Structurally Sound: Definition, Use in Buildings and Bridges



Structurally sound means free from defects, flaws decay, and deterioration to the extent that structures or buildings accomplish their design. In terms of public infrastructures, structurally sound buildings lack imperfections that impact the desired use of a structure, so as not to endanger the safety, health, and welfare of the public.

In this article, you will learn about the process of ensuring a product is structurally sound, and its applicability to buildings and brides.

Structural Assessment Process

Building structures have to endure a lot of stress over their lifespan from natural disasters to intense weather fluctuations. Over time, elements may wear down a building structure and play a vital role in diminishing the structural integrity of a building. Structural assessment of a building determines how much that building provides structurally soundness.

Development of local codes such as Structural Soundness and Maintenance of Industrial Structures ensure standardization. The applicability of building codes depends on the region of construction, the type of structure, and occupancy requirements. Most engineers utilize specialized software to analyze industrial buildings in terms of structural soundness.

The process of ensuring a structurally sound structure begins in design, continues via raw material compliance, and finalizes via finished product testing.

Design Process

In this step of the analysis, engineers evaluate the construction by designing a structure on the basis of material quality and strength. Engineers consider compressive strength, stress-strain curves, fatigue strength, and any design parameters prior to procuring material. When a material lacks published data on its endurance or strength limits, engineers may order tests.

Engineers may utilize various software tools during this phase to model and simulate stresses as per design requirements.

Building design via computer software
Courtesy: Arch Daily

Raw Material Requirements

Engineers specify specific tests for each raw material that goes into a structurally sound building, bridge, or other pieces of equipment. These tests may occur during the manufacturing of the material or integration of the material into the finished product. For instance, some specifications require concrete to undergo slump and strength testing whereas others specificy the grade of heat treatment requirements of raw steel.

Initial Inspection Process

Structural engineers conduct an initial visual inspection of building premises. This visual check varies by engineer, location, and product. Visual inspections provide notoriously limited scopes as the scope only includes visually present items.

Finished Product Testing

Construction testing of products and materials from construction depends upon the locality of buildings. The most commonly employed testing process is the ultrasonic pulse velocity test that assess the feasibility and structural soundness of a building. Other common tests include rebound hammer test, carbonation test, concrete chemical analysis, and cover meter studies.

These tests exist as part of an overall maintenance plan developed by the asset owner and subcontractors. Also, the testing output provides empirical data that determines whether a structure meets structural soundness requirements.

Structurally Sound Buildings

Every industrial structure’s foundation, floor, wall, ceiling, and roof requires proper construction and maintenance. Thus, assurance occurs that all occupied rooms and other interior areas are weather-tight, watertight, rodent-proof, and fit for human use. Responsibility for this conformance falls on the responsible contractor – be it commercial roofers, industrial sheet metal providers, and/or responsible engineers.

Dowel rebar applies to new construction projects and rehabilitation of buildings. These short steel rods insert into adjacent joints of the concrete slab during the construction phase of a building. Moreover, these rebars allow for an appropriate amount distribution of loads. Dowel rebar allows the concrete to distribute the load to an adjacent concrete slab. These dowel bars help specifically when the traffic moves from one end of the slab to the start of another.

Structurally Sound Bridges

For a bridge to be structurally sound, the following considerations must apply:

  • All loads or forces that are likely to act on bridge structures require appropriate consideration. Such loads are dead, live, dynamic, machine vibrations, and earthquake forces.
  • The strength of materials like steel and concrete must fit design requirements and be of the appropriate grade.
  • Dimensions, reinforcement details, positions, concrete covers, and levels should follow the design requirements for a bridge according to standard codes like ISO-800, ISO-456.

Bridges design usually occurs via the Load and Resistance Factor Design (LRFD) specifications. LRFD specifies HL-93 loading. Moreover, design outputs report as metric tons or Rating Factor (RF).

The allowable stress design (ASD) provides an alternative to LRFD. Generally speaking, the LRFD method provides stronger structures for highly dynamic loads while ASD results in strong structures for more predictable loads. As such, engineers generally prefer LRFD when dealing with real world stress phenomena.

Load-Carrying Capacity of Bridges

The load-carrying capacity of a bridge relates to the “management and maintenance of roadways and bridges” according to the codes and load factors defined by AASHTO (1999). A bridge has the capability to carry a certain amount of load that can work under a specific load and over an estimated load, a bridge can fail. The factor of safety of a bridge calculates from the following equation:

A screenshot of a computer simulation

What Makes a Bridge Structurally Sound?

A truss bridge provides support for a certain load without bending, breaking, or moving. Thus, over the passage of time, the structural integrity of any structure erodes and the structural soundness of a bridge can decrease. The efficacy and safety of a bridge depend upon the strength of its supporting system. Each component of a bridge structure provides a structurally sound bridge with structural integrity.

TrussSpecific to truss bridges, bridge trusses are intended to bear tension or compression to handle dynamic loads.
CAPIt is set on the top of piles to disperse the weight of the bridge span.
PilePiles are concrete posts that are immersed into the ground or water to provide support.
BeamThese are the horizontal members that span over the length of two support vertical columns. Beams are the most visible part of bridges.
BentIt supports the beams and girders of a bridge. It is commonly made of steel or concrete and is placed transverse to the whole structure.
BearingBeams of a bridge rest on bearing to transfer weight from bridge to substructure. It also allows for changes in movement and temperature.
DeckDeck is the area of a bridge that is traversed by vehicles. It is usually made of concrete or asphalt slabs.

Truss bridges have certain advantages over other bridges as their provide higher strength and resistance to extreme conditions. However, these bridges require a lot of space, incur higher maintenance costs, and require complex construction methodology.