Case Study of Railway Substructure improvement by Geo-Reinforcement Materials

Abstract

The railway ballasted track structure is consisting of two parts: superstructure and substructure. The completeness of two parts affects to traffic safety and riding comfort of the passengers. Previously, the track maintenance has limit due to the limited period for maintenance. Thus, the maintenance planning is focused on the replacement of superstructure materials, such as rails, fasteners, and sleepers without taking into account the ballast layer which is a significant material for supporting the loads. The deterioration of ballast layer has resulted into vary damages such as the mud pumping. due to the contamination of the fine particle in ballast layer and ballast crushing including the performance of drainage. From this study of the railway in the southern-central line from Chumphon to Nakhon Si Thammarat, which has a distance of approximately 557 kilometers, found that track quality index (TQI) has range into 20-40% in 25 kilometers which has to be improved. In the general practice of Civil Engineering Department State Railway of Thailand have been making drainage path of water form sleeper and fill more ballast for temporarily maintenance. Therefore, the use of reinforcing materials is one of the methods used to solve this problem. This paper presents a method for improving the substructure with geotextile and geogrid materials to improve the performance and sperate of ballast and subgrade soil.