SECTION_13_54_00_-_Dam_Instrumentation_R1_0003.pdf

BUREAU OF INDIAN AFFAIRS SECTION 13 54 00

OGLALA DAM SPILLWAY AND OUTLET WORKS SECTION 13 54 00

JUNE 2023 DAM INSTRUMENTATION

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SECTION 13 54 00

DAM INSTRUMENTATION

GENERAL

1.01 SCOPE OF WORK

A. This Section specifies the requirements for fabricating, furnishing, and installing the following Work items including, but not limited to:

Reservoir staff gages.

Permanent structural monitoring points on the dam crest and embankment and a survey control point on the left abutment.

Temporary settlement monitoring points on the RCC service spillway.

Pair of piezometers at each closure embankment with water level meter.

Toe drain weirs.

Protecting the existing embankment and other facilities from damage during instrument installation.

Permanently protecting the instrumentation from damage.

1.02 REFERENCES

A. American Concrete Institute (ACI)

ACI 301 Specifications for Structural Concrete

B. ASTM International (ASTM) Standards

ASTM A240 Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications

ASTM A276 Standard Specification for Stainless Steel Bars and Shapes

ASTM C150 Standard Specification for Portland Cement

ASTM C595 Standard Specification for Blended Hydraulic Cements

ASTM C778 Standard Specification for Sand

ASTM C1602 Standard Specification for Mixing Water Used in the Production of Hydraulic Cement Concrete

ASTM D1785 Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, and 120

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ASTM F480 Standard Specification for Thermoplastic Well Casing Pipe and Couplings Made in Standard Dimension Ratios (SDR), SCH 40 and SCH 80

C. Steel Structures Painting Council, (SSPC)

SSPC Volume 2 Systems and Specifications.

SSPC - PA2 Measurement of Dry Coating Thickness with Magnetic Gages.

SSPC - VIS 1 Visual Standard for Abrasive Blast Cleaned Steel.

SSPC - VIS 2 Visual Standard for Evaluating Degree of Rusting on Painted Steel Surfaces.

SSPC - SP1 Surface Preparation Specification No. 1, Solvent Cleaning

SSPC - SP2 Hand Tool Cleaning

SSPC - SP3 Power Tool Cleaning

SSPC - SP5 White Metal Blast Cleaning

SSPC - SP6 Commercial Blast Cleaning

SSPC - SP7 Brush-Off Blast Cleaning

SSPC - SP8 Pickling

SSPC - SP10 Near-White Blast Cleaning

SSPC - SP11 Power Tool Cleaning to Bare Metal

SSPC - SP12 High Pressure Water Jetting

Guide No. 3, PA Guide to Safety in Paint Applications

D. All references shall be the latest revision.

E. Where these Specifications differ from the requirements of ACI or ASTM, the more stringent requirements shall apply.

1.03 SUBMITTALS

A. Shop Drawings

At least 30 days prior to installation, submit an instrumentation plan which includes:

a. Procedures for installation and initial instrument reading for each type of instrument;

b. Sequence of installation and coordination with other work;

c. Proposed methods to protect installed instruments from damage;

d. Copies of proposed quality control forms for documenting instrument installation;

e. Schedule for instrument installation and initial instrument reading; and

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f. Instrument manufacturers’ literature including catalog cut sheets, installation directions, operations and maintenance manuals and pamphlets, and warranty information for all instruments.

B. Quality Control

Within 5 days of installing each instrument, submit Record Drawings of the as-built instrument details, and corresponding installation record sheet, to include:

a. A list of instruments installed with installation notes, performance testing notes, and initial readings for each instrument; and

b. Drawings showing surveyed locations and elevations of instruments, including the northing, easting, station, offset, and elevation of survey monuments and control points.

c. Drawings in accordance with Section 01 78 40 – Record Drawings.

1.04 SEQUENCING AND SCHEDULING

A. Coordinate instrumentation installation with dam, associated facilities, and concrete placement.

PRODUCTS

2.01 STAFF GAGE

A. Style E manufactured by Stevens Water Monitoring Systems, Incorporated, 5465 SW Western Avenue, Suite F, Beaverton, OR 97005, Telephone 503-445-8000; or equal, with the following essential characteristics:

Porcelain enameled 18 gage iron or steel.

Minimum 3-1/2 inches wide.

Markings and holes shown on drawings.

Black numbers on white background.

Graduation marks every 0.1 foot, numbers every foot and every 1 foot.

Grommet holes installed to prevent coating damage.

Provide 3x4-inch figure plates as shown on the Drawings.

2.02 STRUCTURAL MONITORING POINTS, SURVEY CONTROL POINTS, AND

TEMPORARY SETTLEMENT MONITORING POINTS

A. Standard 2-½ inch brass caps with minimum 2-inch-long shank.

B. Inscribe each brass cap with an “X” or “+”, the monitoring point number or control point number, and station at the point of survey.

