Building Construction Handbook, Eighth Edition

Deep Basement Construction ~ basements can be constructed

within a cofferdam or other temporary supported excavation (see

Basement Excavations on pages 265 to 267) up to the point when

these methods become uneconomic, unacceptable or both due to

the amount of necessary temporary support work. Deep basements

can be constructed by installing diaphragm walls within a trench

and providing permanent support with ground anchors or by using

the permanent lateral support given by the internal floor during

the excavation period (see next page). Temporary lateral support

during the excavation period can be provided by lattice beams

spanning between the diaphragm walls (see next page).

NB. vertical ground anchors installed through the lowest floor can

be used to overcome any tendency to flotation during the

construction period

Basement Construction