Due to an increase in developments that are concentrated in urban areas, excavation in building construction has deepened and widened. Consequently, it has become more critical to consider the influence on neighborhood and public nuisance during construction. Underground works occupy a large part of construction costs and periods, thus being regarded as most important. This study presents planning of excavation works in building construction at an early stage. The authors have suggested the design models for planning of retaining supports: 1) The authors have suggested three logics for planning of retaining supports identified by three Zones(A, B and C) which are categorized by degrees of Depth and Area of excavation. 2) The authors have analyzed cases which belong to Zone A(small and medium-sized excavations) and Zone B(large and deep sized excavations). 3) Especially, in Zone B, the authors have testified the possibility of an appropriate planning method of retaining support by the logic introduced from statistical discriminate analysis.
