Fences and retaining walls play an important part in structural engineering. Fences can be a quick way to seal off a perimiter and doesn't require much foundational perp work. Retaining walls are a great way to create barriers using steep or unlevel foundations. Since fences and structural walls are important for structural engineering, HH Consulting understands the science and engineering that goes into building a good fence or retaining wall which are often a part of residential and commercial projects.
We build sturdy and reliable fences
Fences have been used for centuries by many different civilizations but a good fence still needs an engineer to build it right. A fence is a structure used to enclose an area of space, typically outside your house or property. This structure uses posts that can be connected by boards, wire, rails or nettings to create a physical barrier. A fence is slightly different from a wall that it doesn't rely on having a solid foundation along it's entire length.
Traditional alternatives to fencing includes a ditch, sometimes filled with water, forming a moat. However, these alternatives aren't common because fences are a cheaper and faster structure to build and serves virtually the same purpose.
Fences and function
The type of fence you need has probably already been engineered, here is a list of fences by function, since fences are essentially a barrier to keep things in or out they can be built to serve specific functions.
Agricultural fencing is used to keep livestock in and/or predators out.
A blast fence is a safety device that redirects the high energy exhaust from a jet engine.
A sound barrier or acoustic fencing is used to reduce noise pollution.
Crowd control barrier
Also known as the French barrier or bike rack, crowd control barriers are commonly used at many public events to control crowd traffic.
Privacy fencing is used to provide privacy and security.
Temporary fencing is used to provide safety, security, and to direct movement wherever temporary access control is required. This is especially important for building and construction sites.
Perimeter fencing is used to prevent trespassing or theft and/or to keep children and pets from wandering away.
Decorative fencing is used to enhance the appearance of a property, garden or other landscaping.
Boundary fencing can be used to fence off a piece of real property.
Newt fencing, also known as amphibian fencing, drift fencing or turtle fencing is a low fence of plastic sheeting or similar materials used to restrict movement of amphibians or reptiles.
Pest-exclusion fencing is used to exclude certain types of animal pests from an enclosure.
Pet fencing is simply used for pet containment.
Pool fencing is used to create barriers around pools or bodies of water to protect children, pets, or non swimmers from drowning.
A snow fencing is very similar to sand fencing as they serve the same function, which is a barrier that forces windblown, drifting snow/sand to accumulate in a desired place.
A balustrade or railing is a fence to prevent people from falling over an edge, most commonly found on a stairway, landing, or balcony. Railing systems and balustrades are also used along roofs, bridges, cliffs, pits, and bodies of water.
Different types of fencing requires different construction methods. Here's a list of construction methods by different fencing type.
Brushwood fencing is a fence made using wires on either side of brushwood, to compact the brushwood material together.
Chain-link fencing is wire fencing made of wires woven together,
Close boarded fencing
Close boarded fencing is a strong and robust fence constructed from mortised posts, arris rails and vertical feather edge boards.
An expanding fence or trellis is a folding structure made from wood or metal on the scissor-like pantograph principle, sometimes only as a temporary barrier.
There are different types of hedge fencing, these are:
- Cactus fence
- Hedgerows of intertwined, living shrubs (constructed by hedge laying)
- Live fencing is the use of live woody species for fences
- Turf mounds in semiarid grasslands such as the western United States or Russian steppes
Hurdle fencing is a structure made from moveable sections.
A pale fence is composed of pales. Pales are vertical posts embedded in the ground, with their exposed end typically tapered to shed water and prevent rot from moisture entering end-grain wood - joined by horizontal rails, characteristically in two or three courses. This method is also known as post and rail fencing.
A palisade, or stakewall is made of vertical pales placed side by side with one end embedded in the ground and the other typically sharpened, to provide protection. Typically two courses of waler are added on the interior side to reinforce the wall.
Picket fences are generally a waist-high, painted, partially decorative fence.
Roundpole fences are similar to post-and-rail fencing but more closely spaced rails, typical of Scandinavia and other areas rich in raw timber.
A slate fence is a type of palisade made of vertical slabs of slate wired together. This type of fencing is commonly used in parts of Wales.
A Split-rail fence is made of timber, often laid in a zig-zag pattern, particularly in newly settled parts of the United States and Canada.
A caccary fence (named from Latin vaca - cow) is used for restraining cattle. This fence is made of thin slabs of stone placed upright, found in various places in the north of the UK where suitable stone is had.
A vinyl fence is a fence made using synthetic plastics, such as vinyl (PVC), polypropylene, nylon, polythene (polyethylene) ASA, or from various recycled plastics.
There are various types of solid fences, some of them are:
- Dry-stone wall or rock fence - often seen in agricultural evnironments.
