Cantilever Retaining Walls

Cantilever retaining walls are constructed of reinforced concrete. They consist of a relatively thin stem and a base slab. The base is also divided into two parts, the heel and toe. The heel is the part of the base under the backfill. The toe is the other part of the base.

Counterfort Retaining Walls

Counterfort retaining walls are similar to cantilever walls except they have thin vertical concrete webs at regular intervals along the backside of the wall. These webs are known as counterforts.

Counterfort retaining walls:

Gravity Poured Concrete Retaining Walls

Semi-Gravity Retaining Walls

A specialized form of gravity walls is a semi-gravity retaining wall. These have some tension reinforcing steel included so as to minimize the thickness of the wall without requiring extensive reinforcement. They are a blend of the gravity wall and the cantilever wall designs.

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Four Types of Concrete Retaining Walls - The Concrete Network

GABION RETAINING WALL SYSTEMS ARE MONOLITHIC GRAVITY MASS STRUCTURES THAT ARE IDEALLY SUITED FOR EROSION CONTROL APPLICATIONS AND FOLLOW STANDARD DESIGN METHODS FOR GRAVITY AND MSE RETAINING WALLS.

NOTE: THE FOLLOWING INFORMATION IS PROVIDED AS A GUIDE TO ASSIST CONTRACTORS AND DO-IT-YOUR-SELFERS IN THE PROPER CONSTRUCTION OFGABION RETAINING WALLS. THE PHOTOS AND ILLUSTRATIONS SHOWN ON THIS WEBSITE ARE EXAMPLES OF TYPICAL MULTI-COURSE GRAVITY RETAINING WALLS.THIS CONTENT IS PRESENTED FOR GENERAL INFORMATION PURPOSES ONLY AND SHOULD NOT BE TAKEN AS A SUGGESTED DESIGN OR PROFESSIONAL ADVICE FOR BUILDING YOUR WALL.WE ALWAYS RECOMMEND THAT YOU CONTACT A LOCAL PROFESSIONAL ENGINEER TO EVALUATESOIL FOR GABION WALL DESIGN ANDBASED ON A CERTIFIED GEO-TECHNICAL SOIL REPORT OF THE SITE LOCATION.

EXAMPLE PHOTOS OF TYPICAL MULTI-COURSE RETAINING WALLS:

GRAVITY RETAINING WALLS

Gabion wall base width relative to wall heightThe base width of a gabion gravity retaining wall is directly related to the height of the wall. As the wall height increases, the base of the wall must become wider to ensure structural stability. We have provided the diagrams below to illustrate a starting point for design analysis to determine the base width relative to the wall height.

A conservative rule-of thumb value of base width = 2/3 wall height.

Note: A professional stability analysis may determine that the gabion gravity retaining wall base width could be less or greater than the 2/3 wall height rule.

GABION GRAVITY WALL SIZES & DIMENSIONS

DURA-WELDand DURA-FLEX gravity retaining walls can be designed and constructed up to approximately 30, however due to the configuration of gabion gravity retaining walls their best suited for wall heights of 18 or less. For wall heights of 18- 36 see the Stable Slope Section of this web site.

Gabion wall base width relative to wall height base width of a gabion gravity retaining wall is related to the height of wall so as the wall height increases the basebecomes wider to ensure structural stability. Below is a suggested diagram to illustrate a starting point for design. A typical conservative value of base width = 2/3 wall height.

*** A stability analysis may determine that the gabion gravity retaining wall base width be less than or greater than 1/2 - 2/3 wall height.

TYPICAL SIZES & DIMENSIONS - GABION ROCK FILLINGDURA-WELDTMGabions: 3" x 3" square mesh openings - 4" - 8" angular shaped rocksDURA-FLEXTM Gabions: 3-1/4" x 4-1/2" - 8x10cm hex shaped mesh openings. Fill with 4" - 8" angular shaped rocks

DURA-FLEXTM Gabions: 2-1/2" x 3-1/4" - 6x8cm hex shaped mesh openings. Fill with 3" - 6" angular shaped rocks

Specific gravity required for the rock fill shall be determined by the design and specified by the design engineer. Specific gravity for rock fill material shall be no less than 2.5

Unit weight of gabion rock fill:TYPE OF ROCK LBS/CUBIC FT

BASALT 180GRANITE 160LIMESTONE 138SANDSTONE 140

Unit weight of gabion stone fill- based on a porosity of 0.30 or 30%SPECIFIC GRAVITY OF MATERIALSBASALT 3.0BRICK 2.0BROKEN CONCRETE 2.4GRANITIE 2.7LIMESTONE 2.5SANDSTONE 2.2TRAP ROCK 2.7

GENERAL DESIGN CONSIDERATIONS - Foundation PreparationGabion gravity retaining walls are typically placed directly on a graded soil foundation. To increase the bearing capacity, minimize differential settlement, and/or allow for additional drainage, a base layer of granular stone fill with consistent gradation ranging from to1-1/2"may be placed and compacted to local standards 6 18 in depth.

