17/08/2026
🧠 ENGINEER EXPLAINS #01
# # 🚧 Why Does a Newly Built Road Sometimes Sink?
Have you ever noticed this?
A newly completed road looks perfectly smooth when it first opens.
But after some time…
Certain sections begin to sink.
The surface becomes uneven.
And when you drive over it, you may even feel the road becoming “wavy”.
The first reaction is often:
“This is a new road. Why is it already damaged?”
But from an engineer’s point of view, the problem may not actually be in the black asphalt that we can see.
The real problem could be hidden many metres beneath the road.
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# # # 🌴 We see a road. Engineers see what is underneath it.
Building roads in Sarawak comes with a particular challenge:
Soft ground.
In some areas, what looks like perfectly normal ground at the surface may actually have deep layers of peat or soft clay underneath.
Imagine placing a heavy book on a solid table.
Nothing much happens.
Now imagine placing the same book on a thick sponge.
The sponge slowly compresses under the weight.
The ground beneath a road can behave in a similar way.
A road, together with several metres of embankment fill, can be extremely heavy.
When all that weight is placed on very soft ground, the soil underneath gradually compresses.
One important process behind this is called:
Consolidation Settlement.
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# # # ⏳ The tricky part? It doesn't necessarily happen immediately.
This is what makes soft-ground engineering so interesting — and challenging.
When we construct a road today, the soft soil underneath doesn't say:
“Okay, I'll finish all my settlement today!” 😆
It takes time.
Sometimes months.
Sometimes years.
Soft clay contains water within its tiny pores.
When the weight of the road and embankment presses down on it, that water needs time to slowly escape.
As the water drains out, the soil gradually compresses.
And when the ground settles…the road above it settles too.
That's why engineers don't only ask:
“Can we build this road?”
We also need to ask:
“What will happen to this road five or ten years from now?”
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# # # 🏗️ So, what can engineers do?
This explains something you may have seen at construction sites.
Sometimes, before the actual road is even built, contractors place a huge amount of earth on the site.
And then…they wait.
People passing by may wonder:
“Why did they dump all that soil there and stop working?” 😂
But something very important may actually be happening underground.
One method is called **Preloading**.
In simple terms:
We deliberately place additional weight on the soft ground so that much of the expected settlement happens BEFORE the permanent road is completed.
Depending on the ground conditions, engineers may also use:
Prefabricated Vertical Drains (PVD), lightweight fill, geosynthetics, ground improvement, piling, or other engineering solutions.
There is no single solution that works everywhere.
Because every site is different.
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# # # 💰 Why don't we just use piles everywhere?
That's a fair question.
If soft ground is such a problem, why not simply support every road on piles?
Technically, piling may be one possible solution.
But engineering isn't only about asking:
“Can we build it?”
We also need to consider:
Safety. Cost. Construction time. Materials. Environmental impact. Maintenance.
If a RM10 million engineering solution can safely achieve the required performance, there may be little justification for using a RM50 million solution simply because it is “stronger”.
Good engineering isn't about choosing the most expensive solution.
It's about choosing:
The right solution, for the right place, for the right reason.
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So the next time you drive past a future road and see mountains of earth sitting there for months with seemingly “nothing happening”…
Remember:
It may not mean that nothing is happening.
Beneath the ground where we cannot see it,
one of the most important stages of the entire road construction may already be taking place.
And that's one of the fascinating things about civil engineering.
We see a road on the surface.
But the real story of that road…often begins underground.
🧠 ENGINEER EXPLAINS
Making complex engineering easy to understand.
Ir Sarawak
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