Precast retaining walls

The design of our retaining walls is helping our customers to achieve time and resource savings of up to 20%.

Our Quicklift system means product can be lifted from delivery vehicle to final position using a standard lifting hook and with no need to work at height, while our joint profiles and corner details ensure quick and accurate alignment for faster installation times. We can also cast walls with a preformed finished for an aesthetically pleasing appearance.

Engineering and design

With customers ranging from the nuclear industry through to waste recycling, product performance requirements vary greatly.

Our team of engineers and designers can advise on all aspects of a project, from outline design through to final value engineering.


Quality assurance

From initial design through to onsite logistics, all aspects of the Bison Precast operation meet the most exacting quality standards. These are maintained by our own in-house Quality Inspectors, and audited by external certification bodies. Our precast facilities meet the requirements of ISO 9001, ISO 14001, BES 6001 and ISO 18001. All units are designed in accordance with Eurocodes and CE certified to BS EN 15258. A range of standard retaining walls is available from stock in seven different heights. Each unit is designed to be loaded from either side and can retain material level with the top of the wall, including a surcharge or a sloping backfill from the top of the unit without any surcharge. The walls rely on holding down bolts to resist overturning moments.


Standard of bespoke retaining walls

The standard range is available from stock, however, bespoke units offering variation in height, width, loading and accommodation of weep-holes or pipe openings can be provided.


Finishes & textures

Using state-of-the-art formliner technology, Bison Precast retaining walls, or bespoke precast items, can be cast with a preformed finish to the outside face.

ROUGH & TEXTURED FINISHES

Marne

Red River

Lausitz

STONE & ROCK FINISHES:

Mosel

Cheyanne

Romanche

BRICK & MASONRY FINISHES:

Brabant

La-reunion

Mayenne

RIB & WAVE FINISHES:

Amazonas

Amur

Fulda

ABSTRACT & WOOD FINISHES:

Champagne

Rugen

Spree

Hundreds of design options

We have over 200 designs to choose from and are happy to work with bespoke designs.

QUICKLIFT HANDLING GUIDE

The Bison Precast QuickLift system has been developed to ensure that no additional lifting equipment is needed other than conventional chains and hooks for the three lifting points. Unlike many other systems, there are no hidden costs for expensive lifting gear. Using a standard lifting hook attachment, a handler can complete a lift from wagon to final position with minimal secondary operations, increasing efficiency compared with alternative solutions by some 20%.


QUICKLIFT GUIDE 1

The walling system is delivered on a flat-bed wagon, nestled for maximum efficiency.


QUICKLIFT GUIDE 2

The Bison Precast walling system can be lifted off the wagon using either the three-point QuickLift system or traditional forklift method. Note: Ensure that the lifting/handling equipment is of an appropriate capacity to lift the units. For individual unit weights, please see unit specification. Lifting units with the three-point QuickLift system allows the units to be easily manoeuvred and rotated 180 degrees, thus enabling units to be placed directly adjacent to their final position.

Note: when determining the appropriate lifting/handling equipment, the radial dimension required to rotate the unit must be considered and chains set to a max angle of 65 degrees.

A Banksman should be used at all times to ensure units are safely spotted and manoeuvred.


QUICKLIFT GUIDE 3

<p>Once unit is in position adjacent to its final location, the lifter to the toe should be removed and the chains to the two main wall lifters shortened and secured to equal lengths to ensure a level and safe lift. The unit can then be lifted slowly, balancing the weight on the back of the heel.</p>

Note: if lifting off a hard surface then a block or mat should be used to protect from damage. As the unit is lifted, the vehicle should move forward slowly ensuring that the lifting chains are vertical at all times. Once the unit is upright, the third lifter can be re-attached to provide additional stability and manoeuvrability, allowing the units to be lifted clear of the ground into final position.


QUICKLIFT GUIDE 4

The wall can then be easily located into its final position. When positioning adjacent to another unit the male connection joint of the suspended unit should be inserted into the female then lowered slowly into position ensuring the units remain interlocked.

The Bison Precast Quicklift System – No hidden costs for expensive lifting gear

Unlike many other systems, we have no hidden costs for expensive lifting gear, or for the fitting of lifting attachments. Using a standard lifting hook, a telehandler can complete a lift from delivery vehicle to final position with minimal secondary operations, increasing efficiency against alternative solutions by some 20%.

In addition, all lifting positions are located within working-height zones, eliminating the need to work at height.

Joint profiles and corner details

All standard units come with a unique interlocking detail that enables faster installation times through accurate and fast alignment. This also ensures a strong and reliable connection detail that can be sealed with an appropriate product/material.

A range of economical corner details is also available.

Finishes

Using state-of-the-art formliner technology, the retaining wall unit can be cast with a preformed finish to provide an aesthetically pleasing appearance.

