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The Role of Geotechnical Engineering in Pavement Design

Aug 19th, 2024
Geotechnical engineers surveying road

You may not think much about the pavement beneath your feet, but a great deal of planning and preparation goes into the design, creation and laying of pavement. Pavement design in particular needs a lot of careful thought, as it is used in critical infrastructure projects such as the building of major highways, warehouses, large living and work complexes and transport hubs.

Because these areas see so much heavy traffic, finding out the best materials to make the pavement, the thickness it should be poured at, and any extra support under or beneath it that it may need are all critical to your project’s long-term success.

Geotechnical engineering plays a crucial role in the design of pavements in Melbourne, whether it’s a driveway or footpath, the road or the concrete of your workplace. Let’s discuss how vital it is and why companies that offer the services of geotechnical engineers are so important.

What Is Geotechnical Engineering?

What exactly is geotechnical engineering? This branch of civic engineering involves testing and analysing the earth under our feet, including soil, rocks and any construction materials like crushed rock. Geotechnical engineers are used at the beginning of most projects, where the earth is used to build or support structures. They are also a prominent part of major road projects.

Geotechnical engineering is sometimes known as geotechnics. By solving engineering problems using the mechanics of rocks and soil, geotechnical engineering has become a vital component of many large-scale projects across the world. It often overlaps with geology, geophysics and hydrology.

By testing soil samples at potential construction sites, design engineers test for things like soil strength, soil density and groundwater conditions. Another important aspect is monitoring the behaviours of the soil, and the soil’s response to different pressures and movements.

With this information, professional engineers can then determine the best way to start the building project.

Do you need geotechnical engineering in Melbourne? SITE Geotechnical is an expert in everything geotechnical. Explore the range of geotechnical services we offer right here online.

Pavement Drilling and Test Pitsand Material Sampling

How Geotechnical Engineering Informs Pavement Design

Now that we know what geotechnical engineering is, how does it relate to pavement design in Melbourne? First things first, any pavement project will start with geotechnical engineers performing a pavement investigation or survey. 

Here is what this kind of geotechnical investigation will involve:

  1. A visual walkover survey is conducted to discover any surface conditions and test any existing pavement.
  1. The subsurface will be tested using pavement drilling and other shallow excavation methods. 
  1. Samples of soil and any pavement are tested in a laboratory to discover more detailed information.

Performing a geotechnical investigation can save larger projects millions of dollars. It’s always worth having an experienced engineer on your site, like one from SITE Geotechnical.

Here are some of the most important ways you can inform your pavement design with geotechnical engineering:

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Get Expert Geotechnical Services
Contact SITE Geotechnical for thorough soil testing, drilling, and engineering solutions.

Discover The Perfect Composition For Your Pavement

How thick should your pavement be? Generally you would think the thicker the pavement layer the stronger it will be, however by using materials like concrete, asphalt or stabilisation, a thin pavement can work. In many cases, it’s better to have options as there can be conflicting aims that will often need to be taken into account.  By providing options, the client and contractors can balance any conflicting aims.

By testing the existing pavement materials and/or earth underneath your proposed project’s surface, you can determine the pavement composition requirements and ensure that your pavement will hold the expected traffic loadings without defects for decades. With appropriate pavement design, you can prevent the need for costly do-overs and fixes in the future.

Summary chart of recommended pavement options
An example chart of recommended pavement options by SITE Geotechnical.

This is especially important for industrial hardstand pavement, which has to withstand very heavy weights. This sort of pavement is seen in places like airports, warehouses and container yards.
SITE Geotechnical’s geotechnical engineers excel in innovative Pavement Design and can offer multiple options for your project.

