Foundation Stabilization

Foundation Underpinning and Building Envelope Evaluation and Repair

Fort Ellsworth Condominium:
Alexandria, Va.

Building Usage: Five (5) Stand-alone Occupied Residential Condominium Buildings

Number of Stories: 4 stories

Construction Contract Value: $1 Million (approximate)

Type of Work: The structural work included the installation of helical piers to underpin the existing foundations, installation of mechanical connections to develop a diaphragm at each floor line and the engagement of the floor system to the walls. The exterior and interior masonry bearing walls required reconstruction or repair at numerous locations throughout the building. Subsurface and grade level drainage amendments were also developed to help manage surface water at the building’s perimeter. Concrete caisson’s were augured into the embankment behind the building to stabilize the slope upon which the building was founded.

SRG’s Role: During the course of our engagement with this property which has spanned over 14 years, SRG has been involved on several projects at the property. The most significant involved the investigation and remedial design of a foundation stabilization program to prevent collapse of a four story structure. SRG was initially retained to investigate unstable masonry walls (displaced/bulged) visible in the rear of the building. The buildings utilize masonry bearing walls with pre-cast pre-stressed hollow core floor planks and metal and wood roof trusses. The services of a Geotechnical consultant were also required to perform a subsurface assessment while SRG performed a detailed investigation of the above ground portions of the structure. The findings from these two investigations revealed that the building was unstable and the foundations were experiencing both a slope failure as well as a marine clay related shrink-swell issue. These combined issues required that the residents of the subject building be relocated to other housing while the structural repairs were undertaken.  SRG provided bidding services and served as the Engineer of Record and Special Inspector as required by the City during the various construction phases.

Parkfairfax Condominium HOA
Alexandria, VA

Building Usage: Occupied Condominium Buildings

Number of Stories: Three (3) stories

Number of Units: Varies per Building

Construction Contract Value: $150,000 to $350,000 (varies)

Type of Work: Structural stabilization including helical pier underpinning and subsurface drainage modifications. This work also involved foundation and masonry wall repairs and foundation waterproofing as well as crawl space ventilation and vapor barrier enhancements.  Subsurface drainage was also addressed as part of the remedial work.

SRG’s Role: SRG was retained initially to investigate the structural settlement and differential movement occurring at one (1) building where significant masonry wall distress was visible. A geotechnical consultant was retained to evaluate the subsurface conditions and provide recommendations for stabilization and water management. SRG developed a remedial design package for the subject building and the package was competitively bid. SRG assisted the Owner in the contract negotiation phase as well as performed the construction observation and contract administration services during the construction phase of work. SRG also served as the Structural Engineer of Record on this project.

Three (3) other buildings experienced differential foundation settlement over a period of several years that required stabilization as well. These buildings also required underpinning using helical piers and subsurface drainage systems. Masonry repairs to address various masonry issues were also included in each of these projects.

The project also included a property wide survey to identify and prioritize the buildings into three (3) categories as follows:

1. What buildings require or may in the future required foundation stabilization;
2. Which buildings require masonry façade maintenance/repair and should be surveyed periodically; and
3. Which buildings are low priority and seem to not be impacted by shrink/swell sensitive clay soils.

This survey was used as the basis for future planning and budgeting in anticipation of the need for future foundation stabilization, masonry repair and periodic maintenance work.

Woodside Square Condominium
Glen Burnie, MD

Building Usage: 38 Building Community

Number of Units:  153

Construction Contract Value: $140,000 (approximate)

Type of Work: Repair of concrete masonry unit (CMU) foundation walls at four buildings and installation of below grade waterproofing.

SRG’s Role: SRG was initially retained to perform a structural investigation of significant leaks and structural distress along a basement wall at four (4) buildings and develop a repair design package to address the repair of these conditions. This work was competitively bid and SRG assisted the owner in the contract negotiation phase. SRG also performed construction observation and contract administration services during construction process.  Subsequent to this work, SRG was retained to perform a community-wide building envelope (cladding and roof) investigation to assess the existing conditions and provide consultations regarding replacement alternatives.