Many buildings constructed in the nineteenth century and earlier are timber-frame structures. Builders used plentiful old-growth timber and adapted European construction methods to the new world. While the behavior of timber braced frames are fairly complex, these buildings were built without the aid of structural engineering calculations and design standards. To ensure that the building was safe and useable, the builders could not deviate too far from their prior experience. As a result, historical timber-frame buildings follow common forms and floor plans. Even as light wood-frame construction began to replace timber framing in the late nineteenth and early twentieth centuries, vestiges of timber framing practice persisted.
While traditional timber frame structures and later light-frame wood structures have outward similarities, their structural behavior differs significantly, resulting in light-framed structures being more easily modified. What would be straightforward renovations in conventional light-frame wood construction may introduce complications requiring the involvement of a structural engineer in a timber frame structure. Continue reading “Structural Engineering Considerations of Renovating a Timber Frame Building”
As RJDCE was completing projects from late 2021, the 2022 construction season started quickly. The schedule coordination difficulties that have come to characterize the COVID-19 era in the architecture, engineering and construction industry continued to plague multiple projects. After a few months of an abnormally high proportion of proposals becoming projects and additional services being required for ongoing projects, the practice was severely overloaded. Despite contract labor recruitment efforts to assist with field work and drafting, the mounting backlog and difficulty scheduling outside service providers sharply limited the practice’s ability to meet the demand for services. As a result, a new approach to project selection was taken in which greater emphasis was placed on relationships with project stakeholders and the value RJDCE’s services could bring to a given project. In addition, greater focus was given to balancing types of projects in terms of practice area, phase of construction and deliverables required. Ultimately, RJDCE offered proposals for fewer new projects in 2022 than in 2021, but the projects accepted were typically larger and were better suited to RJDCE’s expertise. Continue reading “The Year In Review: 2022”
Soil and rock anchors, sometimes collectively referred to as ground anchors, are tension elements consisting of a tendon composed of prestressing strands or a reinforcing steel bar that is grouted in a borehole. Ground anchors derive resistance to load through the bond strength between the grout, the tendon and the soil or rock in which it is installed.
Ground anchors can be used in temporary or permanent applications, can be installed at angles ranging from vertical to almost horizontal, and are often prestressed to control the deflection of the structure that they support. They were first used in the United States for temporary excavation support applications over 50 years ago. Subsequently, the use of permanent ground anchors has become commonplace in transportation projects. They are often used in non-building structures but are perhaps underutilized in the building sector despite being an economical and adaptable means of resisting lateral load effects on foundations. Continue reading “Soil and Rock Anchors for Resisting Lateral Loads in Buildings”
With high property values and space at a premium, construction in cities and urban suburbs usually involves redeveloping or expanding the built-up area of a previously occupied lot or collection of lots in an established neighborhood. To maximize the utilization of land, projects are often designed such that the built-up area, including buildings, accessory structures, parking and landscaping are built-up to the property line.
In some circumstances, the owner of a project or their contractor may request that access to perform work on abutting properties so that the project can make the greatest use possible of the buildable area on the site. This frequently occurs in major cities where buildings extend to the boundaries of the lots on which they are built. When a new building is constructed along a lot line shared with another building, it is often necessary for the constructor to perform work on the adjacent structure to temporarily or permanently protect it from damage. Underpinning of foundations, roof protection, weatherproofing and stabilization of former party walls, removal of encroachments, and installation of flashing between buildings are common examples. Continue reading “Construction Beyond Boundaries”
Halfway through spring – according to the calendar more than the weather – the 2022 construction season is off to another fast start. This is one of the busiest times of year for Richard J. Driscoll, Consulting Engineer (RJDCE) and that trend continues this year. Like a lot of firms, RJDCE has a growing backlog and is experiencing delays and cost increases from outside services and vendors. The lack of available schedule “float” every week and frequent disruptions result in unpredictably long delivery times for certain services. Continue reading “Spring 2022 News”
Richard J. Driscoll, Consulting Engineer (RJDCE), a diverse structural and foundation engineering and construction risk management practice in Lebanon, New Hampshire, is seeking an independent contractor to serve as a project assistant or entry-level engineer on a project-by-project basis. The immediate need is for someone to accompany an experienced engineer to observe, measure and document existing structures in connection with structural condition assessments and forensic investigations. Depending on the contractor’s capabilities and interests, opportunities may arise to draft or proofread reports, perform or check structural engineering calculations and assist with the preparation of CAD drawings.
Desired qualifications: Two years minimum experience in the architecture/engineering/construction industry or a combination or a related degree and internship and/or professional experience. Must be proficient in speaking and writing in English, preferably with a working knowledge of building technology and construction terminology. Experience with technical writing, CAD and structural design would be ideal.
Location: New Hampshire or the Upper Valley region of Vermont. Most projects are in New Hampshire and Vermont. Contractors in other locations served by RJDCE would be considered, but travel and lodging reimbursement may not be available for most projects.
Compensation: The basis and amount of payment will vary by project.
If not a “return to normal” or the arrival of a “new normal”, 2021 brought another busy and record-setting year for Richard J. Driscoll, Consulting Engineer (RJDCE). The year was characterized by more regularity and fewer notable milestones. However, it set the stage for continued progress and perhaps some greater advancements in 2022. Continue reading “2021 Year in Review”
It is early in the investigation, of course, and as I have said before, it is not useful to attempt to draw conclusions immediately after a failure. Publicly available information is likely incomplete, may include imprecise or inaccurate information (there are slight discrepancies as to the time of the incident and early reporting identified the building as being three stories) and important details can get lost in the reporting process. More will be learned as the destroyed building is disassembled and removed. More yet will be learned in the course of the litigation that will inevitably follow. I do not have any answers, but I have a lot of questions. Continue reading “Should a Building Blow Down During Construction?”
To the uninitiated, a lot of everyday building construction with wood framing and concrete foundations looks pretty similar. However, from a structural engineering design perspective, they could be quite different. Light commercial and multifamily buildings, as well as many custom homes, are more complex and subject to greater load demands and code requirements than simple one- and two-family homes. The design of some or most of the structural systems in these structures must be designed based on calculations so that they perform as required under the anticipated loads, rather than conforming to traditional practices prescribed by the residential code. It is normal for the construction documents for these projects to include structural engineering drawings to communicate to the contractor how engineered structural components and systems fit together.
In the residential and light commercial construction sectors, some contractors do not seem to know what to do with structural drawings. The apparent similarity of engineered construction to traditional residential construction results in certain contractors failing to understand how they are different. Not knowing what they are taking on, they may be less expensive than their more sophisticated counterparts and are more likely to secure projects with inexperienced owners. This doesn’t always end well. Continue reading “Will Your Contractor Read the Drawings?”