W912QR24R0048_FIO_Vol6_ProjGIR_12of16_E-0000.pdf

Solicitation For Rough River Dam Safety Modification Project Phase II - New Outlet Works and Cutoff Wall

P2: 145870

Design-Bid-Build

Geotechnical Information Report (GIR) (12 of 16) Appendix E

For Information Only

23 September 2024

W912QR24R0048

ARIMS: 1200

Disposition: Permanent

W912QR24R0048_FIO_Vol6_ProjGIR_12of16_E-0000

Rough River Dam Geotechnical Data Report for Tunnel Construction

Volume 6: Project GIR

Appendix E - Analysis of Upstream Filter and Dewatering (12 of 16)

ROUGH RIVER, FALLS OF ROUGH, KY

LOUISVILLE DISTRICT, LRD DIVISION

DRAFT

ROUGH RIVER, FALLS OF ROUGH, KY

LOUISVILLE DISTRICT, LRD DIVISION

Appendix A

SYNOPSIS OF CONSTRUCTION HISTORY AND PERFORMANCE

Appendix B

BORING LOCATION PLANS AND BORING LOGS

Appendix C

SOIL AND ROCK TESTING AND ANALYSES BY INVESTIGATION

Appendix D

INSTRUMENTATION AND MONITORING

Appendix E

ANALYSES OF THE UPSTREAM FILTER AND

DEWATERING

Appendix F

ANALYSES OF THE DOWNSTREAM COFFERDAM AND DEWATERING

Appendix G

ANALYSES OF DOWNSTREAM FILTER FOR STILLING BASIN ABANDONMENT

Appendix H

ANALYSES OF CUTOFF WALL WORK PLATFORM

Appendix I

ANALYSES OF UPLAND DISPOSAL AREA AND ARCHERY BERM

Filter Compatibility

E-1

Project:

Study Type: District: LRL

Calculation Title:

Total Number of Pages (including cover sheet): 5

Prepared by: Office: LRL Date: 10/26/2020

Checked by: Office: LRL Date: 2/4/2021

Description and Purpose

Assumptions for Critical Input Parameters

Remarks, Conclusions, and Results

Revision History Rev. No. Date

Meets particle retention and satifies the 'no erosion' design criterion; therefore, these two materials are filter compatible.

Description of Revision Approved by

Check the compatability between the Clay Fill of the embankment (Base) to the proposed KYTC Concrete Sand filter

Filter Material Used - based on KYTC specification range for Concrete Sand

Base Material Used - Upper Bound = Fat Clay with Sand (Upstream Left Abutment) See Log ADC-1909 - LL=50

- Lower Bound = Clayey Sand (Upstream Left Abutment) See Log ADC-1911 - LL=34

- adjusted lower end of curve to extend range and extrapolate a D15 value -

Steven Shifflett

Rough River Dam Safety Modification (Phase II) Project

Filter Compatability Check - (Upstream Cofferdam)

Joe Carnall

Calculation Cover Sheet Version 20181017 Page 1 of 7E-2

Prepared by: Office: LRL Date: 10/26/2020 Checked by: Office: LRL Date: 2/4/2021 Calculation Title:

Particle-Size Analysis of Filter Material Unified Soil Classification System (ASTM D2487)

Sieve Hydrometer Coarse Fine 3/8-in 9.5 100.0 100.0 No. 4 4.75 90.0 100.0 No. 16 1.18 45.0 85.0 No. 50 0.3 5.0 25.0 No. 100 0.15 0.0 8.0

Coarse Fine Average

10.0 0.0 5.0

0.0 0.0 0.0

10.0 0.0 5.0

28.0 9.3 18.6

46.9 50.4 48.6

J. Carnall S. Shifflett

Fine Gravel (%): ¾-in (19-mm) to 4.75-mm Sand (%): 4.75 mm to 0.075 mm

Particle-Size Analysis

Sieve Size

F (percent)

Gravel (%): 3-in (75 mm) to 4.75-mm Coarse Gravel (%): 3-in (75-mm) to ¾-in (19-mm)

Filter Compatability Check (Clay Base)

D (mm)

Coarse Sand (%): 4.75-mm to 2.00-mm Medium Sand (%): 2.00-mm to 0.425-mm Fine Sand (%): 0.425-mm to 0.075-mm Fines Content (%): Smaller than 0.075-mm Silt (%): 0.075-mm to 0.005-mm Clay (%): Smaller than 0.005-mm

Gradation of Filter Material Version 20200511 Page 2 of 7

E-3

Calculation Title:

Particle-Size Analysis of Base Material Unified Soil Classification System (ASTM D2487)

Step 1: Assess the gradation band of the base soil

Sieve Hydrometer Coarse Fine 1½-in 37.5 100.0 100.0 3/4-in 19 99.3 100.0 3/8-in 9.5 95.8 97.9 No. 4 4.75 92.3 94.0

