Virginia's Segmental Wall and Hardscape Specialists
 

This page contains the definitions of some of the words or phrases used in the construction of segmental retaining walls (SRW).

 

Aggregate

Inert material as in sand, gravel or slag.

Backfill

Material used to replace that which was excavated behind the wall.  It may consist of soil or "clean" aggregate.  Drainage concerns and wall type will determine the type and quantity of backfill material.

Base

The excavated area of the ground in which base material is placed, compacted and leveled on which the base course of the retaining wall block is placed.  Syn: Leveling Pad

Base Course

The first row of blocks placed on top of the leveling pad where the top of the block is at or below grade.  Some walls may have more than one course of blocks below grade

Base Material

Usually 3/4" aggregate with fines used to create a level area for the first base course.

Batter

The angle, measured in degrees, created from the setback of a segmental retaining wall block.  It is the angle measured using a plumb line from the toe to the top of the wall and the face of the wall.

Bench Cut

A horizontal cut across a slope.

Beveled Face

The laterally exposed areas of the retaining wall block are angled and not flat.

Column

Vertical pillar at the end, corner or middle portion of the retaining wall.  Can be used independently also.  Adds support to the wall.

Compaction

Compressing the material used in the base and backfill areas of a retaining wall.  Compaction is important in wall construction, with each course being backfilled and compacted to a 95% proctor.

Course

A horizontal layer or row of retaining wall blocks.

Crest Slope

The angle of soil above the wall.

Efflorescence

A whitish substance that can naturally occur on all concrete products.  The condition will usually disappear over time with weathering.  It comes from lime deposits within the concrete.

Face of Wall

See Wall Face

Fines

Smaller particles of aggregate.

Foundation Soil

The supporting material for the leveling pad (base) of a retaining wall.

Free Standing Wall

One which does not retain anything.  It is double-sided.  For aesthetic value.

Geogrid

A polypropylene or polyethylene material formed in a grid-like pattern used for soil reinforcement, synthetically made.

Grade

Ground level.

Gravity Wall

A segmental retaining wall that uses the setback and weight of the block to resist the soil pressures.  Geosynthetic reinforcement is not required on a gravity wall.

Leveling Pad

The excavated area of the ground in which base material is placed, compacted and leveled on which the base course of the retaining wall block is placed.  Syn: Base

Overturning

External lateral pressure on a retaining wall in which the soil mass rotates at the base of the wall creating an external stability failure.

Permeable Soil

Soil that allows water to pass through at an appreciable rate or unrestricted.

Proctor

The determination process for the moisture-density relationship in compacted soils.  Generally 95% is the goal.

Slope

Angle of soil, usually expressed in a ratio such as 3:1 (3 feet horizontal and 1 foot vertical).  See also Toe Slope and Crest Slope

Straight Face

The exposed surface of the retaining wall block is flat and not angled or beveled.

Surcharge

A force or pressure exerted on top of a segmental retaining wall. (SRW).  May consist of a road, parking lot, building foundation or machinery/equipment.

Swale

A ditch or depression in the soil at the top of the retaining wall used to divert water to another location away from the wall.

Toe Slope

The angle of soil in front of and at the base of the wall.

Wall Face

The exposed area of a retaining wall with a degree of batter.