Updates from GNCB
By GNCB 18 Aug, 2017

GNCB believes that it is important to foster students’ interest in the fields of structural engineering, geotechnical engineering, and historic preservation. The firm is proud of its internship program which supports students at both the high school and college levels. This summer, Ms. Eleanor Phetteplace of Roger Williams University (RWU) joined GNCB as an intern. Ms. Phetteplace is an Engineering major, with a specialization in civil engineering, and is minoring in both Historic Preservation and in Mathematics. She began her internship in May ( GNCB Welcomes Eleanor Phetteplace ).

While working at GNCB, Ms. Phetteplace was given the opportunity to work with our engineers is all three departments. She was tasked with a wide range of assignments both in and out of the office. As her education and interests lean towards historic preservation, Ms. Phetteplace worked mostly on existing and historic structures where she was responsible for site surveys, condition assessments, structural calculations, writing reports, and drafting. Some of her historic projects included unreinforced masonry mill buildings, timber churches, a caisson foundation lighthouse and several academic buildings.

In addition to working with existing buildings, Ms. Phetteplace worked on new construction projects where she helped create 3D Revit models and determined dead and live loads on bearing walls for the design of spread footings. Additionally, she conducted research on Fall Protection standards in order to participate in the assessment of fall protection systems for a Massachusetts college.

With our geotechnical engineering department, Ms. Phetteplace participated in the soil investigation of a new hotel site in central Massachusetts. As she has not yet taken any soils-related classes, she found this assignment particularly interesting and looks forward to incorporating geotechnical courses into her curriculum as her education continues.

Ms. Phetteplace’s favorite aspects of this internship included gaining knowledge and experience with structures in the field during site surveys and construction administration. She believes that her new skills with Autodesk Revit and Risa-3D will be incredibly beneficial in her future as a structural engineer. She also enjoyed learning about the interaction between design team and construction team members at different project stages.

By GNCB 08 Aug, 2017

The Church of St. Michael the Archangel reached its next milestone this July with the installation of its new steeple. The steeple is a reconstruction of the original steeple based on archival photos of the civil-war era Church. The original steeple blew off the Church shortly after it was built, making its reconstruction an integral component of this Project.

The steeple is anchored to the structure with a series of bolts fastened through the octagonal base of the steeple and an octagonal angle frame designed by GNCB. The steeple is braced with chevron braces within its square base which is constructed with structural steel designed to accommodate the replicated tapering of the original steeple.

Phase 1 of the reconstruction of St. Michael Church will soon be completed. In addition to the installation of the steeple, the cold-formed steel shear walls are close to completion as the exterior cladding and stained glass windows are being installed. The east and west entrances and rear additions are in progress. Phase 2 of the project will include the interior fit-out and finishing of the Church.

This marks the second major milestone in the reconstruction of St. Michael. The first milestone, the raising of the first timber truss , was celebrated by the Parish with a truss-raising ceremony during which Bishop Michael Cote of the Diocese of Norwich blessed the first truss before its installation.

Architect: Geddis Architects

Construction Manager: Petra Construction

Steeple Fabricator: Campbellsville Industries, Inc.

Watch the videos of the steeple and cross installation.

Steeple Installation Video

Cross Installation Video

By GNCB 07 Aug, 2017

GNCB recently provided geotechnical engineering and construction administration services for the recent renovation to Putnam High School located off of Woodstock Avenue in Putnam, CT. The project included classroom and library renovations and the addition of an expanded gym along the southeast side of the 1950s building. Other site improvements included expanding the parking areas, redirecting traffic and bus flow, and constructing retaining walls. The $36.6 million project was led by O&G Industries, of Torrington, CT, as construction manager.

GNCB’s services included a test boring program which revealed site conditions that consisted of thick sand and gravel. Previous site utility work resulted in deposits of man-placed fill at some areas. The man-placed fill required removal and replacement with compacted structural fill. The full extent of the fill was uncovered during construction, during GNCB’s field monitoring of building footing preparation. The deep cuts at the south end of the site for the new parking area enabled the on-site reuse of the excavated sand and gravel as structural fill.

Architect: Drummey Rosane Anderson (DRA Architets)

Construction Manager: O&G Industries

By GNCB 24 Jul, 2017

The Connecticut Cancer Foundation Headquarters in Old Saybrook, CT is close to completion. The Headquarters is GNCB’s latest “hometown” project. Throughout our 52 years in Old Saybrook, our structural engineers, geotechnical engineers, and historic preservationists have been involved in numerous Town projects including the elementary, middle, and high schools, the Katharine Hepburn Cultural Arts Center, the stabilization of the Town Dock, and various residential projects.

