Healy (TBM Grout Plant)



Impregilo / S.A. Healy Joint Venture
Portland, Oregon, USA

12 m3 per hour


  • Conceptual Design
  • Mechanical Engineering
  • Design & Supply of Control System
  • Supply/Fabrication of all Equipment
  • Supervision of Equipment Installation
  • Commissioning and Training


  • 1000 litre Colloidal Mixer
  • 5500 litre Agitation Tank
  • Micro-Ingredient Weigh Hopper
  • PLC/MCC Control System
  • Pneumatic Control System
  • Equipment Support Skid
  • Screw Conveyors and Valves
  • All Required Piping and Valving
  • Full Batch Recording

Team Mixing Technologies supplied this automated grout plant for the Combined Sewer Overflow (CSO) Project in Portland Oregon. The project utilizes two Herrenknecht tunnel boring machines and includes construction of 4.2 miles of 14-foot diameter concrete-lined tunnel, a 220 million gallon per day pump station, 4,500 feet of parallel 30” and 48” force mains, 7,400 feet of 72” and 84” interceptor pipe, and other miscellaneous pipelines.

This TMT Tornado system produces cementitious grout used in conjunction with pre-cast concrete segments to line the tunnel as boring proceeds in two directions.

The grout plant features a 1000 litre colloidal mixer, agitation tank, progressive cavity pump, micro-ingredient scale and admixture system. An integrated MCC & PLC control system provides full automation and batch recording.

Three silos are used for cement, flyash, and bentonite feeds. Batches may be run individually or initiated automatically via agitator tank low-level setpoint. The progressive cavity pump discharges the retarded grout underground, where a secondary high-pressure pumping system takes over.

Typical of all TMT Tornado systems, this system is self-cleaning, after every batch and features the improved mark III colloidal mill seals.