Trench Excavation
Trench Excavation
Trench excavation in hard rock is one of the most demanding tasks in civil engineering and utility construction. Whether you are installing pipelines, laying cables, or building foundations, cutting through solid rock is costly and time-consuming. Traditional methods like blasting or heavy mechanical breaking often cause excessive vibration, safety concerns, and disruption in urban or environmentally sensitive areas.
At Yamamoto, we provide a reliable alternative with our hydraulic rock splitter. Designed in Japan for precision, safety, and efficiency, our technology makes trench excavation in hard rock faster, safer, and more cost-effective.
What is trench excavation?
Trench excavation is the process of digging narrow, deep channels through soil or rock to install utilities, foundations, or drainage systems. While trenching in soil is straightforward, excavating trenches in competent rock formations presents unique challenges.
Common methods include:
Drilling and blasting – effective but often restricted near roads, buildings, and existing infrastructure.
Hydraulic breakers – widely used but slow, noisy, and expensive when large volumes of rock must be removed.
Chemical expansion agents – low-impact, but slow and less predictable.
The challenges of trench excavation in rock
Excavating trenches in rock involves specific hurdles:
- High cost – conventional methods require extensive machinery and labour.
- Noise and vibration – blasting and hammering can damage nearby structures and disturb communities.
- Regulatory restrictions – strict rules often prohibit blasting near utilities, pipelines, and residential areas.
- Overbreak and control – trench profiles must be precise; excessive break-out increases backfill and reinstatement costs.
- Time pressures – slow excavation delays pipeline, cable, or utility installation, raising overall project costs.
How Yamamoto Rock Splitter help in trench exavation
Yamamoto hydraulic rock splitter provide a safe, non-explosive solution for trenching in rock. After pre-drilling, the splitter’s wedges apply powerful hydraulic pressure, fracturing rock efficiently without vibration, noise, or flying debris.
How it works for trench excavation (typical workflow):
Using a Yamamoto Rock Splitter vertically works best for trenching excavation:
Drilling
- Drill split holes of Ø102mm x 1.5m depth for HRB-1000 splitter or Ø127mm x 2.5m or HRB-1700 splitter using a large size hydraulic crawler drill or jumbo drill rig.
- We recommend drilling in a staggered patter with 500-700mm of spacing between holes for HRB-1000 and 700-1000mm for HRB-1700, as illustrated in the diagram.
Splitting
- Mount splitter on a customised carrier equipped with a telescopic boom and rotator, we recommend using Yamamoto Arm-System YTB-1120.
- Start splitting the holes closest to the free face by inserting splitter wedges into the holes. Aim at working from the bottom and up to allow support from gravity.
- Split in 3 steps:
- First, insert half of the total length of the wedge and split.
- Second, further insert ¾ of the total length and split again.
- Finally, insert full length of wedge and split again.
Secondary breaking and mucking
- Work along the cracks caused by the splitter, use a hydraulic breaker mounted on a conventional excavator to break out the cracked rock.
- Use mucking method that suits each project, typically done with a standard excavator.
Benefits of Yamamoto Rock Splitter for trench excavation
- Cost-effective – reduce reliance on expensive blasting and large breakers.
- Low vibration and noise – safe to use near roads, utilities, and residential areas.
- Precise control – minimise overbreak, ensuring clean trench walls and reduced backfill.
- High productivity – split large volumes of rock quickly compared to hammering.
- Versatile – suitable for utility trenches, foundations, drainage, and road crossings.
- Environmentally friendly – no explosives, dust, or chemical residues.
With decades of global experience, Yamamoto is the trusted leader in hydraulic rock splitting, helping contractors deliver trenching projects safely and on schedule.
Trench Excavation FAQs
Trench excavation involves cutting narrow channels through hard rock for pipelines, cables, and foundations. It requires specialist equipment due to the hardness and density of rock.
Yes. Yamamoto hydraulic rock splitter fracture rock using hydraulic pressure, making them ideal for trenching in areas where blasting is restricted.
Hard rock requires heavy machinery, drilling, or blasting. In urban or infrastructure-heavy environments, vibration and safety risks make conventional methods impractical.
Breakers are effective for small jobs but inefficient for long, continuous trenches. Splitter fracture large volumes faster, with less noise and lower cost.
Yes. They are widely used for water mains, power cables, fibre optic installation, and other trenching projects in hard rock.
Depending on the size of the wedges, drill holes are between 102-127 mm and spaced between 600-1500 mm are required. The pattern depends on rock hardness and trench dimensions.