Terracon posted a new blog post about a unique hybrid soil nail and anchored soldier pile wall excavation support system for the Tower 12 Building project in Downtown Seattle. The project involves a 60-foot deep excavation for underground parking, but the west side of the excavation was adjacent to an existing 20-story building with three levels of below-grade parking. The hybrid system involved tightly spaced soil nails in the upper portion of the excavation wall and steeply-inclined, high-capacity ground anchors (200 kip) to support the lower portion. Check out more details on this interesting project from Terracon.
The ADSC [Editor] (Association of Drilled Shaft Contractors) [/Editor] will join the FHWA as co-sponsors of a research project to develop a database of the available grout-to-ground bond stress of Hollow Core Anchors (HCAs) and to determine if correlations exist with traditional solid bar, drill and grout soil nails. The FHWA and the ADSC are interested in documenting the performance of HCAs in soil nail wall type construction and identifying methods of quality assurance so that HCAs can be specified with confidence in appropriate applications, both temporary and permanent. [Editor] Photo of hollow core nail installation underneath an existing bridge abutment, courtesy of NCS Consultants, LLC. Read on for the rest of the release. [/Editor]
In this part 2 of 2, various types of retaining walls are examined as possible alternatives in a side-hill retaining wall situation. These include conventional wall types such as CIP walls, MSE walls, gravity walls and soldier pile walls and some less conventional approaches such as lighweight concrete fill, hybrid soil-nail and geofoam wall systems, ground improvement and micropile walls.
Part 1 of this Side Hill Retaining Wall article covered the definition, significance, problems and failure modes, investigation techniques, analysis, and construction considerations of side hill walls. A PDF version is now available for download as well. Click through for the article and the download link!