There are several ways to build a retaining walls just as there are several materials which can be used. Retaining walls are one of the most integral parts of landscaping, both residentially and commercially. Many homes and buildings are built no hilly or uneven ground (especially in New England). When a building is on a slope it is extremely important to ensure the solidity of the rock and soil around the base of the building. In addition soil can shift overtime throughout the landscape which makes retaining walls an important structure to maintain the natural beauty and shape of the land.
Commercial Retaining Walls
In a future blog will we cover the residential retaining walls, however the general concept and engineering is the same. Retaining walls are primarily used to hold (or retain) soil in its proper position. However, they can add a nice aesthetic appeal as well. The main difference between residential and commercial retaining walls is commercial walls often need to be sturdier and therefore more elements have to be added to increase strength and reinforce the wall. A small retaining wall for something like a flower bed may only require a few boards or stones. Large retaining walls which help support soil around the foundations of buildings or parking lots require much more stability.
Gravity Retaining Walls
One of the most common types of commercial retaining walls is the gravity wall. The name “gravity” is used because the wall relies on its own weight to stand. When a retaining wall is built, one of the keys is to determine the “wedge.” This is the section of soil which would slide away leaving the natural slope (or fail plane) remaining. This “wedge” section of soil is essentially what the retaining wall is there for. The strength of the gravity wall is determined based on the wedge it is responsible for retaining. Gravity walls are generally only about 6 feet tall as they need extra support once the wedge has increased beyond that height.
Reinforced Retaining Walls
The second common type of retaining wall is the reinforced retaining wall. Interestingly, the Great Wall of China is essentially is a double sided retaining wall. Reinforced retaining walls are used when a height of greater than 6 feet are required. In order increase the strength of the wall a flexible, synthetic mesh known as a geogrid is added to the wall. These walls are manufactured to help increase slope stabilization and assist with earth retention. Geogrids come available in many size and strengths and are made of a variety of materials. In some cases it is best to use another type of reinforcement such as steel rods, earth anchors, rock bolts, etc.
Of course, retaining walls are primarily functional structures. This means they are not normally installed for their aesthetics, however they can be an attractive section of your landscape. You basic shape will be determined by the reason for the wall, but you should have some influence over the color, texture and other aspects which will enhance its beauty. Other elements such as surcharges (support for added weight above the wall like a parking lot or swimming pool), proper drainage, grading, slope, and set back ( the amount the wall leans into the hill) are all important to determine so that you have a durable and satisfactory wall for years to come.
When building your retaining wall, it’s important to make sure it is done correctly, here at New England Enterprises in Marlborough, MA, we’re experts in building walls. Whether you need a gravity wall, a reinforced wall, or a customized wall, we’ve got the tools and experience to build what you are looking for, on budget. Contact us to learn more and get a consultation on the job, including a detailed plan on your project and an estimation of cost.