Backfill
Soil
placed in front of and behind base course units. Also soil placed
behind drainage aggregate. All backfill should be well compacted.
Loose backfill will add pressure on walls, collect water, cause
settlement and will not anchor soil reinforcement materials properly.
Backfill that is behind a wall containing soil reinforcement is
often referred to as reinforced soil.
Base
Course
The
base course is the first layer of VERSA-LOK® units placed on
the leveling pad. Extra care should be taken to ensure that all
base course units are level front to back, side to side, and with
adjacent units. Unevenness in the base course becomes magnified
throughout succeeding courses and cannot be easily corrected.
Bond
The
arrangement or pattern of units from course to course. A unit that
is centered over the joint created by the adjacent lowercourse units
is placed on "1/2 bond." VERSA-LOK's unique pinning system permits
variable-bond construction and allows units to fit close to each
other while interlocking correctly. In general, VERSA-LOK units
should be installed on 1/4 to 3/4 bond — where units overlap
vertical joints of adjacent lower course units by at least four
inches.
Compaction
Applying
mechanical force to soils so they are no longer compressible. It
is important to compact foundation and backfill soils to prevent
future wall movement. Compaction is often accomplished using a hand
tamper or a vibratory-plate compactor (available at most rental
stores).
Course
A
horizontal layer of retaining wall units.
Drain
Pipe
Typically, a four-inch perforated pipe placed behind the wall
at the base of the drainage aggregate. The drain pipe helps to direct
large amounts of water from behind the wall to areas where it can
accumulate safely away from the wall.
Drainage
Aggregate
Clear,
free-draining, angular gravel placed directly behind retaining wall
units to expedite drainage. Drainage aggregate should not contain
fine particles that could impede water flow.
Embedment
VERSA-LOK segmental retaining walls should have at least one-tenth
of exposed wall height embedded below grade. For example, a four
foot wall should have approximately five inches of the base course
buried below grade. Embedment provides enhanced wall stability and
long-term protection for leveling pads. Embedment should be increased
for special conditions such as slope at wall base, soft foundation
soils, and shoreline applications.
Grade
The ground level, or ground elevation.
Gravity
Wall
A retaining wall without soil reinforcement where unit weight
alone provides resistance to earth pressures. Gravity walls are
generally less than four feet in height and do not support slopes
or other loads above the walls.
Impervious
Fill
Backfill placed above and below the drainage aggregate. Impervious
fill helps to prevent large amounts of water from running down behind
the wall or getting to the leveling pad. Generally, compacted fine
grained soil is used as impervious fill.
Leveling
Pad
The
base on which a wall is constructed. Leveling pads consist of well-compacted
crushed stone, gravel, or coarse sand. The most commonly used material
for leveling pads is that which is used locally as road base aggregate.
Load
Weight or pressure placed on a retaining wall — usually
from the back or top. Nearby slopes, driveways, buildings, and tiered
walls all represent potential loads on retaining walls. Designs
for retaining walls that support loads should be reviewed by a qualified,
licensed professional engineer.
Saw
Cuts
Saw
cuts are made to modify VERSA-LOK units when smaller pieces are
needed. Saw cutting creates a smooth, straight surface to meet cleanly
with an adjacent unit. Saw cuts are generally made using a gas-powered
cut-off saw equipped with a diamond blade -- available at most rental
stores.
Setback
The
distance that each course is aligned behind the preceding (lower)
course. Each course is set back 3/4 inch from the front of the course
beneath it. This arrangement causes walls to cant back into retained
soil. Canted walls are structurally more stable than vertical walls
because gravitational forces "pull" walls into retained soil.
Soil-Reinforced
Wall
A retaining wall that incorporates horizontal layers of soil
reinforcement material behind the wall. Soil reinforcement combines
with soil to create structures that are strong and massive enough
to support large loads. Soil-reinforced walls generally require
a design by a qualified, licensed professional engineer (P.E.).
Soil
Reinforcement
High-strength, polymer geosynthetic material, such as fabric
or geogrid, that is buried in horizontal layers behind soil-reinforced
retaining walls.
Split
Splits
are made to modify VERSA-LOK units — most commonly to create
corner units. Splitting creates attractive, textured surfaces identical
in appearance to front faces of units. VERSA-LOK units can be easily
split using a hammer and masonry chisel or mechanical splitter.
This capability allows the user to create a wide variety of corners.
Split-face
The attractive, textured design on the front of non-weathered
VERSA-LOK units. VERSA-LOK units are manufactured in pairs connected
at their faces. They are then split apart, creating this appearance.
Tiered
Walls
Two
or more stacked walls with each upper wall set back from the underlying
wall. Tiered walls can be attractive alternatives to single tall
walls and can provide areas for plantings. To prevent an upper wall
from placing a load on a lower wall, the upper wall must be built
behind the lower wall a distance of at least twice the height of
the lower wall. Tiered wall designs should be reviewed by a qualified,
licensed professional engineer.
VERSA-Lifter®
The
VERSA-Lifter speeds installation of VERSA-LOK retaining walls by
making it easier to lift and place units --— especially on
the base course. The two prongs of the lifter are inserted into
pin 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-LOK®
Adhesive
VERSA-LOK
Adhesive is specially formulated to bond VERSA-LOK Cap Units to
the top of walls. This adhesive remains flexible to accommodate
the minor wall movement that may occur during freeze/thaw cycles.
VERSA-LOK®
Cap Units
VERSA-LOK
cap units are used to attractively finish the top of VERSA-LOK retaining
walls. Cap units come in two styles: A caps and B caps. Both cap
styles are 14 inches wide at the front, but A caps taper to 12 inches
wide at the rear and B caps increase in width to 16 inches at the
rear. To cap straight walls, alternate A caps and B caps. Use A
caps to finish walls with outside curves and B caps to finish walls
with inside curves. Front faces of cap units may be placed flush,
set back, or slightly overhanging (recommended) the face of the
uppermost course of VERSA-LOK Standard units.
VERSA-LOK®
Retaining Wall Units
Premium
retaining wall units offering easy installation, unmatched design
flexibility and unsurpassed durability. Units are installed without
mortar or concrete footings. An unlimited variety of curves, corners,
and steps can be constructed using only standard units. These environmentally
safe, solid concrete units provide a lifetime of virtually maintenance
free performance.
VERSA-LOK®
Weathered™ Retaining Wall Systems
VERSA-LOK Weathered units have rough, worn, rounded corners and
their faces are jagged and rocky. Of course, VERSA-LOK Weathered
units possess the same solid, pinned characteristics as all other
VERSA-LOK Retaining Wall Systems.
