Eastern Engineering Group
STRUCTURAL ENGINEERING DIVISION
Additions can be extensions to existing buildings to create more functional space or they can also be detached buildings to an existing developed parcel of land, but additions do not always require structural changes to the existing dwellings. Structural framing systems depend on building use, clear spans and architectural requirements, but typically additions to existing structures require the use of starter columns and if necessary enlargement of existing foundations for new structural loading. Detached additions use the same structural framing systems as low/mid-rise buildings. Renovation involves making structural changes to existing dwellings in order to increase functional space which can be the strengthening of existing beams, columns and foundations. Since these types of structural modifications involve alterations to existing load-bearing members, often times when attaching to existing concrete members, drilling and epoxying is required to anchor-in new framing members for strengthening purposes.
There are various types of single family homes we have specialized in over the years, one of these types of homes are tract homes which are designed as a series of different models or home types for a specific land subdivision development. The typical structural framing for tract homes consists of conventional premanufactured wood trusses for gable or hip-end roofs, load-bearing reinforced masonry walls and monolithic or continuous wall foundations to provide a code-compliant yet cost-effective solution. Another type of SFH we specialize in are custom homes which are designed for a specific owner and who sets the maximum design and construction budget that is available for the project. These homes can have conventional wood framing or reinforced concrete floor slabs depending on the budget at hand and the structural soundness required. The last type of single family home that we design are spec homes. These homes are speculative homes that are designed with a particular client in mind and usually bring superior structural soundness and a larger construction budget.
Multi-family Home construction typically consists of Duplexes and Townhomes. Duplexes are structures that house two units within the same dwelling envelope, sometimes these units are a mirror image of each other about a central demising (party) wall that separates one unit from the other. Townhomes are usually adjoined by various units within the same dwelling envelope. The common structural framing system for both of these types of construction is premanufactured wood trusses for intermediate floors and roof framing or reinforced concrete flat slabs. These floor systems bear on reinforced masonry walls on continuous wall footings.
Structural repairs are often necessary due to aging conditions of an existing structure. These conditions could arise as a consequence of weather, exposition to elements, impact damage, rotting or corrosion depending on material type and exposure to environmental conditions and loads. In the case of reinforced concrete, severe exposure to sulfate environments can cause reinforcing bars to corrode through natural cracking of members in marine environments. Long-term loads can also introduce creeping effects that alter the magnitude of crack-widths that ultimately weaken load-bearing members to the point of possible collapse if left unrectified over time. Structural steel framing can often lose its hot-dip galvanization layer of protection on its surfaces and this eventually leads to decreased structural performance from corrosion of bolts and members after continuous exposure to ponding from rain, and warping of surfaces from fire damage. Wood framing such as joists, rafters, premanufactured wood trusses, load-bearing partitions, or posts can also suffer from fire damage although the most common cause of long-term deterioration is rotting or termite infestation.
Low-rise building designs include, but are not limited to, multi-story commercial and residential structures, educational buildings, parking structures and warehouses. Typical structural framing systems depend on the owner’s requirements, project construction budget, site conditions, contractor preference and other factors. For residential buildings, there are various types of floor systems that can be implemented to provide the required structural performance such as concrete slabs plus metal decks on open-web steel joists, composite slab and joist systems, or thin reinforced concrete slabs on precast restressed concrete joists, hollow core slabs. In commercial and educational buildings, the previous structural systems are used in addition to reinforced concrete or post-tension slabs depending on desired clear spans and typical column spacing, supported on steel or reinforced concrete columns. Parking structures typically consist of precast concrete joists supported on soffit beams that bear on shop-precast or tilt-up panels or reinforced concrete columns. Warehouse facilities are typically framed with open-web steel joists which carry metal decks and are supported on reinforced masonry walls. Various types of foundations are implemented based recommendations by the geotechnical engineers which include deep (piles, caps, etc.) or shallow spread or continuous wall footings.
In addition to conventional structures, we also provide structural design services for specific-use structures such as, but not limited to, gymnasiums, air-traffic control towers (ATCTs) and prefabricated building foundations. Typical structural framing systems for gymnasiums are structural steel columns supporting long span open-web steel joists to achieve spans in excess of 100 feet for sports courts and training areas. Air-traffic control towers employ different structural systems that vary from precast or tilt-up panels for gravity load-carrying members to structural steel framing or hollow core precast slabs, being contingent with its design requirements relating to location environmental loads such as seismic or wind forces and federal requirements/specifications. Miscellaneous structures include foundations for prefabricated steel buildings whose design is commonly isolated foundations and base anchorage to them.