Case study narrative
Project narrative
The Louisville and Jefferson County Metropolitan Sewer District (MSD) is implementing the design and construction of an off-line CSO conveyance and storage system located in downtown Louisville, Kentucky. The project consists of a 33.7-million-gallon minimum capacity deep tunnel and an integrated deep pump station located at 13th Street and Rowan Street, designed to convey captured CSOs to the existing sewer system and the Ohio River Interceptor (ORI).
Key elements of the ORT Tunnel and Shafts include 14,200 linear feet of a concrete lined 20-foot diameter tunnel approximately 250 feet deep, three drop shafts along the route of the main tunnel, a working shaft, a retrieval shaft that will be converted to a baffle drop shaft, and a deep pump station shaft.
7NT personnel provided Geotechnical Drilling and Laboratory Services for the ORT design which included exploratory borings, piezometer installation, packer water pressure testing, and laboratory soil/rock testing. These services were provided for a span of eight months from March 2016 to January 2017.
The ORT project included drilling thirty-two borings for a total of 2,225 linear feet of soil and 1,991 feet of rock.
Scope of work
Technical scope
Laboratory services
- Moisture content
- Atterberg limits
- Grain size analysis
- Hydrometer analysis
- Unconfined compression - soil
- Unconfined compression - rock
- Splitting tensile strength of rock
- Slake durability
- Rock moduli in uniaxial compression
- Cerchar Abrasivity
- Punch Penetration
- SINTEF Tests
- Thin Section Analysis
Specialized experience and technical competence
- Geotechnical engineering
- Geotechnical engineering reports
- Site investigations
- Construction design oversight
- Collection and analysis of data
- Foundation systems
- Design parameters and specifications
- Manage construction and restoration activities
