Attachment_14_-_Virtual_Presentation_3DEC24_0001.pdf

B.F. Sisk Safety of Dams Modifications

Pre-Bid Meeting Phase II Construction SVS, NVS, SW-165, Borrow Area Development

December 3 - 4, 2024

Presentation Outline

• Introduction – Abelardo (Carlos) Lopez, Contracting Officer

• Solicitation Summary – Carlos Lopez

• Location – Henry Garcia

• Background - Henry Garcia

• Site - Henry Garcia

• Purpose - James Olsen

• Modification Features / Components - James Olsen

• Geology – Bryan Holmes

• Schedule - Henry Garcia

• Contracting Officer’s

Virtual Site Visit Closing Remarks and Q & A – Carlos Lopez

Solicitation Summary and Site Visit Guidelines

• Solicitation: November 12, 2024 NAICS Code 237990 - Other Heavy and Civil Engineering

Construction, Unrestricted Firm Fix Price Competitive procurement.

Refer to Section L of the solicitation for the estimated notice to proceed date for development of the schedule and proposal analysis purposed only.

Refer to Section M for Quality Predominance Evaluation and

Factors and Subfactors and information on how proposals will be evaluated.

FAR 52.222-33 Notice of Requirement for Project Labor

Agreement (PLA) and FAR 52.222-34 Project Labor Agreement are applicable to this solicitation.

Upcoming amendment extending period of performance from

1,095 days to 1,350 days Contractors are required to monitor SAM.gov for any updates to dates related to the acquisition approach and timeline.

Solicitation Summary and Site Visit Guidelines

• Site Visit Guidelines No questions will be addressed during the site visit.

All questions shall be formally submitted to the Contracting

Officer and Contract Specialist as stated in Section L of the solicitation.

Government responses at the site visit are not to be construed as solicitation supplements.

An amendment will be issued by the government to address industry questions.

The attendees of this virtual site visit, in person site visit sign in sheet, this PowerPoint, and the site visit agenda will be posted as an amendment in SAM.gov.

Background

• San Luis Dam (now B.F. Sisk Dam)

• Constructed between 1963 and 1967

• Provides water for the Federal Project (CVP) and the California State Water Project (SWP)

• Provides power generation and recreational benefits

• Dam impounds San Luis Reservoir

• Provides over 2 million ac-ft of off-stream storage

• Hydraulic Height: 303 feet

• Structural Height: 382 feet

• Crest Length: 18,600 feet

• Embankment Volume: 78 million yd3

• Minimum Freeboard: 10 feet

The B.F. Sisk Dam dedication speech was given by President John F.

Kennedy during the groundbreaking ceremony for the San Luis Reservoir in California in 1962 while standing on Kennedy Hill

Existing Facility Components

• Dam (~3.5 miles long)

• Morning-glory spillway intake

• 90-foot vertical shaft

• 9.5-foot-diameter conduit through dam, founded on bedrock

• 1,000-foot-long open channel concrete chute leading to stilling basin

• Outlet Works

• Four (4) penstocks (17.5-foot-diameter) tunneled through bedrock leading from the intake towers to the Gianelli Pumping-Generating Plant

Dam

3.5 Miles Intake towers

Spillway intake

Phase II Feature Components

•North Valley Section and South Valley Section (NVS-SVS)

• Construction of a zoned stability berm

•Slopewash 165 (SW165)

• Construction of a zoned stability berm over a shear key (near dam station 165+00)

SVS

NVS

SW-165

Phase II BA’s and Basalt Hill Quarry Locations

Phase 1 Status Update

• Completed

• Spillway Extension

• Slopewash 36

• Slopewash 180

• Slopewash 145

• Contract Completion October 2024

Why SOD Modifications?

• Seismic hazard at the site is very high.

• Potential for liquefaction of granular soils at the NVS section.

• Potential strength loss in fine-grained soils within the Slopewash and SVS sections.

• Strength loss and liquefaction beneath portions of dam could result in severe deformations resulting in risk of overtopping or internal erosion.

• The downstream floodplain contains a large population of people who would be subject to flooding from a dam failure.

Phase II Modifications

• Downstream shear keys and berms to stabilize the embankment at “weak” foundation areas

• Excavation and placement of shear key material and stability berm along with toe drains at SW165.

• Constructing of a zoned stability berm at the North Valley Section and South Valley Section (NVS-SVS).

• Development of existing Borrow Areas 12 and 14.

• Development of future Borrow Areas 20 and 21.

• Future Work

• SOD Crest Raise and filter placement on the downstream face of the dam.

• Inclusion of Dam Raise and Expansion Project Crest Raise and filter components

• Site Restoration, access roads, and install final instrumentation.

Left Abutment Section

Right Abutment section

Valley Section

NVS SVS

Slopewash Section with Existing Berm North Valley Section (NVS) South Valley Section (SVS)

SOD Modifications

• Embankment sections and nomenclature

• Based primarily on Geology

NVS-SVS Aerial View

Approx. Berm Footprint

Slightly greater than 1 mile

NVS-SVS Berm Plan

• Why differentiated? Legacy of past design concepts and differing geology.

• Depth to bedrock is shallower at NVS (30 to 40ft at toe of dam).

• Depth to Rock at SVS is great (up to ~200ft)

North Valley Section

• Main features: large stability berm and blanket drain (higher than SVS).

