Owner: University of Southern Maine Partner: PC Construction Type: Ground Improvement, Rock Anchors Location: Portland, Maine Project Description: For this project, HB Fleming installed 24 rock anchors with a design load of 206 kips in tension, 378 rigid inclusions with a design load of 106 kips in compression, 106 stone columns with a design load…Details
When soil and loading conditions are right, ground improvement can be a cheaper and faster alternative to deep foundations (pile). H.B. Fleming typically uses vibro stone columns (VSCs) or rigid inclusions to increase the bearing capacity of in situ soils and limit settlement to acceptable levels.
The basis for whether VSCs or rigid inclusions are an appropriate solution is governed by subgrade soil conditions and by specific loading conditions. Some soil profiles and loading conditions lend themselves to VSCs. In some cases, grouted VSCs are required. In particularly weak soils, rigid inclusions may be needed.
One of the advantages of these types of ground improvement is their ability to provide a defined, improved soil-bearing capacity at working grade, so foundations can be constructed using the same methods as conventional shallow foundations. Another advantage of VSCs and rigid inclusions over other types of ground improvement is that no spoils are generated. This is an important consideration in situations where contaminated soils may be present.