Foundation Grade & Wall batterIt may be determined, through a stability analysis, that additional stability of the gabion gravity retainingwall may be required to achieve acceptable factors of safety from sliding. Options prior to enlarging the gabion wall cross section for additional stability is to excavate and bury half of the first course baskets and erectthe gabion gravity retaining wall on a 5 - 6degree batter towards the retained slope. This will require the foundation soils to be graded and compacted to accommodate for the specified wall batter.

GEO-TEXgeo-textile filter fabric is a vital component of any gabion retaining wall project. The rock voids within the gabion baskets allows for free drainage of the retained soils and requires a filter fabric be placed between the gabion wall and the backfill soil interface. The geotextile filter fabric will minimize hydrostatic pressure andprevent loss of soil during drainage and drawdown.Gabion gravity retaining walls constructed without the placement of filter fabric will have a tendency to incur a loss of retained soils and grade elevation behind the gabion wall. The type of backfill soil specified will determine the type, and placement of the geotextile filter fabric.

LayoutTo provide the maximum resistance to soil forces the gabion baskets shouldbe placed with the length dimension of the gabion unit running from the back of the gabion wall to the front face of the gabion wall. This will result in the internal diaphragms being placed perpendicular to the wall face and parallel to soil thrust. When gabion units areplaced with the length dimension of the gabion unit running parallel with the length dimension of the wall the vertical seams shall be offset.

Compression LoadsFor gabion gravity retaining walls that are 15 30 in height the gabion basket foundation and bottom courses shall be placed in 1.5 vertical lifts to better absorb the compression and shear stresses.

Gabion Wall Face ConfigurationGabion retaining walls can be designed and configured with a stepped front face or a smooth front face. When utilizing a gabion wall with a smooth front face, the gabion wall should be placed on a 5-6 degree batter and is not recommended for walls above18 high. Gabion walls with a stepped front face shall have a minimum 1-1.5 horizontal set back for each 3 vertical lift.

Gabion Wall HeightGabion gravity retaining walls can be designed and constructed up to approximately 30, however due to the configuration of gabion gravity retaining walls their best suited for wall heights of 18 or less. For wall heights of 18- 36 consider two separate walls divided by a level plateau or see the Stable Slope Section of this web site.

Gabion Wall - Base width relative to wall heightThe base width of a gabion gravity retaining wall is related to height of wall. As the wall height increases the base of the wall becomes wider to ensure structural stability. We have provided the diagrams above to illustrate a starting point for design analysis to determine the base width relative to wall height. A conservative value of base width = 2/3 wall height. A professional stability analysis may determine that the gabion gravity retaining wall base width be less than or greater than - 2/3 wall height. NOTE: All the above examples are for information only and not to be considered design recommendations.The information provided in the above examples including geo-technical data, dimensions and site conditions are assumptions made by manufacturer and should be reviewed and certified by a Professional Engineer. Please check Local, State and Federal requirementsLINK TO RETAINING WALL SOFTWARE >>>

http://www.geotechnicaldirectory.com/page/software/retaining_wall_design_.html___________________________________________________________

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RETAINING WALLS - Gabion Supply

A retaining wall is a structure that retains (holds back) any material (usually earth) and prevents it from sliding or eroding away. It is designed so that to resist the material pressure of the material that it is holding back.

An earth retaining structure can be considered to have the following types:

It is that type of retaining wall that relies on their huge weight to retain the material behind it and achieve stability against failures. Gravity Retaining Wall can be constructed from concrete, stone or even brick masonry. Gravity retaining walls are much thicker in section. Geometry of these walls also help them to maintain the stability. Mass concrete walls are suitable for retained heights of up to 3 m. The cross section shape of the wall is affected by stability, the use of space in front of the wall, the required wall appearance and the method of construction.

Reinforced concrete and reinforced masonry walls on spread foundations are gravity structures in which the stability against overturning is provided by the weight of the wall and reinforcement bars in the wall. The following are the main types of wall:

A cantilever retaining wall is one that consists of a wall which is connected to foundation. A cantilever wall holds back a significant amount of soil, so it must be well engineered. They are the most common type used as retaining walls. Cantilever wall rest on a slab foundation. This slab foundation is also loaded by back-fill and thus the weight of the back-fill and surcharge also stabilizes the wall against overturning and sliding.

Counterfort walls are cantilever walls strengthened with counter forts monolithic with the back of the wall slab and base slab. The counter-forts act as tension stiffeners and connect the wall slab and the base to reduce the bending and shearing stresses. To reduce the bending moments in vertical walls of great height, counterforts are used, spaced at distances from each other equal to or slightly larger than one-half of the height Counter forts are used for high walls with heights greater than 8 to 12 m.

Mechanically stabilized earth walls are those structures which are made using steel or GeoTextiles soil reinforcements which are placed in layers within a controlled granular fill. Reinforced soils can also be used as retaining walls, if they are built as:

This category covers walls which use soil, reinforced with reinforcing bars, to provide a stable earth retaining system and includes reinforced soil and soil nailing.