Standard range

Our range of standard precast retaining walls has been developed to offer the most economical solution in terms of transports costs, installation plant required, and installation times.


1m wall technical details

Height: 1000mm
Width: 1000mm
Depth: 500mm
Weight: 450kg
Embedment: 150mm

Ancillary items

Loose items schedule: per 1.00m unit
2 x M16 (Grade8.8) Galv Althread x 340lg
2 x M16 Galv Nuts
2 x 100 x 100 x 8thk Galv Plate washer (Ref: PW4)
Grouted in using C32/40 non-shrink grout


CORNER UNIT

We offer a range of economical corner details.


INTERLOCKING JOINT

Our standard units come with a unique interlocking detail that enables faster installation times through accurate and fast alignment. This detail ensures a strong and reliable connection that can be made waterproof with an appropriate sealing solution.

Note: all units will be supplied with a male/female connection detail as standard, however we are happy to provide a traditional flat joint detail to one or both ends if required.



Technical information – storage material densities

Table 1 Material
Medium dense sand Loose sand & gravel Grain Woodchip Sewage waste Rolled silage Paper waste Composted
green waste
PFA
Density (kN/m3) 18 16 8 8 11 4+72x
(see note 1)
6 5 10

Standard concrete specification

The concrete is produced in accordance with BS8500 to meet an exposure condition of XD2 with an intended life of 50 years.

Compressive strength class C40/50
Maximum water/cement ratio 0.5
Minimum cement/combination content 380 kg/m3
Allowable cement/combinations types CEMI
Maximum arregate size 20mm
Aggregates Freeze thaw resisting
Chloride content class Cl 0,40

Design scope / philosophy

The reinforced concrete precast retaining wall unit has been designed in accordance with the latest set of Eurocodes.

Storage capacity

Units are designed to be loaded from either side with the following conditions: retained material level with the top of the wall and with an applied surcharge of 10kN/m² or a sloping backfill with a maximum angle of 35º without an imposed surcharge. The retained material will be assumed to be granular and drained with a specific maximum moist density of 18kN/m³. For more information on specific material densities see table 1.

Steel grades

All steel to be grade S275 UNO. All anchor bolts to be min grade 4.6 UNO. See detailed bolt calculations.

Holding down bolts

Threaded rod anchor bars in grade 4.6 are used to anchor the base of the retaining wall into the cast-in-situ concrete base (by others). The length of the embedment will vary between units and loading; for minimum embedment depths into the in-situ base, please refer to relevant technical data sheets in downloads section. The rod is placed in the in-situ base through the preformed holes within the base of the precast wall unit and secured with min, 40N/mm² strength resin/non-shrink grout.

Exposure conditions

Due to a nominal cover of 45mm (including Δc of 5mm) and the mix design used, the standard range of retaining walls meet an exposure condition of XD2 with an intended working life of 50 years. Other exposure conditions can be designed for. Please contact Bison Precast for further details. The limiting crack width will be taken as 0.3mm.

Foundation type

Assumed to be uncracked, mass/reinforced concrete base of minimum strength 25N/mm2. This is to be designed by others to resist the overturning and sliding forces exerted by the retaining wall unit and to consider the allowable ground bearing pressure to the relevant site.

Overall stability

The primary job of the unit is to retain the material behind it. To do this, the stem and the base are designed to withstand the applied forces. To resist overturning and sliding with a factor of safety of 2 for overturning and 1.5 for sliding respectively, the units require anchoring into a mass or reinforced in-situ concrete base. The grouted, threaded rod should be post-fixed into the suitable base below and secured with a washer plate on top of the unit to increase the bearing capacity onto the base slab and prevent punching shear of the bolt head through the unit. The resistance of the anchors into the base must be checked by others. The overall ground bearing pressure must be checked by others and considered when designing the in-situ support base.

Reinforcement notes

All reinforcement to be high yield with a yield strength of 500N/mm². All reinforcement to be Type 2 deformed bars including any specified mesh. Minimum lap length to be 40 x smallest lapped bar diameter.


LOADING OPTIONS

Loading option 1

  • Backfill positioned over base of unit
  • Level backfill
  • 10kN/m² surcharge
  • Drainage assumed to rear of wall system

Loading option 2

  • Backfill positioned over base of unit
  • Sloped backfill at 35°
  • No surcharge
  • Drainage assumed to rear of wall system

Storage estimator

Use this tool to estimate the theoretical maximum storage capacity of our retaining walls when using for bulk storage purposes. The figure will be based upon assumed densities of materials and will vary according to the natural angle of repose for individual material types and compositions.

Where it is proposed to stock pile materials above the wall, consideration should be given to the maximum operating headroom, placement, height, stability and removal of the materials stored. In any case, the loading on walls should not exceed materials equivalent to a density of 1800kg/m³ stored at an angle of repose over 35 degrees. As a general rule, bays should not be disproportionately wide or shallow.

Start your storage estimation here