Prepared by the Committee on Earth Retaining Structures of the Geo-Institute of ASCE. This Geotechnical Special Publication presents techniques and design methods for braced and tied-back excavations. Braces and tiebacks are used to provide lateral restraint in excavated areas during the construction of buildings and other civil engineering structures. The report examines in detail the essential elements of an excavation support system. Complex issues such as construction methods, support loads, base stability, ground deformation, groundwater control, and influence on adjacent property are addressed. The report outlines criteria to be considered in a good design and highlights conditions under which these criteria should be modified. Safety of the support system and the protection of facilities within and adjoining the excavation are emphasized. Topics include: investigation for design and construction control; control of surface water and groundwater; system stability and wall loading; internal support systems; tieback support systems; and system construction and performance. In addition to assisting engineers make essential safety decisions, GSP 74 provides information and conceptual orientation for owners, funding agencies, contractors, and engineering and architectural staff.