23-05-2025
Elevated road among JKR Sarawak's key methods to counter peat soil construction challenges
Datuk Aidel Lariwoo
KUCHING (May 23): The Sarawak Public Works Department (JKR) continues to implement new technologies in constructing roads and bridges across coastal areas with peat soil.
Deputy Minister for Infrastructure and Port Development Datuk Aidel Lariwoo said this is to ensure safety, cost-effectiveness, and environmental sustainability.
In response to a question raised by Simunjan assemblyman Awla Dris at the State Legislative Assembly today, Aidel outlined the challenges posed by peat soil, which include low bearing capacity, high long-term compression, and acidic environments that accelerate structural erosion.
'JKR Sarawak constantly evaluates and adopts the latest technologies to ensure that the construction of roads and bridges on peat soil is safe, economical, and environmentally friendly,' he said.
Awla had asked whether there are new technologies for constructing roads and bridges in coastal areas that have peat soil.
Aidel said one of the key technologies currently in use is the elevated road method, which involves constructing raised road structures using support piles that avoid direct contact with peat soil to help reduce the risk of ground settlement and long-term damage to road surfaces.
He cited the road from Batang Samarahan Bridge to Batang Sadong Bridge under Package A1-B, as well as Jalan Teku to Pasai Siong in Sibu as projects applying this method.
Another method is the replacement technique, which involves excavating soft peat soil and replacing it with stronger and more stable fill materials such as sand, gravel, or compacted clay to enhance the load-bearing capacity of the road foundation.
The displacement method is also used, where heavy fill materials like sand or stone are placed directly on top of soft soil, forcing the weaker soil to move sideways without the need for excavation.
This approach improves stability without removing the existing ground.
To further stabilise the soil, the preloading and ground improvement method is applied, including the use of prefabricated vertical drains (PVD) combined with surcharge fill to accelerate the natural compression of soft soil.
Aidel explained that this combination reduces the time needed for soil compaction and minimises the risk of settlement after construction begins.
In addition, the deep soil mixing technique is used to strengthen swampy terrain.
This involves mixing cement with the soil using specialised equipment, which forms hardened columns that provide underground structural support.
Another advanced material used is Ultra-High-Performance Fibre Reinforced Cementitious Composite (UHPFRC), which is highly resistant to the penetration of chloride and sulphate that commonly degrade conventional concrete.
UHPFRC allows for longer bridge spans with slender cross-sections and offers greater resistance to acidic erosion.
Aidel said this material has been used in several road and bridge projects, including the road from Batang Sadong Bridge to Batang Lupar 1 Bridge under Package A2; Jalan Sebangan in Samarahan; Jalan Klid Medong Lebarassau in Dalat, Mukah; and the proposed road to Kampung Sungai Ijok in Samarahan.
To a supplementary question, Aidel highlighted that elevated roads provide several advantages over conventional methods.
They enable routes to be built over rivers, swamps, and densely populated areas, help reduce the need for land acquisition and compensation, and lessen environmental impact due to minimal disturbance of sensitive areas such as peatlands, forests, or riverbanks.
He also noted that the use of these new technologies can significantly reduce the need for long-term maintenance.
For instance, elevated roads supported by piles are effective in reducing uneven ground settlement and the resulting structural issues.
Moreover, technologies like PVD and deep soil mixing contribute to soil stability, which addresses one of the main causes of road deterioration.
Aidel also emphasised that under the Post-Covid-19 Development Strategy (PCDS) 2030, the Sarawak government is strongly committed to enhancing safety and quality in rural-urban road connectivity.
He said that the integration of new technologies in infrastructure projects plays a crucial role in supporting Sarawak's development. aidel lariwoo elevated road jkr sarawak lead peat soil
