Ground improvement for a freeway interchange in the United States

I-29/US 275/IA92 interchange renovation project in the US state of Iowa

3 February 2015 - Projects update and handover - United States of America

The geotechnical and mechanical characteristics of soils change over time. MENARD (Soletanche Freyssinet/VINCI Construction) carried out ground improvement works for the I-29/US 275/IA92 interchange renovation project in the US state of Iowa. Menard installed 14,000 controlled modulus columns, one of many processes applied on a broad scale.

How does it work ? Controlled modulus columns transfer part of the structure load from the surface to competent underlying layers of soil. A special hollow displacement auger drills into the soil without vibrations or spoil. A slurry or mortar is then injected into the soil via the auger stem to form a column of cemented material. This type of reinforcement reduces total and differential settling. The ground improvement project also included 54.8 linear kilometres of prefabricated drains in seven different work zones.
These measures enabled ReCO (Reinforced Earth Company, also a subsidiary of Soletanche Freyssinet) to accelerate construction of the Reinforced Earth® walls on the approach to a new bridge as well as several motorway embankments.