- Stockade fence - a solid fence composed of contiguous or very closely spaced round or half-round posts, or stakes, typically pointed at the top. A scaled down version of a palisade wall made of logs, most commonly used for privacy.
- Wattle fencing - a fence made up of split branches woven between stakes.
There are different types of wire fences out there, some of them are:
Wrought iron fencing
- Smooth wire fence
- Barbed wire fence
- Electric fence
- Woven wire fencing - can have many designs, from fine chicken wire to heavy mesh "sheep fence" or "ring fence".
- Welded wire mesh fence
Wrought iron fencing is also known as ornamental iron.
We build strong and long lasting retaining walls
Retaining walls are foundationals walls used to support soil laterally and retaining that soil at different elevations on the two sides of the wall. Retaining walls are essentially designed to keep soil in place, creting a slope that would otherwise not form naturally. Retaining walls are typically structures that are used to bind soils between two different levels where the terrain has undesirable slopes or in areas where the land needs to be reshaped and engineered for specific functions like hillside farming or roadway overpasses.
A basement wall is also a type of retaining wall, but its more comoon term is called a cantilever retaining wall - a freestramdomg stricture without lateral support at its top.. Besides binding just soil, a retaining wall can be used to retain soil and water on opposite sides, such structures are more commonly known as seawalls or bulkheads.
Types of retaining walls
There are different types of retaining walls which use various aspects of structural engineering to make them physically viable.
Gravity walls are dependant on their mass and are made up of stone, concrete or other heavy materials, all to resist pressure from behind. Some gravity walls may have a 'batter' setback to improve their stability when leaning back toward the retained soil. Gravity walls can also be built for short landscaping walls, these are made from mortarless stone or segmental concrete (masonry) units.
A Cantilevered retaining wall is built using an internal stem made up of reinforced steel and casted concrete or mortared masonry. These structures cantilever loads unto a large footing, converting horizontal pressures coming from behind the wall to vertical pressuses on the ground below. Although these walls require rigid concrete footings often shaped in an inverted T, this type of wall uses much less material than a traditional gravity wall.
A sheet pile retaiing wall is normally used when there's soft soil in tight spaces. Sheet pile walls are constructed using a variaety of meterials which include steel, vinyl, aluminum, fiberglass or wood planks which are driven down into the earth. To have tall sheet pile walls you would need a tie-back anchor or "dead-man" placed into the soil a distance behind the face of the wall. This is then tied to the wall with a cable or rod and anchors are placed behind the potential place in the soil.
A bored pile retaining wall is built using an assembled sequence of bored piles which are proceeeded by removing any excess soil. Sometimes, a bored pile retaiing wall may have a series of earth anchors, reinforcing beams, soil improvement operations and a concrete reinforcement layer. Such construction methods usually need to be used in cases where sheet piling is a valid construction solution but where the vibration or noise generated by a pole driver are unacceptable.
Anchored retaining walls can be built using any of the types listed aboce but can also add additional strength to the structure using cables or other stays anchored into the rock or soild behind the wall. Typically the anchors are driven into the material using boring techniques - the anchors are expanded at the end of the cable, either using mechanical means or more often by inhecting pressurized concrete (which expands to form a bulb in the soil). This technique isn't used often due to its techniocal complexity and in cases where high stress loads are expected or if the wall needs to be thin and would be too weak to support the structure.
Alternative retaining techniques
There are different alternatives to building retaining structures - some have been around for a long time and often serve specific functions.
The soil nailing technique is used to reinforce soil slopes, excavations or retaining walls by inserting slender elements like steel reinforced bars. The bars are typically installed into a pre-drilled hole and then grouted in place. These bars are installed untensioned at a silight decline then a rigid or flexible facing or isolated soil nail heads are used on the surface to cap off the insertions.
There is many different syhstems that exist which don't consist of just the wall but reduce the earth pressure that acts directly on the wall itself. These techniques are typically used together with other wall types, though some may only use it for visual purposes.
Gabion meshes is a type of soil strengthening technique used when there is no outside wall. It consists of wire mesh boxes which are filled with rough cut stones or other similar material. The mesh cages reduce reduce internal movement and kinetic forces as well as erosive forces. Gabion walls are free-draining retaining structures and are typically built in locations where a lot of ground water is found. Aside from this, some kind of management and control of ground water in and around retaining walls is still required and is very important.
Mechanical stabilization, also known as MSE, is a technique where soil is constructed with artificial reinforcing layers of horizontal mats known as geosynthetics, which are fixed at their ends. These mats offer added internal shear resistance that go beyond that of simple gravity wall structures. Other options can also include using steel straps which are also layered. This type of soil strengthening technique usually needs an outer facing wall in order to affix the layers to.
Some content and data found in this article was sourced from Wikipedia.