The CT Cancer Foundation Headquarters consists of a 4,400 square foot addition to the Sanford House, an early 19th-century, timber-framed home. The addition consists of reinforced concrete foundations supporting a steel-framed first floor and a wood-framed superstructure.

GNCB designed a strong-back system for the perimeter of the Sanford House to allow removal of the first floor framing and increased headroom for the new Headquarters. The original House’s chimney was removed at the interior of the building and is supported and stabilized with a new engineered wood framing system.

GNCB served as Structural Engineer of Record for the Headquarters. Additionally, our firm provided historic preservation and special inspection services for this project.

Architect: Point One Architects

Construction Manager: Enterprise Builders, Inc

By GNCB 17 Jul, 2017

The reconstruction of the second floor balcony around the perimeter of 30 Derby Avenue in Orange, CT was recently completed. 30 Derby Avenue, also known as the Henry F. Miller House, is an example of international style architecture and is on the National Register of Historic Places. The second floor balcony, which was severely deteriorated due to water infiltration, exemplifies three characteristics of international style architecture including the integration of structure and site, taking advantage of the climate, and providing simple aesthetic features. GNCB provided a condition assessment, construction documents, and construction administration for this project which reestablished the balcony structure and perimeter railing.

The damaged double-cantilever structure of the balcony was reestablished using glass fiber-reinforced polymer (GFRP) rebar and a ConServ Epoxy restoration system. The damaged cantilevers were cut back an acceptable surface and the GFRP bars were doweled into the existing timbers and the new timbers. The bars and timber faces were prepared using ConServ 552 Epoxy, a multipurpose structural epoxy adhesive. Paul Marlowe of Marlowe Restorations LLC and the owner of ConServ Epoxy LLC, conducted the cantilever reconstruction process. The railing design by Christopher Williams Architects replicated the original railing from available photographs.

Architect: Christopher Williams Architects, LLC

Contractor: Marlowe Restoration LLC

Supplier: ConServ Epoxy LLC

By GNCB 26 May, 2017

Wright Laboratory was recently renovated to transform it into a center for research on neutrinos and dark matter. GNCB’s work as structural and geotechnical engineer on this project included the design of a new steel-framed first floor and mezzanine supported with new concrete foundations. The first floor system was installed in phases in order to brace the thick earth berm at the exterior of the building prior to the remainder of construction. The engineering design featured isolated portions of framing for new vibration-sensitive research equipment.

Architect: Christopher Williams Architects, LLC

Contractor: Shawmut Design and Construction


Watch a short documentary on the history and transformation of Wright Laboratory:

By GNCB 22 May, 2017

GNCB believes that it is important to foster students’ interest in the fields of structural engineering, geotechnical engineering, and historic preservation. The firm is proud of its internship program which supports students at both the high school and college levels. This summer, Ms. Eleanor Phetteplace of Roger Williams University’s (RWU) will be joining GNCB as an intern. Ms. Phetteplace is an Engineering major, with a specialization in civil engineering, and is minoring in both Historic Preservation and in Mathematics.

Ms. Phetteplace is an active member of RWU’s Honors Program and is involved in a number of extracurricular activities including the American Society of Civil Engineers, Engineers Without Borders, and the Society of Women Engineers, of which she is vice president. Additionally, Ms. Phetteplace is engaged in an extended internship with the Bristol Historical and Preservation Society conducting research on the Bristol Industrial Park (c. 1864), a historic rubber and aluminum factory integral to Bristol’s economic heritage.

While interning at GNCB, Ms. Phetteplace looks forward to exploring the relationship between structural engineering and historic preservation through technical assignments and field work. She will also be assisting in the design of new structures and in construction administration. We are excited to have her join us until she returns to RWU for her junior year in the fall.

By GNCB 17 May, 2017

GNCB was honored by the CT Society of Civil Engineers (CSCE) at the 2017 Achievement in Civil Engineering (ACE) Awards Ceremony this May for the Adaptive Reuse of Holdredge Garage in Westerly, RI. The project received both the Structural Award of Merit and the Sustainability Award of Merit .

The historic Holdredge Garage (c. 1885), now Lanphear Livery, in Westerly, RI was built and enlarged in several stages in the late 19th century as a livery stable and staff housing for the Watch Hill summer hotel and cottage resort. In the early 20th century, the building was converted from a livery to automobile storage and repair. The Rhode Island Historical Preservation and Heritage Commission approved the adaptive reuse of the property as a RI Historic Tax Credit project in 2013.