No. 10 2 81.0 85.7 No. 40 0.425 78.1 83.7 No. 200 0.075 47.7 75.8

Hydrometer - 0.02 42.6 58.9 Hydrometer - 0.005 29.2 41.4 Hydrometer - 0.002 25.4 34.2 Hydrometer - 0.001 23.2 30.4 Hydrometer - 0.0001 15.0 20.0

Coarse Fine Average

7.7 6.0 6.9

0.7 0.0 0.4

7.0 6.0 6.5

44.6 18.2 31.4

11.3 8.3 9.8

2.9 2.0 2.5

30.4 7.9 19.2

47.7 75.8 61.8

18.5 34.4 26.5

29.2 41.4 35.3

Coarse Gravel (%): 3-in (75-mm) to ¾-in (19-mm) Fine Gravel (%): ¾-in (19-mm) to 4.75-mm Sand (%): 4.75 mm to 0.075 mm

Filter Compatability Check (Clay Base)

F (percent)

Gravel (%): 3-in (75 mm) to 4.75-mm

J. Carnall S. Shiflfett

Medium Sand (%): 2.00-mm to 0.425-mm Fine Sand (%): 0.425-mm to 0.075-mm Fines Content (%): Smaller than 0.075-mm

Particle-Size Analysis

D (mm)

Coarse Sand (%): 4.75-mm to 2.00-mm

Silt (%): 0.075-mm to 0.005-mm Clay (%): Smaller than 0.005-mm

Sieve Size

Gradation of Base Material Version 20200511 Page 3 of 7

E-4

Step 2: Re-grade the base soil to 100 percent passing the No. 4 sieve, if necessary

Sieve Hydrometer Coarse Fine 1½-in 37.5 - 100.0 100.0 3/4-in 19 - 100.0 100.0 3/8-in 9.5 - 100.0 100.0 No. 4 4.75 - 100.0 100.0 No. 10 2 - 87.8 91.2 No. 40 0.425 - 84.6 89.0 No. 200 0.075 - 51.7 80.6

Hydrometer - 0.02 46.2 62.7 Hydrometer - 0.005 31.6 44.0 Hydrometer - 0.002 27.5 36.4 Hydrometer - 0.001 25.1 32.3 Hydrometer - 0.0001 16.3 21.3

Coarse Fine Average

48.3 19.4 33.8

12.2 8.8 10.5

3.1 2.1 2.6

32.9 8.4 20.7

51.7 80.6 66.2

20.0 36.6 28.3

31.6 44.0 37.8

D (mm)

Silt (%): 0.075-mm to 0.005-mm Fines Content (%): Smaller than 0.075-mm

Particle-Size Analysis

Sieve Size

F (percent)

Sand (%): 4.75 mm to 0.075 mm

Clay (%): Smaller than 0.005-mm

Coarse Sand (%): 4.75-mm to 2.00-mm Medium Sand (%): 2.00-mm to 0.425-mm Fine Sand (%): 0.425-mm to 0.075-mm

Gradation of Base Material Version 20200511 Page 4 of 7

E-5

Calculation Title:

Filter Design Criteria Particle Retention (No Erosion Condition) (FEMA 2011)

Step 1: Assess the regraded base soil category for the finest base soil

FC (fine band) 80.6 percent (after regrading)

Base Soil Category 2 Dispersive base soils? No

Step 2: Assess the gradation of the coarsest filter material

D15F (coarse band) 0.422 mm

D85B (fine band) 0.185 mm (after regrading)

D15F ≤ Maximum D15F (from above table) 0.700 mm Meets

Filter material satisfies the 'no erosion' design criterion.

Potential failure mode may be excluded from further consideration since internal erosion will not continue.

Fines Content (percent)

Base Soil Category

Particle Retention

J. Carnall S. Shifflett

≤ 6.5(D85B) but not less than 0.2 mm ≤ 0.7 mm ≤ 0.5 mm

Base Soil Description

FC > 85

40 < FC ≤ 85

15 < FC ≤ 40

Fine silt and clays Sands, silts, clays, and silty and clayey sands

Silty and clayey sands and gravels

Base Soil Category

4 ≤ 4(D85B) ≤ 4(D85B)

FC ≤ 15 Sands and gravels

Non-Dispersive Soils Dispersive Soils Maximum D15F

≤ 9(D85B) but not less than 0.2 mm

≤ (4(D85B) – 0.7)�

40 – FC

25 � + 0.7 ≤ (4(D85B) – 0.5)�

40 – FC

25 � + 0.5

Filter Design Criterion for Particle Retention Version 20200511 Page 5 of 7

E-6

12-in 3-in 3/4-in #4 #10 #40 #200

CE EE SE NE

CE EE SE NE

0.11101001000

Pe rc en t F in er b y w ei gh t

Particle Size (mm)

U.S. Standard Sieve Numbers

Hyd

E-7

Calculation Title:

Filter Design Criteria Permeability (EM 1110-2-1901, Change 2, 28 Jan 2005)

Step 1: Assess the D15B of the finest base soil before regrading

D15B (coarse band) 0.000 mm (before regrading)

