Not all of the plots in the UAE are flat. The fundamental structural issue is soil pushing against a wall on one side of the wall, and a wall which must hold the line without failing, whether the slope is a slope site, an elevated road corridor, a basement excavation or a variable terrain farm. It’s the role of a retaining wall, and one of the more expensive errors a project can make is to get the engineering right. This guide will discuss the type of systems available, what to look for before you select a precast concrete retaining wall supplier in UAE, and the process of installing them.
Role of Retaining Walls in UAE Construction
Where there is a difference in ground level on either side of a wall, a retaining wall is used to hold the soil back, such as a raised plot next to a lower road, an excavation in the basement, a terraced landscape or a compound wall where the ground on the inside of a property is raised or lowered from the outside. A retaining wall is defined as a wall that is used to hold back soil and has a lateral soil load placed on it, as opposed to a traditional boundary wall which does not.
For many of the same reasons it dominates other wall categories in the UAE, precast concrete has become the wall of choice for retaining walls here: The precast concrete components are cast and cured under factory conditions, resulting in uniform structural strength and resistance to the environmental challenges of the UAE’s climate, such as temperature, humidity, and yet, in some regions, saline ground water. Precast retaining systems are also much quicker to install than cast-in-place systems because the structural components are ready to place, not needing to be poured in place and allowed to cure before load is placed on the system.
Across the UAE, from landscaping and slope stabilisation work to road and infrastructure corridors, basement and below-grade projects, agricultural terracing and compound walls on sites with variable ground levels, retaining walls can be found on a variety of projects. In all instances, the wall is not for decoration. When it doesn’t work, the results can be soil erosion, soil drainage issues, and serious structural issues to whatever is above or around it.
Different Types of Precast Concrete Retaining Wall Suppliers Systems Available in the UAE
The design of retaining walls is very site specific and relies on the height of the soils being retained, the site conditions and the application itself. So, let’s take a look at the different types of the main system.
Gravity Retaining Walls
Use mass and weight of the wall to counteract soil pressure, typically for heights not to exceed 3-4 feet. They’re simple to understand and don’t have a lot of holding power before they get too unwieldy to be useful.
Cantilever Retaining Walls
A reinforced base slab with wall stem to resist overturning and sliding forces that can be achieved by retaining greater heights than gravity walls with no additional material usage. One of the more frequently used precast designs for retaining walls of medium height.
Panel-and-Column Retaining Systems
A variation of the traditional panel and column boundary wall system, designed for retaining loads instead of screening. Common use where a retaining wall is also required to be a compound or boundary wall.
Landscape and Slope Stabilisation Walls
Precast retaining walls for terraced gardens, sloped landscaping and erosion control are a lower height, and are often visible as part of the final landscape design, which may include a variety of surface finishes.
Basement and Below-Grade Retaining Walls
Used for structures below grade where excavation is required for a basement or other structure where the soil around the structure will remain permanently in place and will be subjected to greater structural loading, and sometimes in conjunction with waterproofing detailing.
Factors to Consider When Looking at a Precast Concrete Retaining Wall Suppliers UAE
Among the precast products, retaining walls are the most structurally at risk, and the selection of a supplier should be given special attention.
In-House Structural Engineering Skills
This is the one most crucial item for a retaining wall in particular. Soil pressure estimates, drainage layouts and reinforcement design are all required – not all precast suppliers have this expertise in house. Specifically question whether the supplier has their own engineering team in charge of the retaining wall design or outsourced.
Soil and Site Assessment
A reliable supplier will want to know about your site’s soil conditions, height above ground and ground water conditions before quoting a system, not just any system, but your particular site soil conditions.
Drainage Design
A poorly designed drainage system is more likely to cause failure of a retaining wall than soil pressure. Ensure that the supplier’s design provides for adequate drainage (weep holes, drainage layers or backfill specifications) to reduce hydrostatic pressure behind the wall.
Structural Documentation and Certifications
Request compressive strength information, reinforcement details and compliance documentation in accordance with the relevant structural codes in UAE. If this documentation is not provided, then a load bearing structure such as a retaining wall will not stand.
