Cantilevered construction is one of today’s stunning architectural features and structural elements. Generally, it’s a protruding beam or plate that extends horizontally and is supported on one side. Apart from its aesthetic look, the cantilever provides more space and durability to the overall structural design.
If you’re planning to incorporate cantilevered construction into your property, this article discusses a guide to cantilevered construction. So, read on!
Introduction to Cantilevers
A cantilever is a structural element that extends horizontally and is supported at only one end, known as the fixed end. The other end, referred to as the free end, is not supported and is subject to various loads, including weight, wind, and seismic forces. Cantilevers are commonly used in construction, engineering, and architecture to create unique and functional structures, such as cantilever bridges, cantilevered buildings, and cantilever arms extending from a main structure. The use of cantilevers allows for the creation of longer spans and more efficient use of space, making them a popular choice for builders and architects.
Uses And Needs Of Cantilever Beam Construction
Cantilevered designs are evident in public spaces. Cantilevered designs create overhanging structures without the need for additional support, enhancing both functional space and aesthetic appeal. A balcony protruding from a building is a classic example of a cantilevered construction. Cantilevered designs are also significant in bridge construction, allowing for long spans without mid-supports. Another example of this structure is a footbridge. It can also be a canopy, a runway for oversized vehicles, or a cantilever beam in various structural applications. A cantilevered structure must be designed with stability and safety in mind, considering factors like material selection and load distribution. It can be a shelving unit, such as Stackit cantilever racking. Cantilevers are also used in architectural elements such as bridges, roofs, and floors, contributing to efficient design and space utilization. In addition, its beam support must be able to withstand the weight it carries, especially in structures with significant overhangs like bridges and balconies. Cantilever designs are also popular in residential construction, enhancing space efficiency and aesthetic appeal in homes. Cantilevered stairs are another innovative application, providing a visually striking effect while ensuring safety through hidden structural frameworks. In other words, cantilevers can be used anywhere, often integrated with other structural components like beams and trusses. Cantilevered walkways provide both functional and aesthetic benefits, creating protected spaces that enhance the visual appeal of buildings.
If you’re new to cantilevered construction, you may need to understand that since it extends from a single support, it needs a highly durable foundation. In addition, its beam support must be able to withstand the weight it carries. This won’t be a problem in canopies and similar structures, but this must be the utmost consideration for cantilevered bridges, runways, and balconies.
Types of Cantilever Structures
There are several types of cantilever structures, including simple cantilevers, compound cantilevers, and cantilever trusses. A simple cantilever is a single beam or structural element that extends from a support, while a compound cantilever consists of two or more cantilever arms extending from opposite sides of a support. Cantilever trusses are composed of multiple beams or structural elements that work together to provide support and stability. Cantilever bridges, for example, often consist of three cantilevers, with two cantilever arms extending from opposite sides of a central support. The choice of cantilever type depends on the specific requirements of the project, including the length of the span, the type of load, and the desired level of stability.
Cantilever Design
Cantilever design involves careful consideration of various factors, including material selection, load distribution, and structural reinforcement. The design of a cantilever must take into account the weight and type of load that will be applied to the structure, as well as any external forces, such as wind or seismic activity. The use of cross-bracing and other forms of reinforcement can help to resist twisting forces and provide additional stability to the structure. Cantilever design also involves the selection of suitable materials, such as concrete, steel, or wood, and the consideration of factors such as thickness, anchored systems, and supporting structures. Engineers and architects must work together to create a cantilever design that is both functional and aesthetically pleasing.
Safety Considerations
Safety considerations are critical when designing and constructing cantilever structures. The primary concern is the risk of collapse or failure, which can be caused by a variety of factors, including inadequate design, poor construction, or excessive loading. To mitigate this risk, builders and engineers must ensure that the cantilever is properly supported and reinforced, and that all loads are carefully calculated and distributed. Regular inspections and maintenance are also essential to ensure the ongoing safety and stability of the structure. Additionally, cantilever structures must be designed and constructed to resist wind and seismic forces, which can cause twisting and bending stresses that can lead to failure.
