Subsurface Investigation on Federal Route Failure at Pengkalan Raja, Pontian, Johor

Abstract Road settlement is one of the major problems that often occurs in soft soil ground areas. The combination destructive test method (trial pit, Standard Penetration Test (SPT) and borehole) non-destructive by using seismic refraction, electrical resistivity tomography (ERT) penetrating radar (GPR) were performed to identify factor causing tension cracks road differential settlement. study area selected at Section 39 50, Federal Route (FT005) Johor Bahru Malacca (Pengkalan Raja, Pontian, Johor) because severe condition which may cause an accident user. This paper presenting result a test. From results borehole, seismic, ERT, was underlaid 7-12m compressible layer. GPR image showed existing concrete slab below has deviated from its original position not function as foundation road. In conclusion, best approach identifying underground failure it fastest solution, economical suitable high volume traffic.