Abstract: A large relocation residential building development project in Yellow River fluvial area is on the soft subsurface soils. Under the design earthquake intensity, the subsurface soils are also susceptible to be liquefiable. This paper presents the selection of the soil improvement program that could meet the structural, loading and seismic requirements and is also cost effective, simple construction and meets the construction schedule. The owner and the design consultant should pay attention on the subsurface conditions and carefully select the ground improvement method(s). The contractor should follow the design criteria and the code requirements in the implementation of the ground improvement method(s). When an unexpected condition is encountered during the construction, the effective communications among the geotechnical investigation consultant, building design consultant and the owner are critically important.

Key words: soft soils, seismic liquefiable soils, earthquake resistance, soil cement mixed columns, drilled and castinplace reinforced concrete piles