GNCB’s structural engineering, geotechnical engineering, and historic preservation groups serviced this project starting with the condition assessment of the six conjoined structures, through design for the complex’s stabilization and adaptive reuse, and through construction.

The project present numerous challenges including:

1.  The site’s location within a flood plain;

2.  The long abandonment of the complex leading to deterioration in structural elements;

3.  Stabilizing the structure for hurricane-level wind forces;

4.  The change of use associated with adapting the barn-like structure for public use; and

5.  Maintaining the historic integrity of a prominently-located building contributing to the Watch Hill Historic District’s historic designation


Holdredge Garage is now a significant contributor to the economic prosperity of Watch Hill. It provides 21,000 square feet of reclaimed rentable space and storage. The ground floor houses three retail units and an atrium. The upper floors provide apartment housing to be rented to Watch Hill’s hotels’ staff. The cost of construction for this project was approximately $6 million.

Architect: NewPort Architecture, LLC

Contractor: Pariseault Builders

By GNCB 27 Apr, 2017

David Freed , GNCB Geotechnical department head, recently attended an informative one-day geotechnical workshop on the Connecticut Valley Varved Clay (CVVC). About 60 geotechnical professionals attended the workshop, sponsored by the Connecticut Society of Civil Engineers , which was held at the University of New Haven. Dr. Stanley Bemben - consultant, former UMASS professor, workshop organizer, and primary speaker - put together a team of seven speakers from the university and design professional environment to address topics on geologic aspects, characteristics and behavior, the “cementation” phenomenon, construction aspects. Several case studies were presented as well.

The CVVC deposit, which ranges up to about 100 ft. thick, is a direct result of the yearly deposition of alternating thin layers of silt and clay within the former Lake Hitchcock. This glacial lake, which is reduced in size and now approximately aligns with the Connecticut River, extends from about Hartford CT to the northern USA/Canada border.  A clay and silt layer represent one year’s cycle of time; the number  of cycles, much like the rings of a tree, are studied to provide a realistic estimate of the age of the deposit. The surface of the clay is stiff (desiccated crust), a result of exposure to drying once the lake was drained, however the majority of the deposit is very soft which exhibits large settlements when stressed above its maximum past pressure. In his presentation, Dr. Bemben states that “the silt/clay deposit has an inherent “cementing” due to precipitation of cementing agents and an ongoing time dependent aging process”. One net effect of the cementation process results in an under estimation of compressibility properties when interpreting one-dimensional consolidation tests using classical Terzaghi analysis.  

The CVVC deposit is well-studied, however its compressibility and strength characteristics vary considerable between locations.   One and two story structures can often be supported on shallow spread footing foundations, provided there is an upper alluvium sand or the surface of the CVVC has a desiccated crust. However taller structures often requires improvement of the CVVC by preloading that is aided by wick/sand drains, or by driving deep piles to the underlying dense glacial till or rock.   Due to the variable despite characteristics, tall structures supported on top of the CVVC requires a program of laboratory index, compressibility, and strength testing to document conditions at a specific site.

Working within the CVVC deposit can also be challenging. The soils are generally sensitive, requiring careful field procedures to preserve its intact condition, bearing capacity and strength. Workmen can easily disturb soils to the extent that they can no longer support the specified soil bearing.  

David Freed can be contacted at .

By GNCB 12 Apr, 2017

The Church of St. Michael the Archangel celebrated a major milestone in construction this April with the installation of the first timber truss. To commemorate this point in construction, the Church invited the St. Michael community and the project design and construction teams to attend a ceremony in which Bishop Michael Cote of the Diocese of Norwich blessed the first truss before its installation.

The parish decided to reconstruct their Church following GNCB’s discovery of extensive failures in the original Church’s scissor roof trusses in spring 2012. The new Church is designed to replicate the original’s layout and appearance, while providing major improvements to accessibility, community space, and aesthetics.

As Engineer-of-Record for this project, GNCB is responsible for the improvements and modifications to the existing foundations, reinforcement of the first floor framing, design of the lateral system of the Church using cold-formed-steel construction, and design of the Church balcony and rear addition. To-date, installation of concrete and steel in the lower level of the Church is complete. Construction now moves above ground with the installation of steeple steel and the timber trusses.

See the photos and video below to learn more about this project’s backstory and progress as well as the Truss Blessing Ceremony.

Architect: Geddis Architects

Construction Manager: Petra Construction

Timber Frame Designer and Contractor: Vermont Timber Works

Watch the Truss Raising Video

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