Despite advances in construction shoring
techniques, engineers and shoring contractors today still face many of the same
challenges early builders faced. The design and construction of shoring systems
can be complex due to the soil structure, depth of cut and ground water,
weather conditions, superimposed loads, seismic loads, vibrations, and adjacent
construction. Excavations in wet soil, sandy soil, or areas that have been
backfilled can be unstable and require properly designed and constructed excavation
shoring systems. Even hard rock can be hazardous to excavate. A shoring
contractor may need to guard against an unstable excavation bottom, especially
when below the water table.
Support of Excavation
Buildings, construction equipment, and
stockpiled materials including soils located adjacent to an excavation result
in lateral loads on construction shoring. Not permitting heavy loads to be
located within the zone of influence of the shoring wall reduces or eliminates
this loading. Underpinning of adjacent structures can reduce the loading on an
excavation wall and reduce the risk of the building settling. Excavation
shoring can be affected by vibrations from such sources as traffic, railways,
blasting, and machines operated in adjacent buildings.
Common permanent and temporary shoring
systems include steel sheet piling, soldier piles and lagging, jet or chemical
grouting, secant or tangent piles and soil nail walls. Anchors or bracing can
be used to provide lateral support of sheeting and shoring systems. Access
shafts for tunneling and trenchless construction may involve a circular shoring
system designed as a compression ring to resist loading. Support of excavation during construction shoring which is open for extended periods of time may require protections
from weather conditions.
Extreme caution must be used during any shoring
excavation and safety is of utmost importance. Hayward Baker Inc. understands
the hazards associated with earth shoring and the importance of trench safety.
Hayward Baker is the shoring company with experience and the full range of
techniques to provide reliable earth shoring and retention.