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- Shield Civil Engineering Spotlight: Segmental Block Retaining Walls
Retaining walls are complex structures that serve a variety of purposes. From erosion control to soil containment, retaining walls come in all shapes and sizes and can either be gravity-sustained or geogrid-reinforced in nature.
Shield Engineering works regularly with developers and municipalities on retaining wall projects. We often use segmental retaining walls for their durability, height capabilities, and dimensional tolerances. Today, we’re spotlighting the benefits and competencies of these common structures.
What are Segmental Retaining Walls?
Segmental retaining walls are retaining walls used to support vertical grade changes that are made of modular blocks. They can be implemented as gravity retaining walls or as reinforced soil retaining walls, depending on the application. The benefits of segmental retaining walls are myriad, including ultimate customizability (create curves, steps, and columns) as well as unparalleled durability.
This type of retaining wall typically consists of a facing system and a lateral tieback system. The most common materials used for segmental retaining walls are interlocking concrete blocks or wood, although concrete is highly-durable and allows for more aesthetic creativity.
Why Use Segmental Retaining Walls?
When are segmental retaining walls preferential to traditional walls? Because they can be constructed quickly, these kinds of retaining walls are used for both residential and commercial applications. Highly-versatile, segmental walls can be formed into shapes and curves that traditional walls simply cannot. They provide for an easy solution to grade changes and require no concrete footings.
Segmental walls are actually suitable for extremely high gradings. In cases where the weight of the modular blocks will not adequately support the soil, horizontal layers of geosynthetic supports can be layered behind a wall, reinforcing the soil. It is possible to build segmental retaining walls at heights of 20, 30, and even 40 feet or more.
Constructing Segmental Retaining Walls
Once the underlying landscape has been thoroughly evaluated, an engineer typically creates a back fill drainage plan before installing any type of retaining wall. A leveling pad forms the base of any modular retaining wall, upon which blocks are stacked. Segmental retaining walls do not require mortar because they are designed to be somewhat flexible. Though completely structurally stable, these walls can tolerate slight earth movement without sustaining serious damage.
In most states, retaining walls over four feet must employ the assistance of professional engineers like the experts at Shield Engineering. Retaining wall design is a complicated process that factors in everything from groundwater conditions to soil characteristics, utilizing a deep understanding of lateral earth pressure. Segmental retaining walls are load-bearing structures first, landscaping tools second.
Shield Engineering has years of experience navigating the complexities of retaining walls for public works, commercial developments, infrastructure projects, and more. Contact our team of knowledgeable engineers today to find out how we can be your project’s one-stop-shop.