Central Spine Road, Pahang.
The Central Spine Road is a federal highway project crossing the central peninsular Malaysian backbone, connecting alignment segments through Pahang and adjacent states. The route traverses hill country, residual saprolite, and varied subgrade conditions. Our group delivered approximately 65,000 m² of geosynthetic scope on this project across six distinct geosynthetic systems applied in combination, making it one of the most multi-system geosynthetic project references in our portfolio.
Federal highway through hill country.
The Central Spine Road alignment crosses interior Pahang hill country with a mix of cut slopes through weathered saprolite, fill slopes on the downslope side of the route, and bridge crossings over river valleys. The geosynthetic strategy combined multiple categories to address each part of the cross-section: MSE wall systems where vertical retention was needed, RSS where vegetated battered slopes were acceptable, basal reinforcement on weaker subgrade, road-base reinforcement to manage CBR variability in cut sections, drainage geocomposite behind walls and at slope toes, and erosion-control over exposed slope faces.
Six geosynthetic categories combined.
- MSE wall (geogrid + facing): Reinforced fill with StrataGrid PET uniaxial plus modular or precast facing where vertical retention served the alignment.
- Reinforced Soil Slope (RSS): Geogrid PET in lifts with vegetated facing on slopes where 1V:1H to 1V:0.5H batters were acceptable.
- Road base reinforcement: Biaxial geogrid at the sub-base interface where subgrade CBR was variable.
- Basal reinforcement (HSR): Woven PET basal mat below fill over weaker subgrade segments.
- Drainage geocomposite: StrataDrain behind retaining walls and at slope toes, replacing graded gravel chimney drains.
- Erosion-control / vegetated facing: Geocell + topsoil + grass on cut and fill slope faces.
The use of six systems on a single project is unusual; most projects use two or three. The Central Spine Road scope is therefore a particularly useful reference for projects where multiple geosynthetic categories must be specified, supplied, and installed together by a single sub-contractor and supplier under a coordinated programme.
What multi-system scope teaches.
- Single accountability across systems reduces interface risk. When MSE walls, RSS, road base, basal mat, drainage, and erosion control are all supplied through one distributor (Starwall) and installed by one contractor (Infraconcrete), the inter-system interfaces (where one geosynthetic meets another) are easier to detail and execute correctly.
- Tropical drainage management is the long-term performance variable. Concentrated rainfall on hill-country alignments puts substantial water into the slope system. Each of the six systems has a water-management role; designing them together is more robust than designing them in isolation.
- Productivity benefits from shared crew and plant. When multiple geosynthetic systems share the same crew, plant, supervision, and QA system, installation productivity improves because crews learn each system once and apply across the alignment.
Code references.
| Standard / code | Used for |
|---|---|
| JKR-SPJ Section 7 | Earthworks and slope geosynthetics |
| BS 8006-1 and 8006-2 | MSE wall + RSS + basal reinforcement design |
| FHWA-NHI-10-024 | MSE wall cross-check |
| Giroud-Han 2004 | Road base reinforcement on weak subgrade |
| FHWA-HEC-15 | Drainage with geocell where applicable |
| ASTM and ISO test methods | Material property verification |
Where to read more.
The Central Spine Road project is documented in JKR publications and Malaysian press coverage. The route, contract structure, and works programme are matters of public record. Our role on the project is described from our own work records.
Related references.
Multi-system geosynthetic scope for your project?
WhatsApp the alignment + ground conditions. We will design the integrated geosynthetic package.