Constructing a soil nailed wall involves reinforcing the soil as work progresses in the area being excavated by the introduction of bars which essentially work in tension, called Passive Bars. These are usually parallel to one another and slightly inclined downward. These bars can also work partially in bending and in shear. The skin friction between the soil and the nails puts the nails in tension.

The type of retaining walls that use both factors that is their mass and reinforcement for stability are called Hybrid or Composite retaining wall systems.

Any wall which uses facing units tied to rods or strips which have their ends anchored into the ground is an anchored earth wall. The anchors are like abutments. The cables used for tieing are commonly high strength, prestressed steel tendons. To aid anchorage, the ends of the strips are formed into a shape designed to bind the strip at the point into the soil.

Gabions are cages, cylinders, or boxes filled with earth or sand that are used in civil engineering, road-building, and military application and many others. OR Gabion elements fitted to geogrid 'tails' extending into supported soil. For erosion control caged rip-rap are used. For dams or foundation building, metal structures are used.

Steel sheet pile walls are constructed by driving steel sheets into a slope or excavation upto the required depth. Their most common use is within temporary deep excavations. They are considered to be most economical where retention of higher earth pressures of soft soils is required. It cannot resist very high pressure.

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Retaining Wall - Definition and Types of Retaining Walls ...

A collection of garden retaining walls and terraced gardens both residential and public.- Advertisement -

Terrace gardens date back to ancient times, and are still a beautiful butrarely seen luxury in modern times.

Contemporary terrace gardens and retaining walls tend to be much smaller and modest in most residential landscaping designs, and while some are works of masonry, others are simply stacked stones or concrete steps. We set out the 10 retaining wall materials here.

The majority of the terraces and retaining walls youll see in this collection can be found in nearly any suburban neighborhood. Many contemporary terrace gardens are also in urban areas, and use extensive container gardening to create these small gardens in the lack of a traditional planting bed.

The above terrace is an expansive garden with a small pond, waterfall, and small evergreen bushes lining the larger terraces.

We hope youll enjoy this unique collection and find inspiration for your own garden!

Find more backyard ideas in our definitive guide to backyards!

A contemporary home with terraced landscaping on either side of the stone stairs that lead up to the front door. The light colored stones are stacked neatly around the planting beds, making the hillside less dramatic.

A stone retaining wall that snakes around either side of a paved pathway. Ornamental trees, flowers, and draping vines fill in and around the sides of the two terraces.

A simple terrace created with wooden blocks, chicken wire, and large stones for a rustic look. The landscaping is simple and low maintenance. Source: Zillow DigsTM

Stacked landscaping stones are an easy and great way to keep grass out of your planting bed and add curb appeal to your landscaping. Any borders you create will stay in place.

Thin slate stones stacked create a natural-looking, simple barrier between the landscaping and the grass.

A more country, rustic retaining wall by the side of a paved pathway, creating a terrace up the large hillside. Moss grows on the old stones, marking this wall as well aged.

The stones used to create these terraces and retaining walls are speckled with small holes that give them the appearance of a kitchen sponge.

A retaining wall with two tiers of landscaping that follows a paved pathway.

A series of light stone retaining walls that help keep the sand dunes from eroding away and also provide a sturdy place for larger evergreens to grow.

A simple, curved retaining wall that forms a circular planter full of petunias.

A retaining wall of light stacked stone that is uniform in color and size. The ground above the stones is covered in a thick groundcover.

A hand-laid retaining wall made out of natural stone. Two terraces are filled with low maintenance landscaping. The terraces smooth out angle between the much higher house and the lawn.

A series of layered stone terraces between the highest and lowest levels of a split-level home. A ramp is overhead. Source: Zillow DigsTM

A simple retaining wall that creates a raised gardening plot filled with petunias, black-eyed susans, and other members of the daisy family.

Terraces of multiple heights surround this pool complex, creating a private oasis.

A new garden with several garden tiers and new growth. The stone retaining walls will keep the arrangements separate.

Beautifully fashioned retaining walls, each with a different plant in large groups.

A series of retaining walls surrounding a waterfall that runs into a small creek down the hill.

Lush landscaping with a small birdbath, looking glass, and uniformly stacked stones. A small set of stairs leads up to a pathway on the top terrace.

A retaining wall next to a stone courtyard in alternating red and gray stone.

A simple terrace garden with ornamental grasses and bushes.

A residential terrace garden along a winding stone path along the side of the home.

A look at the above terrace garden and path from the rear of the home.

Stone retaining walls running beside a packed dirt road.

A short retaining wall that creates dedicated planting beds easily distinguishable from the grass lawn.

A series of small concrete terraces create steps along this hillside. Soft, plush grasses make this spot perfect for sitting.

A retaining perimeter wall around the wooden backyard patio. The top tier runs into the surrounding woods.

27 Garden Trellis and Lattice Ideas (Wood & Metal)|50 Creative Container Garden Ideas (Illustrations)|30 Incredible Sundeck Designs and Patios by Top Designers Worldwide|65 Walkway Ideas & Designs (Brick, Flagstone & Wood)

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27 Backyard Retaining Wall Ideas and Terraced Gardens

Residential / Commercial

VERSA-LOK offers eight attractive segmental retaining wall systems equally suited for residential, commercial and public works applications: Standard, Accent, Cobble, Mosaic, Square Foot, Ultra, Nexus and VERSA-Green, a plantable retaining wall system that becomes a living part of your landscape.