• Blanket drain material produced on site: Zone 11 (#57) and Zone 9C

South Valley Section

• Similar to NVS but…

• Lower, wider stability berm needed to limit deformation.

• Transverse (‘finger’) drains every 200 feet.

• Material produced on site at Basalt Hill (i.e., Zone 11 and 9C).

NVS-SVS Blanket Drain and Transverse Drains

Zone 11 and 9C Materials

• Zone 9C produced during test production

• Similar to C33 sand

• Up to 10% fines

• Zone 11 (i.e., ASTM C33 No. 57 stone)

• Produced on site during Phase 1 of construction.

Test production of Zone 9C from Basalt Hill

Slopewash 165

• 2000 ft long

• Minimal excavation below existing toe.

• Weak Slopewash interrupted by existing Zone 6 rockfill.

• Completed berm includes Zone 10 shear key material (15-inch minus, produced on site).

• Also includes Zone 11 and 9C.

Slopewash 165 Toe Drains

• Includes Perforated and Non-Perforated 12-inch dia. HDPE pipe.

Left toe drain

Right toe drain Extension of original toe drains

Existing Borrow Areas

Existing Borrow Areas Borrow Area 14

Basalt Hill Quarry

A A’

Existing ground surface

Final grade after prev.

contract

Existing Borrow Areas:

Example of P-wave velocities

Borrow Area 14 final grade after Phase 1 Construction

2,000 ft/sec 3,000 ft/sec

4,000 ft/sec

Future Borrow Areas

Site Geology

• Dam constructed across 1-mile gap in the foothills

• Left/Right Abutments founded on

Panoche Formation marine sedimentary rocks

• Conglomerate

• Sandstone

• Shale (Interbedded Shale-Sandstone)

• Abutments veneered by clayey Slopewash soil

B.F. Sisk Dam - Geologic Map and Profiles (USBR, 1974)

Site Geology

• Basalt Hill Quarry

• Resistant cap of basaltic flows

• Source for all rockfill materials and

9C sand

• Borrow Area 6

• Predominantly clay to clayey sand with interbedded sand/gravel

• Source for Zone 1 and Zone 8

• Not intended for use during Phase II

• Borrow Areas 12/14

• Panoche Interbedded Shale and

Sandstone

• Source for Zone 8

• Used for Phase I

• Borrow Areas 20/21

• Completed seismic refraction profiles, awaiting data processing

• Anticipated to be similar to BAs 12/14

B.F. Sisk Dam

Basalt Hill Quarry

Borrow Area 12/14

Borrow Area 6

Borrow Area 20/21

Approximate Material Requirements

Feature Zone 1

Impervious Fill (yd3)

Zone 8, Misc. Fill

(yd3)

Zone 10, Shear Key

Rockfill (yd3)

Zone 9C, Crushed

Aggregate Filter (yd3)

Zone 11 Gravel Drain

(yd3)

Rock Blanket Slope

Protection (yd3)

SW165 4,700 700,000 38,000 15,000 16,500 60,000

NVS-SVS - 13,500,000 8,500 300,000 430,000 210,000

Total 4,700 14,200,000 46,500 315,000 445,000 270,000

• 15.0M yd3 Total

• 830K yd3 Processed rockfill and aggregates

Zone 1

Zone 8

Zone 10

Zone 9C

Rock Blanket

Zone 11

Phase II SOD Modifications

• Quarry production of granular materials at Basalt Hill.

• Production of all granular embankment materials.

• Zone 8 (Miscellaneous Material) can utilize minus 8-inch waste material from Basalt Hill.

• Developing means to move material to the site from the Quarry and Borrow Area 12, 14, 20 and 21.

• The scope of Contract-2 is to construct shear key/berm at Slopewash 165 and drainage features/berm at the NVS-SVS.

Borrow Areas 12 and 14 will be developed to provide materials for use as part of this contract along with future development of Borrow Areas 20 and 21.

Construction & Schedule Challenges

• Material processing from Basalt Hill and development and distribution at Borrow Areas.

• Environmental Compliance.

• Quarry Mining and Restoration.

• Haul Roads development/maintenance.

• Safety.

• Labor Market.

2024 2025 2026 2027 2028 2029 2030 2031 2032

Contract-2 Solicitation and Construction

Future Work

• Contract-2:

• SW-165

• NVS

• SVS

• BA’s

• Future Work

• 10-foot Crest Raise for the BF Sisk SOD Project.

• Additional 10-foot Crest Raise for BF Sisk Dam Raise and Expansion Project.

Construction Contract Sequencing

BF Sisk Phase 2 Site Visit Agenda

• Meet at Borrow Area 14 "Meeting Location" (Identified on Map) ….8:30 – 9:00am

• Assign Tour Guides, Break into Groups, Review JHA ……………… 9:00 am - 9:30am

• Site Visit, SW165, NVS, SVS, Basalt Quarry, Borrow Areas ……… 9:30am - 1:00pm

• PPE - Please wear appropriate clothing for active construction site. Access Roads are rough/rocky and cars and or lower ground clearance vehicles are not recommended.

• Sign-in Sheet will be shared on sam.gov.

Contracting Officer’s Virtual Site Visit Closing Remarks and Q & A