Earth Pressure Balance

Earth Pressure Balance Machine (EPBMs) Systems are used for direct pipe jacking, concrete segments, liner plate and ring beam and lagging tunnel installations of 102-in. OD pipe and larger on runs generally exceeding 1,000-ft. lengths in poor soil conditions. EPBMs excavate soil while balancing machine advancement and soil pressures to minimize ground settlement. Excavated soil from the EPBM cutter chamber is injected with foam and slurry to counterbalance the face pressure which is then removed through the screw conveyor and haul unit. The operator guides the EPBM and monitors targeting data, pressures, position, speed, torque and flow from a control console to pilot an accurate course and achieve maximum productivity rates. A series of back-up cars, each with a special function follow behind the EPBM. The power container distributes power to EPBM operations and foam and slurry plants provide additives which aid in soil removal. The EPBM cutter head design and power source can be configured to best meet project geological and performance requirements.

Technical Data

Earth Pressure Balance Overview

  • Most suitable for saturated and flowing materials, foam injection is used to stabilize ground
  • Drive lengths up to 1,000-lf.+
  • EPBM systems are customized for each project
  • System monitors and maintains earth pressures by balancing machine advancement and excavation rate
  • Common types of jacking pipe: RCP, concrete segments
  • Active laser guidance system
  • Auger and haul unit system soil management