Since 1987, VERSA-LOK has been creating Solid Solutions for architects and engineers with the industrys original solid, top-pinning segmental retaining wall system. Our low-absorption, high-strength, solid concrete units provide not only the long-lasting durability engineers expect, but also the limitless number of design options architects demand.

Create curves, corners, stairs, columns and freestanding walls using Standard, Cobble or Accent VERSA-LOK units, or combine the three to form the random-pattern Mosaic Retaining Wall System. VERSA-LOK wall units are available in the classic split-face texture at all locations and in the vintage Weathered texture at select locations. These products all work with VERSA-LOK cap units.

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Our original, most popular unit, the Standard unit is the backbone of VERSA-LOK retaining wall systems. The unit's solid construction and unique pinning system provide an endless array of design options, hardcore durability and the fastest, easiest installation available. Not only straight retaining walls, but also curves, corners, columns, stairs and freestanding walls are possible with the Standard unit, making it a universal favorite among homeowners, contractors and landscape architects and designers alike. This all-purpose retaining wall block also is available a Weathered texture option at selected dealers.

Create eye-catching designs by combining VERSA-LOK Standard, Cobble and Accent units to form the random-patterned Mosaic Retaining Wall System. Attractiveanddurable, the Mosaic system uses a four-unit panel (10" x 24")consisting of one Standard, one Cobble and two Accent unitsgiving each wall an interesting and visually arresting look and feel. Although they can create seemingly complex patterns, the simple four-unit Mosaic panels are just as easy to install as our Standard, Cobble or Accent Retaining Wall Systems.

About half the size of the VERSA-LOK Standard wall block, Cobble units are perfect for planters, small walls and countless garden-variety projects. Smaller and conveniently lighter than its big brother Standard unit, versatile Cobble wall units retain the same top-down pinning system, saving you time and installation costs.

A slimmed-down version of the Standard wall unit, Accent units measure 4 inches tall by 12 inches wide. They're lighter than Standard units, but engineered with the same high-strength, low-absorption concrete. Easily installed, Accent units draw minimal attention to the wall, saving the spotlight for pools, gardens, and other features of the surrounding landscape.

Cap units can put the finishing touch on your VERSA-LOK retaining wall. They're available in two stylesA and Band are 3-5/8" tall by 14" wide (at the face). Caps can be used with all types of designs. For straight walls, use both caps alternately. Outside curves require A caps only while inside curves use B caps.

Square Foot is a premium cored unit that covers a full square foot of wall face economically, making it a low-cost alternative for some commercial applications. Its trapezoidal shape and top-pinning system allow for variable bond construction, accurate alignment, tighter vertical joints and easy installation. Square Foots unique design enables a near-vertical setback, and its thick face affords greater durability than other cored systems.

The VERSA-LOK Ultra retaining wall system offers VERSA-LOK's renowned durability and stunning looks in a lighter weight unit that opens up a new world of design options, either on its own or in combination with other VERSA-LOK units. Its six-inch height makes it easy to integrate with Standard, Cobble, and Accent units.

When you need to retain a lot of ground economically, the VERSA-LOK Nexus retaining wall system can meet your projects design specs and budget and create a great-looking retaining wall. The top-stud design readily accommodates a variable bond, so you can create walls that have a more natural appearance.

The VERSA-LOK Harmony retaining wall system uses Standard and Cobble wall units to create designs limited only by your imagination. Combine the units in countless ways to create a variety of natural-looking designs. At half the width and the same height as Standard units, Cobble units can be set randomly among Standard units or the two types of unit can be set in a repeating ratio.

The new VERSA-GreenPlantable Wall System combines the durability and strength of a VERSA-LOK segmental retaining wall with the lush beauty of a hanging garden. Inside each unit is a 6"-deep plantable core for planting and a groove in the top to accommodate irrigation tubing. The result is a functional wall that becomes a living part of your landscape.

In addition to our line of traditional segmental retaining wall systems for residential and commercial applications, VERSA-LOK also produces Brute and Bronco, two products specially designed for select large-scale commercial or agency projects. Brute and Bronco are manufactured to the same industry-exceeding standards as our other products.

The massive size of VERSA-LOK Brute240 pounds and 1-1/3 square feet face areamakes it the ideal solid solution for unreinforced walls to 8 feet; limited-access sites; sites where extensive excavation isnt possible or practical; vertical retaining walls; walls subject to impact; or shoreline applications. Brute is installed mechanically in pairs using a special clamp attached to a backhoe or other lifting device and employs VERSA-LOKs top-pinning design for quick unit alignment and construction versatility. Brute is only offered in certain regionscontact your local VERSA-LOK dealer for availability.

