Rock Cut-Slope Design and Construction Auxiliary Spillway ... 2/Micآ  From Hoek, E. and Bray, J.W....

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Transcript of Rock Cut-Slope Design and Construction Auxiliary Spillway ... 2/Micآ  From Hoek, E. and Bray, J.W....

  • One Corps, One Regiment, One Team

    Rock CutRock Cut--Slope Slope Design and ConstructionDesign and Construction

    Auxiliary Spillway andAuxiliary Spillway and Relocation of SR 3051 & 302 Relocation of SR 3051 & 302

    Dewey Lake, KYDewey Lake, KY

    Michael Nield Michael Nield -- GeologistGeologist

    Geohazards in Transportation in the Appalachian RegionGeohazards in Transportation in the Appalachian Region

  • One Corps, One Regiment, One Team

    Four Main Topics of DiscussionFour Main Topics of Discussion

    Auxiliary Spillway Auxiliary Spillway –– Dewey Lake, KYDewey Lake, KY

    1. Project Description1. Project Description 2. Site Geology2. Site Geology 3. Rock Cut3. Rock Cut--Slope DesignSlope Design 4. Construction Challenges4. Construction Challenges

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Project DescriptionProject Description

    DEWEY DAM

    Located in Eastern Kentucky

    Dam completed in 1949

    Rolled earth embankment dam with a tunnel type outlet works in the left abutment.

    Huntington District

    SR 302

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Project DescriptionProject Description

    Hydrologic Deficiencies at Dewey Dam

    Dam Safety Assurance Program identified deficiencies with the existing spillway during predicted floods, resulting in a high risk of dam failure with catastrophic consequences downstream.

    Correction: Raise the Dam crest (future work) Raise crest of Brandy Keg Dike (this contract) Restrict flows to the Existing Spillway (this contract) Construct 129’ wide Auxiliary Spillway (this contract) Relocate State Routes 302 and 3051 (this contract)

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Project DescriptionProject Description

    Project Features Impacted by Hydrologic Deficiencies

    Dam

    Auxiliary Spillway & St. Rt. 3051 & 302

    Brandy Keg Dike

    Existing Spillway

    Relocation of St. Rt. 302

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Project DescriptionProject DescriptionExisting Spillway

    Existing spillway was not designed to withstand predicted flows.

    Constructed horizontal restrictors, which reduced the spillway width from 60 feet to 43 feet.

    Rock excavation by mechanical (non-explosive) methods.

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Project DescriptionProject Description

    Brandy Keg Dike

    Raised Brandy Keg Dike approximately 3 feet.

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Project DescriptionProject Description

    Relocation of State Route 302

    Design Effort

    State Route 302 was relocated as a result of the construction for the Auxiliary Spillway.

    Design was performed by Fuller Mossbarger Scott & May Engineers with close cooperation by the Kentucky Department of Transportation and the Corps of Engineers.

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Project DescriptionProject DescriptionAuxiliary Spillway

    Spoil Site

    Spoil Sites

    Excavation for Auxiliary Spillway

    Dam

    • Constructed a 129-foot wide Auxiliary Spillway through bedrock.

    • Relocate State Route 3051 and a portion of State Route 302.

    • SUBJECT OF THIS PRESENTATION

  • One Corps, One Regiment, One Team

    Four Main Topics of DiscussionFour Main Topics of Discussion

    1. Project Description1. Project Description 2. Site Geology2. Site Geology 3. Rock Cut3. Rock Cut--Slope DesignSlope Design 4. Construction Challenges4. Construction Challenges

    Auxiliary Spillway Auxiliary Spillway –– Dewey Lake, KYDewey Lake, KY

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Site GeologySite GeologyExisting and Field Data

    Geologic Quadrangle Map

    Coal Mine Adits

    Auxiliary Spillway

    Joint Measurements from Outcrops

    Coal Mine Adit

    Original SR 3051

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Site GeologySite GeologyExploratory Drilling

