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:
City of Allen Park


Location:
Allen Park, Michigan


Prime Consultant:
Wade Trim Associates, Inc.


Total Project Budget:
$10.2 Million


NTH Project Budget:
$659,000


Start Date:
April 2008


Completion Date:
Fall 2011



NTH’s Value Added
Due to NTH’s geotechnical instrumentation program and years of experience, we were able to assist WTA in developing methods for the contractor to control ground movement while tunneling under sensitive utilities including: Norfolk Southern and Canadian National Railroad tracks, gas and multiple oil lines, EB and WB I-94, and a DWSD 54-inch diameter watermain. Critical geotechnical assistance was provided during tunneling, open cut, and temporary earth retention system construction.

Allen Park Tunnel

Upstream Storage and Conveyance Tunnel

NTH Consultants, Ltd. (NTH) provided geotechnical engineering and instrumentation investigation and design services followed by construction material testing and geotechnical instrumentation monitoring services for a proposed 96-inch inside diameter upstream storage and conveyance tunnel with pump station in Allen Park, MI. The existing system is over-whelmed during wet weather conditions causing untreated overflows into surrounding waterways and backups into residential basements. The existing sanitary system does not conform to the clean water act that the State of Michigan has required the City of Allen Park to be complaint with by 2018. To achieve compliance, a soft ground tunnel was to be constructed in close proximity to sensitive utilities and existing infrastructure.

NTH implemented an extensive geotechnical investigation including 12 testing borings and one rock core and completed Phase I and II environmental assessments. The information obtained was utilized to provide design guidelines that would be used to assist contractor related designs for temporary earth retention systems (TERS) and the tunnel. NTH designed and installed the geotechnical instrumentation monitoring plan and assisted WTA in preliminary design elements for TERS (both rigid and flexible systems) design requirements, primary and secondary tunnel liners, and construction specifications.

The NTH geotechnical monitoring program was comprised of inclinometers, tell-tales, monitoring point arrays, and deformation monitoring points. These instruments were used to monitor soil movement and utility settlement / heave from shaft, tunnel, and open-cut sewer construction activities.

The instrumentation program was vital to the success of the project since
construction activities were performed within the influence zone of a 54-inch diameter watermain and numerous fuel/oil pipelines all located adjacent to the I-94 expressway. During construction, the contractor experienced difficulties in controlling surface settlement and lateral soil displacement due to tunneling and shaft construction activities. The geotechnical instrumentation program allowed settlements to be closely monitored and timely adjustments implemented to mitigate further settlements and protect surrounding utilities and infrastructure.

As part of the construction administration team, NTH reviewed project submittals, provided construction inspection services, and performed construction material testing including laboratory testing.

NTH years of experience with soft ground tunnels and construction of TERS within soft clay proved to be an important asset to the construction of the Upstream Storage and Conveyance Tunnel. NTH provided recommendations to the contractor for ways to control settlement of existing utilities and the surface during tunneling. These recommendations were utilized by the contractor and settlement was decreased by almost 50 percent when passing directly under major underground utilities.