You may or may not have experienced issues with heaving on a project before – if you’ve been lucky enough to sidestep it, then it can be surprisingly easy to underestimate the scale of the problems that it can create. It’s a relatively common issue that can cause serious delays on construction projects, especially mini piling. And as mini piling contractors with a wealth of expertise behind us here at Vxcel, we’ve had our fair share of experience with it ourselves! So then, in case you need a quick primer (or a quick refresher), here are the key points you need to know about heaving, and how it can affect mini piling.
The biggest causes of soil heaving
Basically, soil heaving occurs when the ground beneath a structure expands and rises. It’s often caused by an increase in moisture content, which is particularly common in clay-rich soils that are highly susceptible to water absorption. When these soils absorb water, they swell and expand, which causes the ground to heave upwards. Equally, when they lose moisture, they can contract and shrink. This process of expansion and contraction can lead to significant ground movement, especially if it happens repeatedly over a longer period.
So that’s how soil heaving works – here are the main causes of it.
- Water infiltration. Excessive rain, leaks from plumbing, or poor drainage can all introduce excess moisture into the soil, which can sometimes lead to heaving. As we’ve touched on above, this is particularly problematic in areas with heavy clay soils, which are prone to swelling when wet.
- Frost heave. In colder climates, water in the soil can freeze and expand, pushing the soil upwards. This process is known as frost heaving, and it can cause significant ground movement. Thankfully it’s not quite as common here in the relatively mild UK climate, but it can and does happen.
- Vegetation. The roots of trees and large shrubs can also contribute to soil heaving. As roots grow and spread, they can displace soil and cause it to heave. What’s more, the removal of large trees or shrubs can lead to changes in soil moisture levels, causing further heaving or settlement.
Now that you know what’s potentially causing soil heaving, here’s what to look out for.
The telltale signs of heaving around mini piles
As with any developing issue around construction sites, if heaving is spotted early, it can go a long way to helping you manage and resolve the issue. That’s a brilliant reason to make sure both you and your team are all up to speed on how to spot some of the biggest developing tell-tale signs of heaving. These include the following!
- Cracks in foundations or walls. One of the most visible signs of soil heaving is the appearance of cracks in foundations, walls, or floors. These cracks are typically caused by uneven ground movement, and they can indicate that the soil beneath the structure is expanding and contracting.
- Uneven or raised floors. As the soil beneath a structure heaves, it can cause floors to become raised and uneven. This is often accompanied by gaps between the floor and the baseboards or skirting boards.
- Sticking doors and windows. Heaving can cause door and window frames to become misaligned, which can lead to doors and windows that “stick”, or no longer close properly. This is a generally a very clear sign that the ground beneath the structure is moving.
- Bulging or dipping in the ground surface. Visible bulging or dips in the ground surface around mini piles can also indicate soil heaving. These deformations in the landscape are caused by the expansion and contraction of the soil and can affect the stability of the mini piles. They can be quite unpleasant to stumble across, particularly if you do it literally!
How can heaving affect mini piling projects?
Heaving can have a significant impact on mini piling projects. The upward pressure exerted by expanding soil can cause mini piles to shift, tilt, or even lift out of the ground. It’s a really serious issue – this movement can compromise the structural integrity of the building or structure supported by the mini piles.
What’s more, soil heaving can place additional stress on mini piles, leading to cracks or fractures in the piles themselves. This damage can reduce the load-bearing capacity of the piles, and increase the risk of structural failure. In extreme cases, soil heaving can cause the complete collapse of a structure.
One of the most important (and effective) ways to mitigate these risks is to monitor soil movement throughout a mini piling project. That can help you to spot early signs of soil heaving, which can often make a decisive difference in your ability to deal with them. Let’s move on to that section now!
A quick roundup of the best methods to mitigate heaving effects
As with so many issues on construction sites, what matters most when it comes to dealing with heaving is prompt and decisive action. If you’re not exactly sure which method might be best to deal with the immediate problem at hand, you can always ask one of our experts here at Vxcel, and we’ll be happy to advise! Some of the most effective techniques typically used to deal with heaving include:
- Improving site drainage. Ensuring that water drains away from the site effectively can help prevent excess moisture from accumulating in the soil. This might involve installing drainage channels, sump pumps, or rain gardens to divert water away from the foundation.
- Using heave-resistant materials. In areas prone to heaving, using heave-resistant materials can help minimise the impact on the structure. These materials may include specialised piling systems, or foundation types that can accommodate ground movement.
- Soil stabilisation techniques. Soil stabilisation methods, such as injecting chemicals or using geotextiles, can help reduce soil expansion and contraction. This can help to minimise ground movement and reduce the risk of heaving.
- Controlling vegetation. Managing vegetation around the site can help prevent soil heaving caused by root growth or changes in soil moisture levels. This might involve removing large trees or shrubs, planting vegetation with less aggressive root systems, or installing root barriers.
Those are just a couple of the go-to actions we’d recommend – but again, if you’re ever unsure of exactly how to deal with a suspected case of heaving, don’t hesitate to get in touch with our team. Just give us a call on 01254 314010, and we’ll be happy to see how we can help!
As highly experienced mini piling contractors here at Vxcel, we have well over a decade of delivering exceptional results – encompassing domestic projects, commercial properties, and industrial warehouses. To find out what we’ve achieved for previous customers, feel free to take a look through our case studies!