    Boring Location Plan

    • 2 Angled Borings to Obtain Discontinuity Orientations

    Proposed Spillway Floor & Center Line

    • 2 4-inch Diameter Core Borings, Pressure Tested at Sill Location • 4 Borings for Highway Relocation

    • Total of 17 Borings (15 2-inch diameter borings)

    Small Coal Mine Adits

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Site GeologySite Geology

    Lithology

    700

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    PE N

    N SY

    LV AN

    IA N

    AG

    E BR

    EA TH

    IT T

    F O

    R M

    AT IO

    N

    Elev. 650

    850

    750

    Geologic Column

    WEATHERED SHALE AND CLAYSTONE: reddish brown to dark gray, soft, clayey, occasionally broken or weathered.

    Low percentage of core recovery (30 -90).

    Low RQD (30 – 75).

    Core Sample

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Site GeologySite Geology

    Lithology

    700

    800

    900

    PE N

    N SY

    LV AN

    IA N

    AG

    E BR

    EA TH

    IT T

    F O

    R M

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    N

    Elev. 650

    850

    750

    Geologic Column Core Sample

    SHALE with interbedded siltstone: gray to dark gray, soft to moderately hard.

    High percentage of core recovery (90– 100).

    Medium range RQD (65 – 85)

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Site GeologySite Geology

    Lithology

    700

    800

    900

    PE N

    N SY

    LV AN

    IA N

    AG

    E BR

    EA TH

    IT T

    F O

    R M

    AT IO

    N

    Elev. 650

    850

    750

    Geologic Column Core Sample

    SANDSTONE: light gray, moderately hard, fine to medium grained, micaceous.

    High percentage of core recovery (95 –100).

    Good RQD (95 - 100)

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Site GeologySite Geology

    Lithology

    700

    800

    900

    PE N

    N SY

    LV AN

    IA N

    AG

    E BR

    EA TH

    IT T

    F O

    R M

    AT IO

    N

    Elev. 650

    850

    750

    Geologic Column Core Sample

    COAL SEAMS: black, moderately hard, slightly to severely broken.

    0.8’ to 2.7’ thick.

    Core loss common.

    Poor RQD

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Site GeologySite Geology

    Geologic Cross Sections

    Geologic Cross Section Location Plan

    Proposed Spillway Floor & Center Line

    Sill Location Station 15+33

    Upstream of Sill Station 13+00Downstream of Sill

    Station 19+00

    Flow

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Site GeologySite Geology

    2+00 1+00 2+001+00CL

    700

    3+00

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    Geologic Cross Section

    Station 15+33 – Spillway Crest

    C-91-9

    C-91-7

    C-91-6 C-91-8

    C-91-5

    SOIL SHALE & SILTSTONE SANDSTONE COAL SEAM

    South/Left North/Right

    WEATHERED SH & CLS

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Site GeologySite Geology

    2+00 1+00 2+001+00CL

    700

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    900 900

    800

    700

    Station 13+00 (Upstream of Sill)

    SOIL SHALE & SILTSTONE SANDSTONE COAL SEAM

    South/Left North/Right

    C-91-4 C-91-3 C-91-2

    Geologic Cross Section

  • One Corps, One Regiment, One Team

    Auxiliary Spillway Auxiliary Spillway –– Dewey Dam, KYDewey Dam, KY Site GeologySite Geology

    2+00 1+00 2+001+00CL

    700

    800

    900 900

    800

    700

    Geologic Section - Station 19+00 (Downstream of Sill)

    SOIL SHALE & SILTSTONE SANDSTONE COAL SEAM

    South/Left North/Right

    C-91-12 C-91-11 C-91-10

    Geologic Cross Section

  • One Corps, One Regiment, One Team

    Four Main Topics of DiscussionFour Main Topics of Discussion

    1. Project Description1. Project Description 2. Site Geolog