When youve got a landscaping job that requires a colossal-size segmental retaining wall (SRW), call for Bronco. Weighing in at 4,500 pounds and displaying 14 square feet of face area, Bronco has the heft and coverage to tackle any job you can throw at it. The heavyweight system builds walls up to 10 feet tall without soil reinforcement, making it ideal for projects with excavation constraints. And with a unique four-panel, natural-stone appearance, Bronco is the most attractive random-pattern large-block SRW system available.

When youve got a project that requires a heavy-duty retaining wall, call for Bronco II, the new heavyweight segmental wall system from VERSA-LOK. Weighing in from 1,225 to 3,215 pounds and displaying 6 square feet of face area and a 3.2 batter, Bronco II has the heft and coverage to tackle any job. Alignment knobs molded into the top of units and channels molded into the bottom ensure correct near-vertical positioning and allow for tight joints with variable-bond construction.

The VERSA-Lifter makes it easier to lift and place units, especially on the base course. The two prongs on the lifter are placed into the holes in the VERSA-LOK unit. The action of lifting the handle secures the lifter to the unit and makes for easy, balanced lifting and placement. VERSA-Lifter are available from your local supplier.

VERSA-LOK Fabric is ideal for soil reinforcement of shorter walls. This geotextile is both cost-effective and easy to install. It is available in convenient, ready-to-use roll sizes.

Engineered for durability and long life, VERSA-Grid geogrid is a high-performance soil reinforcement composed of high-molecular-weight, woven polyester yarns with a polymeric coating. Properly designed VERSA-LOK walls with VERSA-Grid soil reinforcement can be constructed to heights of 50 feet or more.

A single-component, non-sag elastomer, VERSA-LOK Concrete Adhesive is designed for use in non-traffic bearing joints, including those where structural movement or stress is expected. Each VERSA-LOK Concrete Adhesive cartridge contains enough adhesive to cap approximately 14 lineal feet of wall.

VERSA-LOKs original, solid pinning system provides a mechanical interlock between retaining wall units and a mechanical connection to geogrid soil reinforcement.all Systems.

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Segmental Retaining Wall (SRW) Blocks for Landscaping ...

Retaining Wall Material Costs

The customer has the most control during material selection. While having a beautifully finished wall is of paramount importance, it is integral to weigh function equally with form. For example, using wood for the structure may not be the best choice if extreme moisture is a factor, as termites and wood rot may sharply decrease its lifespan. A good contractor can help choose the material with the best combination of looks and functionality, ensuring an aesthetically pleasing final product that lasts for years.

Consider that cinder block walls arent secured deep into the ground by footings. They are installed in trenches and, therefore, should not be built higher than 4 feet for stability purposes.

Modular concrete blocks are similar and provide many of the same benefits. The main difference is that modular blocks are designed in such a way that they interlock for easy, lego-like installation. The speed of installation beats that of many other materials. There are more style and color options, and homeowners can pay a little more to get close to the look of natural stone.

One of the most popular brands of modular concrete blocks is Versa-Lok. They use a pin and pin-hole interlocking system and have a broad range of styles available. With Versa-Lok, homeowners can achieve standard, weathered, cobbled, and mosaic. They are also fortified enough to build taller than with cinder blocks, at a similar material price.

Similar to cinder block, poured concrete is durable and resistant to deterioration. The pouring method makes for a solid piece of concrete which is stronger than cinder block, but much more expensive. The result of the process is a sleek, modern design.

Wooden retaining walls are a favorite for gardens because their natural appearance harmonizes with landscape surroundings. Wood materials are often cost-effective and easy to obtain, though there are several varieties which can raise your price point significantly.

The downside of using wood is that it is susceptible to rot and water damage. Drainage, waterproofing, and pest control solutions are key to the longevity of this material. With quality care, it can last beyond 20 years. As with cinder blocks, it is best not to build them taller than four feet.

Used railroad ties will have been chemically treated so it is important to find out which chemicals are present before you buy. If youre not sure about buying used materials for your project, there are a number of companies which manufacture new planks for building with the same visual appeal.

The lower cost per square foot of natural stone materials may be deceiving, as the labor rates associated with installing this material drive up your overall budget significantly. Natural stones like boulders and rocks are heavy and difficult to work with. Expect to pay a minimum of $25 per square foot for labor and materials. The hourly cost for building with dry stacking stones is $65/hr, compared to brick installation at only $15-$25/hr (see more on labor below).

This style is great in shifting environments, such as banks near the ocean. The structure can adapt and move with the soil as it shifts, rather than cracking or tumbling. This is because it is built using wire or wire mesh cages, which come at $30-$40 per cubic yard, and durable filler materials. Gabion retaining walls can be made with a variety of filler materials, from crushed concrete to stones or wood. Your cost will depend greatly on the type of filler you use. Otherwise, installation is relatively simple and affordable.

Metal, while it doesnt typically call to mind a natural landscape, can make for a long-lasting and efficient retaining wall. Common materials include Corten Steel, steel and aluminum. These materials have many benefits, including their water resistance, their proven longevity, and their strength--though steel, of course, is much stronger than aluminum. Most of them can be found in both corrugated and plate form, for your taste and aesthetic.

