El Dorado Beach Improvement Project Case Studies
Project Description: $4.8 Million LEED Project includes site rehabilitation and improvements
of the existing city park along the south shore of Lake Tahoe. Project
requirements include high standards for materials and building systems
to promote sustainable building practices. The project is expected to
become a showcase of collaboration, innovation and sustainable building
practices that will significantly improve erosion control and lake clarity.
Project features include construction of a new 2,000 sf restroom and concession
facility, landscaping, retaining walls, terraces, pedestrian walkways
and bike paths as well as improved beach access to provide a world-class
open space and civic gathering place.
Project History: An internationally known team of landscape architects and planners worked
with the local community for nearly two years to develop a conceptual
plan for the site. The plan emphasizes green building design, energy and
water conservation, public transit, water quality improvements to protect
Lake Tahoe’s famed water clarity. The project is a cooperative effort
among the City of South Lake Tahoe, El Dorado County and the California
Tahoe Conservancy.
How Was Ram Jack Involved? Through a public competitive bidding process, Ram Jack of Nevada, Inc.
was awarded a subcontract to furnish and install Helical Foundation Piles
and Retaining Wall Anchors. The large concrete retaining wall (commonly
referred to as the “Helical Wall”), was constructed to provide
a public access way from the beach level up to street level. The project
designers needed a way to support the large wall foundation and tie the
wall back due to the substantial loading criteria the wall needed to withstand.
Also, since green and sustainable building practices were a focus for
this project, the design team specified Helical Piles and Anchors be used
in lieu of other deep foundation methods and techniques. The Helical Piles
and Anchors were installed only a few feet from the Lake’s edge.
Design Loads ranged from 26 kips up to 102 kips per pile and anchor. While
the Design Loads were provided by the Project Structural Engineer, design
of the helical piles and anchors was required to be performed by Ram Jack.
Ram Jack’s Engineering Department designed a combination of pile-anchor
diameters (3-1/2” – 5-1/2”) and helix configurations
to handle the design loads plus a minimum Factor of Safety of 2. All pile-anchor
types were tested to 2 times the design load. Vertical Foundation Piles
were Compression Tested in accordance with ASTM D1143. The battered foundation
and wall anchors were Tension Tested in accordance with ASTM D3689. The
project specifications required a Pre-Production Test Program as well
as a Production Test Program to verify capacities achieved during the
Pre-Production Test Program using Torque-Correlation. The physical testing
programs confirmed the Torque-Correlation Method for determining pile-anchor
capacities for the balance of the piles and anchors installed. Ram Jack
of Nevada Inc. used a track-mounted hydraulic excavator using ProDig two-stage
12K and single-stage 30K Torque Drive Heads along with material handling
and other support equipment and tooling.
Total No. of Helical Piles and Anchors installed: 36.
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