Track Record with Similar Applications
A good supplier of landscape retaining walls might not be the best supplier for basement or infrastructure scale retaining walls. Request details of projects that have been finished which are similar in terms of retained height and application to your project.
Lead Times and Installation Support
Installation of retaining walls is often done in concert with excavation and foundation work for a larger project. Check the timelines and if the supplier provides installation assistance or works with the contractor you have assigned.
Leading Precast Concrete Retaining Wall Suppliers in UAE
1. KKK Precast Concrete Industry LLC
Providing precast concrete wall system solutions for residential, commercial, agricultural and industrial projects throughout Dubai, Abu Dhabi and Sharjah, KKK Precast’s precast elements are designed to fit the unique site and structural conditions of each project, such as projects that have retaining sections.
2. Gulf Precast
Gulf Precast manufacturers precast retaining wall systems that are ideal for landscaping, boundary support, and are valued for its structural capability, resistance to environmental stresses and speed of installation across project sites around the UAE.
3. Solid Rock Concrete Works (SRC Precast)
With a team of experienced designers and project managers, SRC Precast has a large range of precast products that can be manufactured in Umm Al Quwain to meet the various requirements of a specific site, ranging from boundary and retaining wall products through to all other precast product ranges.
4. Abu Dhabi Precast (ADP)
Abu Dhabi Precast has been in the UAE market for more than 20 years, manufacturing and delivering precast and pre-stressed concrete solutions for a wide range of large-scale structures, such as precast and pre-stressed retaining and load-bearing wall systems designed for challenging site conditions.
5. Al Watania
Al Watania is a precast walls and structural components specialist based in Umm Al Quwain that specialises in very complex design specifications for large and small scale work without compromising on quality.
6. Saad Precast
Since 2008, Saad Precast has been producing boundary wall panels, columns and bespoke precast components in the UAE and Oman, specializing in cost-competitive projects in the Northern Emirates.
7. LEGO Precast
LEGO Precast has installed thousands of kilometres of precast boundary and retaining walls throughout Dubai, specialising in the accuracy of design and customisation of precast structures to meet the requirements of projects that demand specific structural solutions.
The Retaining Wall Installation Process
Installing retaining walls is sometimes more engineering intensive than a normal boundary wall because of the various loads that are imposed on the retaining wall structure.
Site Survey and Soil Assessment
The engineering team of the supplier conducts a survey of the ground level, soil type, and the desired height of the structure’s building, before any design work begins, as these factors directly influence the structural system required.
Structural Design and Drainage Planning
Engineering calculations for soil pressure, reinforcing and drainage detailing is completed and usually submitted as part of the structural documentation to be approved.
Foundation Work
Footings are cast on the site and allowed sufficient curing time to do its job, and that should not be rushed, especially for the loads that a retaining wall’s foundation will have to carry.
Delivery and Erection
The precast wall components are delivered and lifted to site by crane and drainage is installed at the stage of lifting, not afterwards.
Backfilling
The backfill is placed and compacted behind the wall in a controlled manner to prevent an overload on the wall prior to design strength.
UAE Approvals and Regulations for Precast Concrete Retaining Wall Suppliers UAE
As with structural projects, retaining walls usually need engineering approval from the relevant emirate authority – Dubai Municipality, Department of Municipalities and Transport, Abu Dhabi, Sharjah Municipality or equivalent elsewhere – as part of the overall structural submission of the project. Typically, this involves the soil investigation data, structural calculations and drainage design.
A supplier who has been through the process of retaining walls in the U.A.E should be able to guide you through this process as well as assist you with the structural documentation if necessary, instead of entirely relying on a separate consultant.
Final Thoughts on Precast Concrete Retaining Wall Suppliers in UAE
Retaining walls are more engineering-intensive than many precast products, so it’s particularly critical that the supplier is selected. As well as the retaining wall capability, KKK Precast, Gulf Precast and SRC Precast offer a range of precast products, while Al Watania, Saad Precast and LEGO Precast have specific experience in structural wall and boundary work, in various scales of project.
Before hiring a supplier, make sure that they have the engineering processes necessary to manufacture your product, ask specifically about drainage design, and ask them for references that have a similar retained height as your project. An engineered retaining wall that’s done properly the first time is invisible, that’s what you want from a retaining wall.