locations

Location

Kingsport, TN

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P&J Role

Prime Contractor

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Completion Date

May 2018


Project Description

In preparation for construction of a future cutoff wall, the Tennessee Valley Authority (TVA) sought to widen the crest of the earth embankment section of Boone Dam and improve its structural stability. The scope of work included the addition of rock fill berms on both the upstream and downstream slopes of the existing embankment, with the client determining the sequence of work with consideration for stability and scheduling concerns.

Project Highlights

21

Piezometers Relocated

1,500

LF of Conduit in Duct Banks

15

Standpipe Extensions

+40

Survey Monuments Built & Installed

98,700

CY of Riprap (A3 & Class B) Installed

10,500

CY of Drainage Filters

430

LF of Toe Drain with Piping & Manholes

P&J’s Contribution

P&J relocated instrumentation and placed back into service prior to berm construction and ensured the routing and construction of duct banks were properly aligned to mitigate impacts on existing features and future projects. The upstream berm and apron construction included preparation of the subgrade, removal of oversized riprap from slopes, and installation of riprap (A3 and Class B). The downstream berm construction began with the installation of a filter and toe drain. This work was performed on 3:1 slopes which limited mobility and access. The toe drain installation included pipe installation with limited trench excavations due to dam safety concerns. A retaining wall was constructed as the sand and aggregate were placed for the berm.

The project required extensive coordination with TVA, the Engineer, and the aggregate supplier.