Advantages Of Cantilever Bridges Construction
Cantilevered construction has many advantages, making it one of the reliable structural designs contractors suggest and homeowners choose. The forces and effects created by cantilevered structures highlight the importance of material selection for durability and strength. Notable examples of cantilever construction include the Tacoma Narrows Bridge and the San Francisco-Oakland Bay Bridge. These advantages include the following:
- Simple To Construct
Since this design requires minimal building support and space, it’s more manageable to construct than other elements, while effectively resisting the force of applied loads. Cantilevers can be incorporated into various architectural designs to enhance visual appeal and functionality. Cantilever designs are particularly useful in bridge construction, allowing for long spans without supports in the middle. Cantilevers can be constructed similarly to other structural components, such as beams and trusses. In many cases, it’s only attached to a wall or similar foundation before being extended. However, there are also complex types of cantilevers that are more challenging to construct, especially those with significant overhangs. Usually, these are constructed in parts or short pieces, such as bridges and railroad decks.
- High Architectural Value
Cantilevered construction is generally open for various designs. Because of this, it can be a solid framework for overhead viewpoints, modern rooftops, and protruding fences. It can also create tradition-defying architectural designs that add value to a construction project.
- Better Span
Cantilevered designs can generally provide better space on top and under it. However, in extending their length, workers should ensure that the load is distributed throughout the beam or plate. To ensure structural integrity, the extension should follow the 2:3 ratio, or the 2X joists should extend back into the floor of a minimum of eight feet.
- Durable
Cantilevered elements are typically durable because of their rigidness and depth. Unlike simply supported beams, cantilevers are anchored at one end, providing unique structural benefits. What’s essential is the stable fixed side, strengthened by the wall or beam. Reinforcement on the fixed side is also exceptional support to press the extension. Cantilever trusses are often used in bridge construction to span long distances and provide stability.
As a result, they can bear the weight of oversized vehicles, such as trains and trailers. Their structural integrity is generally above-average and has a longer lifespan than many structural designs and elements.
- Sustainable Expansion
Since the cantilever is protruded, it can be extended further. However, before considering expanding and outspreading the element, workers must ensure that the fixed end can support the extension. Ignoring this fact can lead to breaking up the portion or the entirety of the extension.
- Manageability
Many cantilevered construction projects are finished in a shorter timeframe because they don’t require a lot of falsework, such as temporary columns. Because of this, contractors can proceed with working on the cantilevered span or extension. Because of these qualities, cantilevered designs are used in flood-prone rivers and deep gorges.
Cantilevered bridges, on the other hand, are preferred and built over challenging roads and turns because they allow better navigation. In the context of cantilevered bridges and roads, assembled sections can be lifted and moved for better movement in the bridge, road, or the space it’s built.
Disadvantages of Cantilevered Construction
Just like most structural designs and construction, cantilevered constructions also have disadvantages. Here are some of them:
- Expensive
Compared to regular constructions, beams, and extensions, cantilevered constructions may be more costly. This is because of the more complex structural design and labour it requires. Aside from these, you may have to pay for expensive materials, such as steel beams and reinforced concrete.
- Major Deflections
Because of its structural design, a structure only supported at one end, cantilevered constructions are subject to large deflections. This deflection happens when the neutral axis becomes a curve, especially when the structure is subjected to loads and stresses. To mitigate this risk, builders and engineers must ensure that the cantilever is properly supported and reinforced, with all loads carefully calculated and distributed. Cantilever structures must be designed and constructed to resist wind and seismic forces, which can cause stresses at the unsupported end.
Challenges in Cantilever Construction
Cantilever construction presents several challenges, including the need for temporary support during construction, the risk of twisting and bending stresses, and the difficulty of ensuring adequate stability and safety. The use of cantilevers can also create access challenges, particularly during construction, and may require the use of specialized equipment and techniques. Furthermore, cantilever structures can be sensitive to changes in temperature and humidity, which can cause expansion and contraction of the materials, leading to stresses and potential failure. Despite these challenges, cantilevers remain a popular choice for builders and architects due to their unique aesthetic and functional benefits, and their ability to create longer spans and more efficient use of space. By carefully considering the design, materials, and construction techniques, engineers and architects can create cantilever structures that are both safe and functional.
Conclusion On Structural Components
Cantilevered construction is one of the most unique architectural and structural designs today. Many opt for it because of its aesthetic quality, such as protrusion and unlikely curve in some cases. Apart from this, the cantilever’s long line of advantages, including durability and simplicity, make it a top-notch option for the structural element. However, keep in mind that you should also consider its disadvantages. This way, you’re making an informed decision when incorporating this construction into your property. Moreover, you may also seek the advice of a seasoned engineer or contractor, especially when talking about extending the element or widening the span.
