Project Description

Deep Rock Tunnel Connect

Current 7NT personnel have been involved on the Deep Rock Tunnel Connect project since 2007. Our drill crews, engineers, and laboratory personnel have been responsible for performing the geotechnical subsurface investigation and laboratory services (soil and rock) for the Design Phase of this project. Our construction inspectors have continued to provide inspection services into the construction phase of this project.

Indianapolis, IN

7NT inspectors currently supplement the construction inspection team for the project. Full time roles on the site for the 4‐5 year duration of the project include tunnel inspectors who work shifts in the 250 to 285‐foot deep tunnel documenting all activities of the Tunnel Boring Machine (TBM), including mining, re‐gripping, probe hole drilling, pre‐excavation grouting, installing rock supports, maintenance, and all of the other activities. Additional roles include the surficial inspection of the drilled launch, access/utility, and retrieval shafts of the levee extension and the spoil hauling. Our personnel also supplement the construction inspection team with a full time administrative role who maintains document control of the project record through Contract Manager software (schedule, progress, reporting).

Compliance with Performance Schedules

7NT is also responsible for all of the construction material testing on the project. This has included in‐depth testing of the levee extension for all material used to verify conformance with project specifications for type and compaction to aid in the certification of the levee prior to mobilization of the TBM down the launch shaft. This particular task was very crucial in the early stages of the project as the quantity of usable on site material was much less than originally expected. The project was facing significant issues in terms of delay and cost increase. 7NT helped to determine suitable usage for the on‐site material in different components of the levee through the application of a rigorous testing schedule. This allowed more permeable material to be used as fill in the central part of the levee while the more appropriate and impermeable material sufficiently capped the levee system]. Our team also includes a Quality Assurance (QA) Manager who is responsible for overseeing all aspects of QA for the project, but most specifically the conformance of the construction materials used to project specifications. Additional QA services include submittal & RFI review and commenting and scoping development of inspection and materials testing related activities.

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

Project Details


2007 – Ongoing




Cost Control

7NT maintains a rigorous cost control system for this project. With a firm budget established, cost control is crucial to the overall success of the project. 7NT maintains a monthly log of all project allocated costs and projects them against the project budget forecast. On a multi‐year project, any budget overages can accumulate to large sums over time. 7NT regularly works with the Client and Owner to continually adjust the level of service to meet both the needs and requirements of the project as well as to address any project related issues as they arise. An example would be the aforementioned levee testing program. A very rigorous and detailed testing schedule of all on site material as well as proposed off site borrow locations was enacted to accurately determine the amount of usable material for the levee construction as well as to further establish the appropriate usage of the material throughout the project as to reduce the cost and/or schedule increases to the project. As part of the increased testing program, 7NT staff found other areas to reduce the level of service and save cost in order to create a net‐zero impact to the project budget while still maintaining the highest level of service for the project.

Quality of Work

Being an integral part of such a large project for 5‐10 years speaks to the level of quality that our staff members have been known to regularly deliver on projects.

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