Using earth or chalk materials is a natural and sustainable choice, but your cost can vary greatly depending on the style and material used. Typically, compressed earth blocks and rammed earth walls are made with chalk, earth, lime or gravel and are fortified with materials like clay and sand.

Compressed earth blocks are different from rammed earth walls in the way that concrete blocks are different from poured concrete. Rammed earth is created using a framework and forms a large slab that costs around $23-$27 per square foot. Compressed earth blocks are compressed individually and can come as low as $3-$7 per square foot, or $0.50-$1.00 per block.

Both forms are strong and low-maintenance. The material is inherently vulnerable to water damage, however, and must be waterproofed in order to ensure longevity. Homeowners can opt to include reinforcements, such as rebar, and a typical earthen retaining wall will include footings or a concrete slab for added stability. The most significant price factor involves labor.

Installing railroad ties is often one of the easiest and most cost-effective choices. With material and labor, you are looking at $25-$30 per square foot. This is because they dont demand much extra material or many tools. In fact, they are a common DIY project for homeowners.

Interlocking blocks are convenient for installation, saving time, equipment, and material costs. Material and labor averages $15-$30 per square foot. Some homeowners find that they are able to construct these walls all on their own, but it would still be wise to seek the guidance of a landscape architect.

While the material estimate for rammed earth can be relatively low, labor rates can be significant. If you opt for the compressed earth blocks, the price for labor and materials will look more like that of concrete blocks at $15-$25 per square foot. With monolithic slabs of rammed earth, however, you could be looking at paying $30-$40 per square foot.

These types of retaining walls are constructed using concrete, timber or even plastic, The materials are arranged in such a way that they create cells, which are filled with stone for water passage. They do not require reinforcement, as they are a form of gravity wall which achieves stability through interlocking materials. The ease of installation, for Criblock materials, lowers labor costs.

Several different factors can drive up labor rates quickly. A wall of greater-than-average height can increase costs, and how easily the workers can access the project site will also impact the final labor quote. If a gate or fence must be taken apart or removed in order to bring materials to the site and perform the work, count on adding this time to the overall budget. In addition, labor may also be added if the dirt removed has to be disposed of somewhere other than the project property. Figure an average labor rate of $53 to $58 an hour, depending on your region.

Miscellaneous Costs

These prices include specific tools needed to perform certain work during construction or even additional materials to strengthen the wall itself. For example, soils with heavy clay content retain water much more than those low in clay. This extra water weight requires that some be constructed with additional materials, usually fabrics, that distribute the weight evenly to prevent failure. Reasonable miscellaneous costs run in the range of about a dollar per square foot.

A lack of soil testing can lead to detrimental missteps and extensive repairs. Footing that is too shallow and doesnt reach below the frost line will be susceptible to changes in the soil. An underestimation of pressure, from wet soil or weight, will make it susceptible to tilting or even collapsing. Poor construction and cheap materials make for a weak and vulnerable structure that may need to be replaced entirely.

Excavation and grading will play a large role in your cost if you need to completely replace the structure. If your current wall is made of poured concrete, for example, it is a lot more difficult to remove and will run you more in labor and equipment. The following are averages associated with each service necessary for replacement.

Pitfalls of Retaining Walls

Building a long-lasting retaining wall is vastly more complicated than simply piling up blocks and shoveling dirt. Moisture is its primary enemy, and if not properly mitigated, can lead to expensive failures. Cracks are also a common feature in walls that haven't been properly drained, due to the extra weight and temperature differences that come with moisture-soaked soils.

If it is going to be higher than average, professional help may be required. Some states require the use of an engineer during the design process if it exceeds a specific height. The overall height includes the portion that is buried in the dirt, known as the "key", which is vital to ensure the lower portion doesn't collapse and cause soil sliding. Be sure to check local building codes regarding vertical feet; if the intended wall requires hiring an engineer, count on your overall budget increasing.

Most projects don't deal with every factor that increases cost. On average, most only have two or three common factors which many contractors can easily work with.

Retaining walls can be beautiful and capable, and if done well, will last for several decades. However, with so many factors during design and construction that can lead to a poor outcome, take the time necessary to decide the size that will best suit your need, as well as which acceptable materials will last the longest. Using professional contractors and engineers as needed will ensure the perfect end result and years of reliable use from the retaining wall.

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2018 Retaining Wall Costs: Calculate Cost to Build + Block ...

Sure, retaining walls look like simple stacked stone, block, or timber. But in fact, they're carefully engineered systems that wage an ongoing battle with gravity. They restrain tons of saturated soil that would otherwise slump and slide away from a foundation or damage the surrounding landscape. These handsome barriers also make inviting spots to sit, and can increase usable yard space by terracing sloped properties, something that is increasingly important as flat home sites become ever more scarce in many regions.

Along with sloped landscapes where water runoff causes hillside erosion, ideal locations for a retaining wall include spots downhill from soil fault lines and where the downhill side of a foundation is losing supporting soil or its uphill side is under pressure from sliding soil.

If your property needs a retaining wall, or if the one you have is failing, review these descriptions of the four most common types: timber; interlocking blocks; stacked stone, brick or block; and concrete.