Step 2: Assess the D15F of the finest filter material

D15F (fine band) 0.200 mm

D15F ≥ (3 to 5)(D15B), but not less than 0.1 mm Note: Reclamation (2011) requires D15F ≥ 5(D15B), but not less than 0.1 mm Note: NRCS (2017) requires D15F ≥ (4 to 5)(D15B), but not less than 0.1 mm

D15F ≥ 3(D15B), but not less than 0.1 mm 0.000 mm Meets D15F ≥ 4(D15B), but not less than 0.1 mm 0.000 mm Meets D15F ≥ 5(D15B), but not less than 0.1 mm 0.001 mm ◄ USBR/NRCS Meets

Filter material is sufficiently permeable to perform the required drainge function.

J. Carnall S. Shifflett

Filter Compatability Check (Clay Base)

Filter Design Criterion for Permeability Version 20200511 Page 7 of 7

E-8

Excavation Dewatering

E-9

CONTROL TOWER EXCAVATION DEWATERING

Maintenance dewatering The grout curtain surrounding the control tower excavation will be the primary method for keeping water out of the pit; however, this will not stop all the seepage, so a system is required to collect and expel the seepage that does gets through. Collection tanks/pits will be placed near each end of the cofferdam and will receive water pumped up from the bottom of the excavation as well as any through-embankment seepage directed to them. The collected water will then be pumped outside of the cofferdam. The maximum rate of seepage into the excavation was estimated at 1,200 gallons per day (including a safety factor of 2); however, the karstic nature of the rock and unknown effectiveness of the proposed grouting makes this difficult to determine and the system will need to be adaptable to the evolving condition of a fluctuating pool and precipitation. The specifications will include performance-based requirements to maintain a dry working environment suitable for construction activities for which the contractor will be responsible for designing.

Dewatering of flooded excavation Until the tunnel is complete and ready for use, pumps will be required for all water removal. It will be important to quickly remove the water should the control tower excavation flood;

therefore, high-volume pumps will be required based on the estimated maximum potential volume of 950,000 cubic feet (7.1 million gallons) of water. The maximum depth of flooding would be approximately 90 feet. According to manufacturer pump curves, twelve-inch centrifugal pumps are capable of pumping between 1,500 and 4,000 gallons per minute within the recommended operating range. The actual flowrate achieved is dependent on the operating conditions of the pump (head, RPM, turbidity, etc.). At a head of 80 feet, a 127.5 HP pump operating at 1100 RPM can pump 3,000 gpm. At this pump rate, a single pump could dewater the excavation in 40 hours. However, pump curves are based on clear water while the water in a flooded excavation would have a significant amount of sediment and debris, so it is likely that lower flowrates would be achieved in the field. It is also anticipated that flow/seepage into the excavation would continue during pumping which would further increase the pumping time.

An additional concern for dewatering a flooded tower excavation is the available suction head of centrifugal pumps. 12-inch centrifugal pumps are capable of handling heads in excess of 100 feet, but this is on the discharge side. In this instance, the water would be pulled up to the pump, which makes suction lift (or Net Positive Suction Head, NPSH) the limiting factor for design.

The NPSH ‘required’ (NPSHR) is provided on the pump curve. For a centrifugal pump at 3000 gpm, the NPSHR is 12 to 13 feet. NPSH ‘Available’ (NPSHA) is calculated using the following equation:

E-10

NPSHA h h h h h

Where:

hatm = atmospheric head hvapor = vapor head hf(total) = total head lost to friction hlift = lift head hv = velocity head

For the pump to work without cavitation, the NPSHA must be greater than NPSHR. By estimating the atmospheric head, vapor head (negligible), friction loss head, and velocity head, the maximum allowable lift head was calculated at approximately 17 feet. This means that without modifications, the pumps would only be able to pump water that was 17 feet or less below their elevation. Since the control tower excavation is over 80 feet deep, the centrifugal pump alone is not adequate to dewater a completely flooded excavation.

One method to overcome the suction lift limitations is to move the pumps to a lower elevation as the excavation is dewatered. However, this is impractical as multiple pump moves would be required to dewater the entire depth and work within the pump’s suction lift capabilities. These pump moves would extend the dewatering time. Additionally, the plans for the excavation do not show enough benches for this process to be possible.

The recommended alternative is to use submersible and centrifugal pumps together. The submersible pump pushes the water up to a level where the centrifugal pump can assist with suction, and then discharge it. The submersible pumps rely on input flow of up to 90 gpm which can be provided by the existing centrifugal pump power source. The combined centrifugal/submersible pump system has been used successfully on offshore oil platforms for fire suppression systems where a water must be pumped up a large distance (high suction head) at a high flow rate (Figure 1), and is the recommended means to dewater a flooded control tower excavation. For flexibility in the contract, the contractor will be responsible for selection of the exact equipment used. The specifications will include performance guidelines that must be met.

E-11

Figure 1: Combined centrifugal/ submersible pump system

E-12