The Anatomy of a Retaining Wall

Written by: Danelle DeMartini

A retaining wall is a structure that holds or retains soil behind it. There are many types of materials that can be used to create retaining walls like concrete blocks, poured concrete, treated timbers, rocks or boulders. Some are easy to use, others have a shorter life span, but all can retain soil.

SRW’s (Segmental Retaining Walls) like the Allan Block products, offer concrete masonry blocks that are modular and interlocking for ease of use. Simply stack the mortarless blocks together using our installation information, and create a maintenance-free retaining wall that will add usable land, fix a grading or slope issue, and solve many other site problems. These SRW’s use similar construction techniques as found in the mortarless construction of the Great Wall of China and the Pyramids of Egypt and will stand the test of time. 

The basic parts of a segmental retaining wall, or modular concrete block wall consist of:

Retained Soil:

The area of soil behind a retaining wall that is contained by the wall structure

Infill Soil:

The soil used to backfill behind the wall rock in the reinforced zone. These soils need to be identified and approved by a qualified engineer before they can be used. A granular type of material is best. 

Reinforcement grid:

A manufactured high strength reinforcement grid material that comes in rolls of various sizes and strengths.

Allan Block (segmental retaining wall block - SRW):

Hollow core segmental retaining wall block (SRW) used as the face of the retained soil mass. 

Wall Rock:

Compactible aggregate ranging in size from 0.25 in to 1.5 in. (6 mm to 38 mm) with no more than 10% fines. Used for base material, within block cores and behind the block. 

Drain Pipe:

Used to direct incidental water that makes its way in behind the reinforced mass, and vents it to daylight by creating a channel for the water to flow out from.

Once you build a wall with an SRW – you can be sure it is built to last. For more information on  segmental retaining walls and construction techniques, visit our website at allanblock.com.