Definition - What does Face Access mean?
Face access can be defined as the provision provided in the foremost part or face of the tunnel boring machine (TBM) to allow personnel overseeing the construction project to access the face. This access is typically through the cutting chamber that houses the blades.
MIcrotunnel boring machines (MTBM) may allow only limited personnel access to the face through the pipe string. Trenchless technology has made it possible to dig through difficult terrain without the need for excavation. However, for certain unforeseeable problems, tunnel face access is essential to determine the cause of the problem and prevent loss of time and damage to the tunnel boring machine (TBM).
Trenchlesspedia explains Face Access
Face access in TBMs can be very advantageous in situations that require a change in the design owing to an unpredictable situation. Face access and a compressed airlock are provided in case the TBM encounters abrasive ground or large sized boulders, groundwater and loose soil. These factors should be considered prior to the commencement of a project and necessary equipment to correct the problem should be available at the site.
Face access can help prevent damage to the cutting equipment in case of an encounter with ground conditions unsuitable for the type of cutting blade employed and can be a cause of huge economic loss to the contractor.