Common ProblemsAlthough retaining walls are simple structures, a casual check around your neighborhood will reveal lots of existing walls that are bulging, cracked, or leaning. That's because most residential retaining walls have poor drainage, and many aren't built to handle the hillside they're supposed to hold back.

Even small retaining walls have to contain enormous loads. A 4-foot-high, 15-foot-long wall could be holding back as much as 20 tons of saturated soil. Double the wall height to 8 feet, and you would need a wall that's eight times stronger to do the same job. With forces like these in play, you should limit your retaining wall efforts to walls under 4 feet tall (3 feet for mortarless stone). If you need a taller wall, consider step-terracing the lot with two walls half as big, or call in a landscape architect or structural engineer for the design work (have the architect or engineer inspect the site thoroughly) and experienced builders for the installation.

If you have your retaining wall built, figure about $15 per square face foot for a timber wall, $20 for an interlocking-block system or poured concrete, and $25 for a natural-stone wall. Preparing a troublesome siteone that includes clay soil or a natural spring, for examplecan raise costs substantially. Add 10 percent or so if you hire a landscape architect or engineer. But shop around; some landscape firms do the design work for free if they do the installation.

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Engineering a Retaining Wall | This Old House

How soil pushes (and how to build a retaining wall that pushes back)

When you contemplatehow to build aretaining wall a retain wall design, you may imagine how firm and solid itll appear from the front, or how great the new garden will look above it. But unless you give serious thought to what goes on behind and below the wall, it may not look good for long. A poorly built wall can lean, separate, even toppleand its out there in plain sight where all your neighbors can point and snicker. You dont want that!

Lots of people think a retaining wall needs to hold back all 6 gazillion tons of soil in the yard behind it. It doesnt. It only needs to retain a wedge of soil, or elongated wedge of soil, similar to that shown in Fig. A. In simple terms (our apologies to all you soil engineers out there): Undisturbed soilsoil that has lain untouched and naturally compacted for thousands of yearshas a maximum slope beyond which it wont hang together on its own. This slope is called the failure plane. If left alone, the soil behind the failure plane will stay put on its own. But the soil in front of the failure planethe natural soil or the fill youre going to addwants to slide down the failure plane.

Gravity, along with the slope, directs most of the weight and pressure of the fill toward the lower part of the retaining wall. Since soil weighs a beefy 100-plus lbs. per cu. ft., you need some pretty heavy materiallarge retaining wall blocks, boulders, timbers or poured concreteto counteract the pressure. Just as important, it needs to be installed the right way. Here are three key principles in building any solid retaining wall:

A retaining wall needs to retain all the material that fills the space between itself and the failure planethe steepest angle at which existing soil can hold itself together before caving in.

Water can weaken retaining walls by washing out the base material that supports the wall (Fig. E). But far more frequently, it causes problems by building up behind the wall, saturating the soil and applying incredible pressure. Thats when walls start leaning, bulging and toppling. Well built walls are constructed and graded to prevent water from getting behind the wall and to provide a speedy exit route for water that inevitably weasels its way in.

Take a look at the well-drained wall in Fig. D. The sod and topsoil are almost even with the top block, so surface water flows over the top rather than puddling behind. Just below that is 8 to 12 in. of packed impervious soil to help prevent water from seeping behind the wall. The gravel below that soil gives water that does enter a fast route to the drain tile. And the perforated drain tile collects the water and directs it away from the base of the wall, escorting it out through its open ends. Theres nothing to prevent water from seeping out between the faces of the blocks, either; that helps with the drainage too. The wall even has porous filter fabric to prevent soil from clogging up the gravel. What youre looking at is a well-drained wall that will last a long time.

Now look at the poorly drained wall in Fig. E. Theres a dip in the lawn that collects water near the top of the wall. Theres no impervious soil, so the water heads south, slowly waterlogging and increasing the weight of the soil packed behind the wall. The homeowner put plastic against the back of the wall to prevent soil from oozing out between the cracksbut its also holding water in. Yikes! Theres no drain tile at the bottomthe trapped water can soak, soften and erode the base material. Not only that, an excavated trench that extends below the base lets water soak into the base material and weaken it. Youve got a retaining wall that has to hold back tons and tons of water and saturated soiland when that water freezes and expands in the winter, matters get even worse.

A strong retaining wall design features well-compacted base material, compacted material in front of the wall to prevent kick-out, and stepped-back materials.

A wall that has an uneven base, no compacted material in front of it and no step-back to the materials will eventually fail.

Even if you have only a small wedge of soil to retain like that shown in Fig. A, compaction is important. If your failure plane is farther back so your wall needs to retain more fill, weight and pressure, then compaction and a reinforcing grid become critical. These two things help increase internal friction and direct the pressure of the fill you add downward (Fig. F), rather than at an angle pushing against the wall. Good compaction doesnt mean dumping a couple of feet of fill behind the wall, then jumping up and down on it in your work boots.

