NTH Consultants
Contact Us
  • Home
  • Markets
    • Energy Market
    • Industry Market
    • Water Market
    • Transportation
    • Community Development
  • Services
    • Geotechnical Engineering >
      • Geophysical Services
      • Mapping
      • Shoreline Services
      • Civil Site Engineering and Design
      • Construction Materials & Geotechnical Testing Services
      • Electric Substation Services
      • Geotechnical Engineering for Transportation Facilities
      • Underground Engineering Services
      • Subsurface Utility
      • Signature Projects
    • Environmental Services >
      • PFAS
      • Ecological Services
      • Environmental Health Services
      • Environmental Remediation Services
      • Environmental Compliance
      • Environmental Permitting
      • Environmental Site Assessments
      • Ecological Services for the Energy Market
      • Air Quality Permitting and Compliance
      • Brownfield Site Redevelopment
      • Environmental, Health & Safety Training for Employee Development
      • Hydrogeologic Studies
      • Landfill Related Services
      • Site Acquisition and Redevelopment
      • Storage Tank Services
      • Signature Projects
    • Facilities Engineering >
      • Decommissioning
      • Structural Condition Assessment Rehab
      • Bridge Engineering Services
      • Asset Management Services
      • Concrete Restoration
      • GIS Services
      • Masonry Evaluation Services
      • Pavement Engineering and Consulting
      • Roofing Technology Services
      • Structural Condition Assessment
      • Signature Projects
  • Projects
  • About Us
    • Mission + Core Values
    • Leadership
    • News and Events
    • Employee Portal
  • Webinars
    • Emergency Actions Plans Webinar
  • Careers
    • Why Join NTH
    • Who We Are
    • Career Opportunities
    • NTH Internship Program
  • Blog
  • Contact Us
Back to Signature Projects
Picture
Client: 
Oakland-Macomb
Interceptor Drain Drainage District


Location: 

Oakland and Macomb
Counties, Michigan


Start Date: 

Jan. 2012

Completion Date: 

Feb. 2013

Oakland-Macomb Interceptor Tunnel

Finite Element Determination of Sewer Stresses

NTH Consultants, Ltd. performed finite element design services for the analysis of a distressed sewer, located at a depth of 60’ below the ground surface. The concrete sewer walls had eroded, and an analysis was performed to see if the loss of wall would place the sewer in danger of collapse. NTH performed a soil investigation of the area, and took cores of the concrete walls and tested them to determine concrete strength and actual wall thickness. This information, combined with the known inner diameter of the sewer, allowed us to prepare a finite element model of the sewer wall, based on actual conditions.

The sewer ran several miles, and 11 locations were analyzed. The sewers were originally constructed as an ellipse, with differing inner and outer diameters. As a result, the wall thicknesses and diameters changed for each location. An excel spreadsheet was developed so that the input text for nodes and plates would be provided as a direct output in an excel generated report. This output could be directly copied into the STAAD Pro editor so that plates and nodes would be auto-generated.

A comprehensive finite element analysis was performed for each of the 11 locations. It was determined that only one of the locations was in imminent danger.