Portland Area Super Market
Geopier GeoConcrete® Column (GCC) rigid inclusions were used to support supermarket construction
Construction Schedule
- Owner: Dirigo Center Developers
- General Contractor: Consigli Construction Co., Inc.
- Geotechnical Engineer: S.W. Cole Engineering, Inc.
- Structural Engineer: Branagan Engineering, Inc.
The project included the construction of a supermarket to serve as the anchor amenity of a 2 million-square feet mixed-use development. Helical Drilling utilized Geopier GeoConcrete® Column (GCC) rigid inclusion elements that extended through the soft/sensitive clay layer. Given the challenges with the installation of rigid inclusions in thick/sensitive clays, the project included a state-of-the-art pre-production testing program.
Soils included fill underlain by a soft, sensitive clay that extended about 70 feet below grade which was underlain by till. Due to the soft clays and the planned grade-raise-fill, the settlements of footings and slabs were estimated to be excessive, which led the design team to consider ground improvement.
Geopier GeoConcrete® Column (GCC) rigid inclusions were utilized to transfer fill, slab, and foundation loads through the fill and soft/sensitive clay layer to the dense tills below. The design utilized finite element modeling to help ensure proper support of the grade-raise fill and slab-on-grade. Over 1,300 GCC elements were installed to depths up to ~70 feet below ground surface. Production was completed ahead of schedule with two rigs/crews to expedite building pad delivery to the supermarket tenant.
