You only have to spend a few seconds on the website Curbed Boston (www.boston.curbed.com) to realize that the Ink Block development in the South End is one of the most talked about projects in Boston. The former Boston Herald site at the intersection of the Massachusetts Turnpike (Interstate 90) and the Southeast Expressway (Interstate 93) has been transformed into a mixed use development, including the highly successful Whole Foods Market, the Ink 1, 2 and 3 apartment buildings, and the Sepia condominiums.
Since 2007, GZA has provided a wide range of geotechnical and environmental services to National Development on this exciting project, starting with environmental due diligence and continuing through design and construction. The development included partially demolishing the 100,000-square foot former Boston Herald Building, leaving the basement and the foundations intact. New residential and retail buildings were constructed on the former foundations, with the existing basement used for parking. Three additional 8-story buildings were constructed and a fourth building is slated to break ground within the upcoming year.
Ink Block is not the first redevelopment of the Site. Prior to the beginning of filling in the 1800s, there were several wharves extending through the Site. Starting in the mid-1800s, the Site was filled, streets were constructed, and numerous brick and timber residential and commercial buildings were erected, supported by timber pilings. As part of the urban renewal wave of the 1950s, these buildings were demolished and buried within their own basements prior to the construction of the Boston Herald building. As a result of this process most of the brick, granite blocks, and timber piles remained in the fill, resulting in some unique environmental challenges during the redevelopment of the property. GZA collaborated with the owner, contractor and MassDEP to develop solutions to the issues, allowing construction to proceed. GZA provided Licensed Site Professional (LSP) services on the project from initial reporting through the preparation of Release Abatement Measure plans, and is currently preparing a Permanent Solution Statement to bring the site to regulatory closure under the Massachusetts Contingency Plan (MCP).
In addition to environmental services, GZA provided geotechnical services on the project. Subsurface conditions are typical of those underlying the portions of Boston on filled land, with fill, organic silt/peat, Boston Blue Clay and glacial till overlying bedrock at depths of between 90 and 130 feet. Though a typical profile, there were some unique challenges during the development of foundation recommendations for the new buildings. These included:
• Design criteria for the reuse of existing foundations;
• Permanent groundwater control;
• Settlement caused by proposed raises in grade;
• Seismic design parameters, given the thick organic deposits present at the Site; and
• Protection of the existing structure during construction.
GZA recommended that: 1) the existing caissons be reused to support the proposed building being constructed on the existing basement space provided that new loads were no greater than existing loads; and 2) new buildings be supported on driven piles. Pile locations adjacent to the existing building were preaugered to help protect the building from potential heave and/or vibration damage, and lightweight aggregate fill was used in some areas to reduce potential post-construction settlement.
As with all urban construction projects, soil disposal – and the potential cost and schedule impacts of off-site soil disposal – was a major concern. For this project, there was a deep (15-foot) fill required in the former loading dock area. While some site soils were reused in this area, over 38,000 tons of excess soils had to be disposed of off-site. GZA prepared soil documentation packages for several in- and out-of-state facilities to dispose of the different classifications of soils encountered at the site.
The long and varied history of the site created a correspondingly long list of environmental and geotechnical challenges during the design and construction of Ink Block, but GZA was able to attack all these challenges by putting together a strong and varied team of professionals. And now the Ink Block development is well on its way towards being at the forefront of a new revival in this corner of Boston.