Subgrade Stabilization, Pan Borneo Highway, Sarawak, Malaysia

For promoting the socioeconomic development of East Malaysia, the local government decided to improve the construction of the Pan Borneo Highway, which was commenced in 2015. The Sarawak segment of the highway will act as the main artery between the Sabah and Sarawak states. The newly constructed road extends approximately 1,060 km from Telok Melano to Merapok and crosses several swampy areas with poor soil conditions. Heavy rainfall is inevitable in this region and the infiltration of rainwater would further induce the function loss of the pavement as well as accelerates the formation of potholes; moreover, the passage of high volume traffic and heavy vehicles exceeding the bearing capacity of existing roads would exacerbate the current situation.

With poor soil condition and the problems caused by heavy rainfall,upgrading, widening and improving the condition of the route were simultaneously the most urgent and crucial issues to be resolved.

Unearthing solutions for the weak subgrade conditions and decreased road bearing capacity especially happened during rainy seasons; the pavement design introduces a fresh construction method – incorporate geosynthetic materials to improve the performance of the road. This method totally dispenses the large-scale soil replacement or treatment process which immensely reduces material and transportation costs. The site subgrade preparation initiates the construction, with the smooth installation of the ACETex^® ES geotextiles and prefabricated vertical drains (PVD) following up, and ACETex^® PET geotextiles follow the purpose of separation, filtration, drainage, and furthermore, functions as reinforcement. Lastly, the entire pavement structure is completed once backfilled to the required altitude. The usage of geosynthetic materials not only accelerates consolidation of the subgrade but also increases the bearing capacity of the weak soil layers, and allows the safe passage for heavy vehicles on the road. The project is expected to be completed in 2020 and millions of square meters of ACETex^® ES geotextiles will be applied.

The ACETex^® geotextiles pavement system has effectively converted unworkable ground conditions into a safe and stable high traffic route, so as to save countless transit hours and contribute to raising productivity of East Malaysia in the near future.