The Evaluation of Lesser Himalayan Rocks for Ballast in the Nijgadh-Hetauda-Bharatpur Section of Proposed Electrified Mechi-Mahakali Railway, Nepal

Abstract

Railway have been important for the development of mountainous country like Nepal. The Government of Nepal has planned to establish various railway networks within the country such as the East-West Railway Project which is expected to play important role in connecting the eastern to western regions of Nepal to contribute socio-economic development of country. To construct a sustainable railway, highly durable and strong ballast material is required. The study area includes the Lower Nuwakot Group and Upper Nawakot Group of Nawakot Complex and the Bhimphedi Group of the Kathmandu Complex.
According to current standards (Indian Standards (I.S.)-1963, American Society for Testing and Materials (A.S.T.M.)-2015 and British Standards (B.S.)-2008), the various physical, strength, and durability properties were found to range as follows; the Flakiness Index from 1.58% to 10.62%, and the Elongation Index from 30.86% to 91,73%. The specific gravity ranged from 2224.43 kg/m3 to 2783.03 kg/m3, and the water absorption ranged from 0.47% to 1.41%. The total porosity and apparent porosity ranged from 16.34% to 27.87% and 12.76% to 25.32%, respectively. The Unconfined Compressive Strength ranged from 68.4 to 206.64MPa. In long term durability tests, the Los Angeles Abrasion value ranged from 13.35% to 46.18%, the Slake Durability Index value ranged from 96.52% to 99.1%, and the Sodium Sulfate Soundness value ranged from 0.095% to 2.10%. These properties show that the material have low porosity, high compactness, durable and shows resistant for weathering with low chemical reactivity which is suitable for railway ballast. For the use of railway ballast, Fagfog Quartzite, Dunga Quartzite from Hetauda and Malekhu area and Pandrang Quartzite of Bhimphedi area are very good and good respectively.