Track sub-structure analysis for a high speed train in Malaysia

A high-speed railway project in Malaysia for trains of speeds of up to 160 km/hr has been constructed between Rawang and Bidor (110 km long) in Peninsular Malaysia. The project requirement for track substructure analysis for the above stretch of works was studied by Ranhill Consulting. The geotechnical factors which are of importance for the subgrade performance are the strength and stiffness of the subgrade soil. Laboratory tests carried out, include grain size distribution, California Bearing Ratio and cyclic triaxial load test to determine the Threshold stress and the Resilient Modulus. Dynamic amplification factor and static deflection are influenced by the stiffness of the subgrade. Finite element analyses were carried out using a Young's modulus of 25 Mpa for subgrade to indicate a corresponding static deflection that is acceptable. Develop relationship between CBR and cyclic triaxial resilient modulus, undrained shear strength and resilient modulus as well as comparison of strength and resilient modulus measure in cyclic triaxial test. Based on this requirement, it was safely assessed that low embankment construction using Removal and Replacement Method have met the project's required criteria.