and an ASTM C494/C494M compliance certificate.

2.1.4.2 Superplasticizer

High range water reducing admixtures shall conform to ASTM C494/C494M, Type F. Alternatives may be proposed by the Contractor, contingent upon approval by the Contracting Officer based on test results and review of available literature. No time extension will be allowed to compensate for the time required to review alternative materials. The Grouting Material submittal shall include the source(s) of Superplasticizer and an ASTM C494/C494M compliance certificate.

2.1.4.3 Viscosity Modifier

Natural, soluble, bipolymer having a high molecular weight which enhances the stability of the suspension grouts shall be used. The viscosity modifier shall conform to ASTM C494/C494M, Type S.

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2.1.4.4 Fluidifier

Fluidifier shall be a compound possessing characteristics which will increase the flowability of the mixture, assist in dispersal of the cement grains, and neutralize the setting shrinkage of the grout. The quality of the material shall meet the requirements specified in ASTM C937.

Fluidifier shall be furnished in moisture-resistant paper sacks shipped in sealed containers and shall be handled and stored so as to avoid absorption of moisture, damage or waste. Material which has become caked due to moisture absorption will be rejected. The Grouting Material submittal shall include the source(s) of Fluidifier and an ASTM C937 compliance certificate.

2.1.4.5 Anti-Washout Admixture

Anti-washout admixtures shall be capable of minimizing the washout of paste, such that the maximum allowable washout is not exceeded when the admixtures is used at the recommended dose of the manufacturer.

Anti-washout admixture shall comply with the requirements of COE CRD-C 661, and shall be approved with Level 1 and COE CRD-C 61 testing. In addition, the admixture shall not alter the set time by more than 1hour earlier or

1.5 hours later than the control set time. The Grouting Material submittal shall include the source(s) of Anti-Washout Admixture and test results showing compliance with the COE CRD-C 661 and project requirements.

2.1.5 Bentonite

Bentonite shall be sodium (Na) cation, powdered montmorillonite. If used, the addition of bentonite shall be between 2 and 8 percent by weight of cement. A separate colloidal bentonite mixer shall be used to mix the bentonite and water to ensure fully dispersing and hydrating the bentonite before adding the bentonite to the grout mixer. The bentonite slurry shall be pre-hydrated for at least 12-hours prior to batching. The prehydrated bentonite slurry shall be mixed a minimum of 60 seconds after being placed in the mixer and before introducing other ingredients. A sufficient quantity of bentonite shall be stored at or near the site of the work to insure that grouting operations shall not be delayed by shortage of bentonite. A sufficient quantity of bentonite slurry shall be on hand prior to commencement of grouting a hole to prevent interruption of supply, and under conditions that shall not alter its properties. The bentonite shall be handled and stored so as to avoid absorption of moisture, damage, or waste. The Contractor shall use any bentonite that has been stored at the site for 60 days or more before using bentonite of a lesser age.

2.1.6 Sand

a. Sand for grout shall be natural sand. It shall be clean and consist of hard,…