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2.03 PIEZOMETERS

A. Well Screen:

Schedule 80 PVC pipe in accordance with ASTM D1785.

Slotted PVC pipe: 0.01-inch slot openings.

Inside diameter: 2-inch.

Section length: 2 feet.

B. Standpipe

Attaches to pipe coupling on the top of porous tube.

Standpipe shall have the following essential characteristics:

a. Schedule 80, PVC pipe in accordance with ASTM D1785.

b. Section lengths: 10 feet.

c. Inside diameter: 2-inch.

d. Square-threaded flush joints, 6 threads per inch in accordance with ASTM F480.

e. Furnished with an O-ring seal.

C. Transducer and Data Logger

Geokon GeoNet Datalogger 8940 Series, 4 channel.

Geokon Model 4500AL vibrating wire piezometer.

D. Piezometer sand shall be 0.35-0.45 mm silica sand (formerly #000) with a maximum D15 less than 0.5 mm.

E. Grout and Bentonite Backfill

The recommended grout is a cement bentonite mix that will provide a strength of approximately 50 psi, representative of very stiff to hard clay (i.e., SPT N-values greater than 16 blows per foot) and consists of:

a. 30 gallons water per ASTM C1602.

b. One 94-lb sack Portland cement Type I/II per ASTM C150 or Type IL per

ASTM C595.

c. 25-lb bentonite.

Bentonite manufactured by American Colloid Company, Water/Mineral Division, One North Arlington, 1500 West Shure Drive, Arlington Heights, IL 60004; or equal, having the following characteristics:

a. Montmorillonite clay purity, minimum: 90 percent.

b. Moisture content as packaged, maximum: 10 percent.

c. Dry particles passing No. 200 screen, minimum: 70 percent.

d. Dry bulk density, minimum: 55 pounds per cubic foot.

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e. Specific gravity, minimum: 2.5.

f. PH with 5 percent suspension: 9 to 10.5.

Coated Bentonite Pellets: Bentonite pellets consisting of ¼-inch coated, slow-release pellets. The bentonite pellets are coated to prevent premature hydration during installation of the tablets. Pel Plug TR-30, manufactured by PDS Company, Inc. 105 W Sharp Street, El Dorado, AR 71730; or equal, having the following characteristics:

a. Montmorillonite clay purity, minimum: 85 percent.

b. Size: 1/4-inch diameter.

c. Non-Toxic and non-polluting.

F. Protective Casings

Flush grade steel locking vault with minimum dimensions of 24 inches by 24 inches by 24 inches. Vault shall be rated for vehicular loading and have a locking hinge lid.

Manufacturer Morris Industries or approved equivalent.

2.04 TOE DRAIN WEIR BOXES

A. Weir box shall be ¼-inch thick fiberglass reinforced polymer with a box size to accommodate a 45-degree V-notch plate capable of measuring between 8 and 204 gpm.

B. V-notch Weir Plate

Fabricated stainless steel 1/8-inch-thick conforming to ASTM A240 with 16-gauge T-304 mil finish.

V-notch shall be 45 degrees.

C. Precast Concrete Mat

Refer to Section 03 40 00 – Precast Concrete

D. Weir Staff Gage

Fabricated fiberglass.

Graduated in 0.01-foot intervals and numerically labeled every 0.1 foot.

Secure directly to weir box using fasteners recommended by Manufacturer.

E. Open Channel Flow - Atlanta, Georgia, (855) 481-1118, info@openchannelflow.com, or approved equal. Manufacturer of weir boxes, weir plates, and staff gauges for weirs.

2.05 TOE DRAIN MANHOLES

A. Refer to Section 03 40 00 – Precast Concrete and Section 33 05 31 – Thermoplastic (PVC) Utility Pipe.

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2.06 BOLLARDS

A. Provide Schedule 80 galvanized steel pipe filled with concrete as shown on the Drawings to provide permanent instrumentation protection.

EXECUTION

3.01 STAFF GAGE

A. Install per manufacturer’s instruction and as shown on Project Drawings.

3.02 SURVEY MONITORING POINTS AND CONTROL POINTS

A. Drill holes in concrete to 1-inch deeper and ¼-inch diameter wider than survey marker shank and clean with pressurized air.

B. Inject Type 3 Epoxy Anchor Grout into hole.

C. Set brass cap flush with top of concrete.

D. Survey and record the point number, monument number, station number, elevation, northing and easting.

3.03 TEMPORARY SURVEY MONUMENTS

A. Temporary survey monuments will be installed on the downstream service spillway RCC steps in areas accessible to survey equipment throughout construction.