Nope, good compaction means adding 3 or 4 in. of material, compacting it with a heavy, noisy vibrating plate tamper from your friendly neighborhood rental yard, then repeating these steps over and over. Your landscape supplier or block manufacturer (if youre using modular blocks) can tell you whether you need to install reinforcing grid, and at what intervals. The taller the wall, the more likely youll need reinforcing grid.

When building a retaining wall, never backfill with, or compact, topsoil; it will break down and settle, creating a water-welcoming trench behind your wall. Use sandy or gravelly materials, which compact much better. And always make certain you dont become overzealous and compact your wall outward.

From top to bottom, a well-built wall either prevents water from getting behind the wall or ushers it away quickly when it does.

Water trapped behind a wall pushes against it and increases the weight of the soil, which also pushes against it.

By themselves, landscape timbers and a railroad tie retaining wall lack the weight to hold back soil. To make these walls strong, you need to add deadmen, anchors that lock the wall into the soil behind them (Fig. G). The same pressure thats pushing against the wall pushes down on the deadmen to keep them (and therefore the wall) in place. The principles of stepping back, installing good drainage and compacting also apply to timber walls.

Walls of any material that are taller than 4 ft. play by the same rulesits just that the wedge of soil is too big and heavy to be held in place by the weight of the materials alone. Some communities now require building permits and construction details for walls exceeding 4 ft. in height. We think thats a good idea too. Many modular block manufacturers can supply printed sheets of structural information.

For tall slopes, a series of tiered walls is a good substitute for a single tall wall. But an upper tier can apply pressure to a lower tier unless its spaced the proper distanceyou know, behind the failure plane. The rule of thumb is to set back the upper wall twice the height of the lower wall.

Compacting backfill in 3- to 4-in. layers and installing a reinforcement grid directs pressure downward, rather than against the wall.

A deadman helps anchor a timber wall in place when building a retaining wall. The same pressure thats pushing against the wall is pushing and holding the deadmanand therefore the wallin place.

Have the necessary tools for this DIY how to build a retaining wall project lined up before you startyoull save time and frustration.

Avoid last-minute shopping trips by having all your materials ready ahead of time for this how to build a retaining wall project. Heres a list.

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How to Build a Retaining Wall Stronger | Family Handyman

1. Incorporate the Wall Into Your Lifestyle

Retaining walls are usually thought of as utilitarian and for merely holding back soil. But you can use them to create beautiful outdoor living spaces and incorporate multi-use spaces.

Retaining walls don't have to be perfectly straight. Add a curve to dress up a boring straight wall and to add a little more texture to your landscape. You can use a garden hose or large rope to set the layout of the curve, then use a shovel to cut through the soil to follow the curve.

Smaller retaining walls, such as those less than four feet, can be easily planned and created without worrying too much about structure. Larger walls above that height may need an engineer's touch. Also be sure to check with local codes before starting one more than four feet tall.

From a lower grade, you'll need to gradually step up the retaining wall to reach a greater slope. Do this in increments and plan for a slight offset for each course change.

Besides offering a consistent look, manufactured blocks and stones for retaining walls offer structural integrity and an even base with which to work. There is little guesswork in installing, plus you'll have less work to do making sure each course is level. Be sure to color match and space out uneven colored stones and blocks for a better look.

Dig out your base several inches below grade and tamp/compact it to level. Add any filler, such as gravel, before adding your first stones or blocks. Remember, the base sets the tone for the entire wall, so spend a lot of time in preparing this key component.

A retaining wall that has a slope dropping to it will need additional drainage at the base. Add gravel and a fabric-covered drainage pipe at the base. The fabric will help prevent clogging of the pipe — a key feature as you will not want to dig out the pipe later to unclog it.

For each course of stones and blocks, be sure to check for level. This will help maintain a sturdy and balanced wall, plus you'll keep an even and consistent look.

Backfilling as you go adds support in success layers, so as you add a new course of blocks or stones, backfill to match this level. Be sure to tamp in/compact the soil as well, so you don't have as much settling later.

Add cap blocks to the top row of a block or stone retaining wall. You can add a layer of masonry adhesive to hold them in place, then back fill. Or you can backfill as you go, then add the cap. Either way, it provides a nice finished look, much like edging added to a paver patio.

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10 Things You Must Know About Retaining Walls | DIY

Our experts prefer crushed stone for the base rather than naturally occurring gravel dug from a pit. Crushed stone is a little more expensive. However, it provides better drainage, and because of the sharper angles on the stone, it requires less compacting, and once its compacted, it stays that way.

Joe and Jake have found that crushed stone sized between 1/2 in. and 3/4 in. is best suited to handle the heaving forces created by the harsh freeze/thaw cycles here in Minnesota. Avoid rounded stones like pea gravel or river rock; they dont form strong interlocking bonds like angular stone.

Leave the stone no more than 1/2 in. higher than you want the final height to be, and then make a couple passes with a hand tamper or plate compactor. Youll notice the stone is almost 100 percent compacted as soon as its laid in the trench. The same type of stone will be used for backfilling, which also eliminates the need for hauling in multiple materials.

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Build a Long-Lasting Block Retaining Wall | Family Handyman