Finding the Most Appropriate Pavement Material

How do you decide what type of pavement you will use? Asphalt or concrete are the main options, and each will play a crucial role in determining how long your pavement lasts. Each has its own physical properties, and geotechnical engineering can help you decide which one you will use in your construction project:

  • Asphalt: Sometimes referred to as bitumen, asphalt is well known for its shiny, black look, which is seen on many iconic long Australian roads. Asphalt is an affordable option that creates a smooth yet grippy surface, and it’s very easy to repair when needed.
  • Concrete: Lasting between 20-40 years, concrete is a long-lasting and durable material that is resistant to forming into ruts or dips over time. While not indestructible, it is resistant to damage and can be recycled after use. It is more expensive to lay than asphalt and is not as easy to fix when cracks or holes appear. 

Through an in-depth geotechnical analysis, geotechnical engineers can provide options on which type of pavement is best for your project.

SITE Geotechnical offers many different types of asphalt and concrete for different projects. Here is just a sample of our options:

AsphaltConcreteOther
Flexible asphalt surface pavementsRigid reinforced concrete pavementsFlexible bituminous stone seal pavements
Deep-strength or Full-depth asphalt pavementsConcrete segmental pavementsFlexible unsealed pavements

The experts at SITE Geotechnical use Pavement Computer Modelling (CIRCLY), a geotechnical design software, to assist with our pavement design process.

Contact Us Today
Get Expert Geotechnical Services
Contact SITE Geotechnical for thorough soil testing, drilling, and engineering solutions.

Add In Extra Support If Needed

Your pavement is more than just, well, pavement. Sometimes, additional elements will need to be either used as a base or mixed into the pavement solution to give it more flexibility, structure or strength. By performing a ground investigation, geotechnical engineers will be able to determine if your pavement requires a little extra support.

Pavement Stabilisation with Bituminous Additives (Foam Bitumen Stabilisation)

Pavement Stabilisation with Bituminous Additives

Foam Bitumen Stabilisation (FBS) is a technique that adds bitumen to existing pavement material to enhance the strength of existing unbound materials and make them more like asphalt, making the original pavement stronger and more capable of withstanding higher loads. FBS is a great way to rehabilitate existing roads. 

A geotechnical pavement investigation will be able to determine what your pavement will need to withstand the anticipated loadings and minimise future maintenance requirements.

Professionals like SITE Geotechnical will use the latest Publications And Design Tools to craft the perfect pavement plan.

Encourage Sustainability By Reusing Old Pavement Materials

Did you know your pavement can be made out of recycled materials and even existing materials within the road? By minimising the use of raw, natural resources, you can reduce your impact on the environment and save yourself some money at the same time. And choosing recycled materials doesn’t mean your pavement will be any less durable or strong. In fact, using recycled materials can actually boost the long-term performance of your pavement!

You can use recycled materials to stabilise pavement and prolong its lifespan, reducing your long-term costs, particularly for heavily used pavements. There are three types of materials used for recycled pavement, including:

  • Flexible pavements – also known as recycled pavement.
  • Rigid pavements – also known as recycled crushed concrete.
  • Solid waste materials – including glass, steel slag, plastic and fly ash.

A quality geotechnical analysis can help you decide if using recycled materials is a smart possibility for your construction project. 

As you can see, having an expert who can perform Construction Professional Services (CPS) Design on your site can only benefit your project! Choosing reputable geotechnical engineers, like those from SITE Geotechnical, can greatly assist in ensuring the best materials and practices are used for your project, while also saving you money as the more economical solution.

SITE Geotechnical offers pavement rehabilitation services by conducting Reports & Recommendations.

Geotechnical pavement Investigations

Trust SITE Geotechnical For Quality Pavement Design

Do you need geotechnical engineering in Melbourne? Reach out to the team at SITE Geotechnical, your trusted leaders for pavement design in Melbourne since 2005. We have a combined 80 years of experience in our field, which is showcased through our thorough and wide range of professional services designed to maximise efficiency while providing you with savings in cost.

Get in touch with our team by calling 1300 557 260 or filling out an enquiry form online. Our geotechnical engineers are excited to assist you with your next pavement project! For more information, check out our blog on the Benefits Of Conducting A Geotechnical Survey Before Construction and our pavement inspection case study.

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