Construction is Under Way!
June 4-9, 2008
The exhilarating South Waterfront District as viewed from the Portland Aerial Tram. The Mirabella construction site is visible at the lower center of the photograph.
Mirabella at South Waterfront under construction is visible to the left (east) of the grassy future South Waterfront Neighborhood Park in the above photograph. Now into the seventh week of construction on site, work continues to progress at a positive pace.
A bird’s-eye view of the Mirabella construction site from the northwest shows several ongoing activities, including: placement of sheet pilings (upper middle and right in photo); placement of some of the final shoring piles near the southwest corner of the site (see tall yellow drill rig at upper right in photo); lagging wall along the western, northern, and eastern edges of the site; and placement of tie-backs at the northern shoring wall (see partially-visible yellow auger in the excavated cavity, at far left in photo). Mass excavation (removal of remaining excess soils from the site) began during the second week of June and will continue through the month.
The above view along the southern edge of the Mirabella site shows the placement of the final sheet piling near the southwest corner. Visible above are the I-beam shoring piles (extending approximately 60-feet vertically into the ground) and the corrugated steel paneled sheet piles, which will define the southern edge of Mirabella’s basement valet parking garage.
Above is a view northward of a shoring wall tie-back being augered into place along the western (Bond Avenue) edge of the construction site. During the tie-back placement process, a hollow tube casing is placed laterally outward, then hand-loaded with steel cables (tendons), which are tension loaded following the placement of high strength grout into the augered shaft. The tie-backs provide lateral reinforcement to the vertical basement walls.
The above view also shows the traditional lagging wall shoring system, which is being used on the western, northern, and eastern edges of the Mirabella site. The interior faces of the wood board lagging walls will eventually receive a shotcrete (concrete that is sprayed on with a hose, then trowel-finished) finish.