B. Survey temporary survey monuments at least twice per week during construction of the reinforced concrete sections of the service spillway. Transmit data to the BIA Representative weekly for review.

C. Do not place the final reinforced concrete placement on the overflow spillway or non-overflow sections without prior approval from the BIA Representative.

3.04 PIEZOMETERS

A. Piezometers shall be installed on the downstream slope of the left and right closure embankments after construction of the internal filter system and placement and compaction of the embankment fill to near final grades.

B. Piezometers shall be installed using hollow stem augers (HSA) or using sonic drilling techniques. Drill holes shall have a minimum diameter of 6-inches for the piezometers.

Drilling with water or air will not be allowed.

C. The piezometers at each embankment will be installed in separate boreholes located in close proximity to each other with the 2-ft long slotted PVC pipe section 1) placed at the

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embankment fill / weathered bedrock interface for the lower piezometer and 2) the upper piezometer placed a couple of feet above the top of the blanket drain.

D. Bentonite consists of bentonite tablets that are coated to prevent premature hydration during installation of the tablets. The tablets will be installed slowly to make sure they reach the bottom of the borehole. Approximately every 5 feet, a weighted tape will be used to confirm depths. If the tablets do not appear to be reaching the bottom of the borehole, the drill rods will be used to push the tablets down. The bentonite tablets will be installed through the cased hole, with the casing removed as the bentonite tablets fill up the hole.

Once the bentonite tablets are installed to the proper depth, the cased hole will be flushed with water. For bentonite seals above the water table, a minimum of 5 gallons of water will be poured into the hole to hydrate the bentonite tablets.

E. Grout shall be used to backfill the hole above the top of the bentonite seal, as shown on the Drawings.

Take precautions, as necessary, during all backfill placement operations to prevent bridging of the backfill material, and to ensure compliance with backfill depth requirements by measurement probe checks and placement volume calculations.

F. All drill holes for instrument installation will remain open within the hollow stem auger until the backfill has reached an elevation one foot above the bottom of the last auger section or as directed. At this point, removal of one section of auger shall be completed followed by the continuation of backfill placement in compliance with this requirement. At no time shall the borehole be unsupported by the hollow stem augers or other temporary casing regardless of subsurface material.

G. Install one vibrating wire piezometer inside of each 2-inch PVC riser pipe at the depth of the middle of the slotted section and connect to the data logger. Install the vibrating wire transducer by fastening the transducer and connecting wires to a ½-inch-diameter Schedule 80 PVC pipe at the correct depth and placing the pipe inside the 2-inch-diameter PVC riser pipe to the bottom of the pipe. Two vibrating wire piezometers and one datalogger are required at each embankment (total of four vibrating wire piezometers and two data loggers for the project).

H. Complete the piezometers with a flush grade steel locking vault cast in concrete around the piezometers with the steel lid flush with the final grade. Grade around the piezometer locations to drain away from the piezometers.

I. Install data logger and connecting wires in the flush grade steel locking vault. Connecting wires from the two piezometers shall go to one flush grade steel locking vault at each embankment. Locate connecting wires below grade and protect from damage.

3.05 TOE DRAIN WEIRS

A. Provide a precast concrete mat on which to mount / secure the weir box. The mat should extend a minimum of 12-inches on all sides beyond the weir box, base anchoring clips, connecting pipes / flanges, and any portion of the structure integrated into the weir box.

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B. The thickness of the mat should be a minimum of 6-inches, but as local soil conditions may vary, the final design of the slab and anchoring details are the responsibility of CONTRACTOR and must be sized so as to prevent shifting and flotation of the weir box.

C. The concrete mat must have a smooth, troweled surface to provide uniform support over the entire base structure. The mat must be level in both directions to within 1/8-inch and free from exposed aggregate and debris.

D. Level the weir box so that the weir plate is level from front-to-back and from side-to-side (using a level on the weir plate – not the top of the weir box).

E. Once the level has been verified, complete the tightening of the anchor bolts to secure the weir box to the concrete mat.

Install stainless steel weir plate to upstream side of divider wall and bottom.

Weir plate shall be installed level.

Secure the staff gage to the weir box.

Add cover with hinge.

3.06 BOLLARDS

A. Prepare and paint metal surface in accordance with the applicable SSPC specifications.

Unless otherwise shown or specified, finish-paint the bollard “Safety Yellow.”

3.07 INITIAL READINGS

A. It is the intention of the BIA Representative to begin monitoring geotechnical instruments as soon as possible following installation.

B. Perform performance testing of each installed geotechnical instrument as soon as practicable following installation.

C. Perform initial reading of each geotechnical instrument after completion of performance testing and coordinate initial reading schedule with the BIA Representative.

END OF SECTION