Performance comparison of revised reinforced subgrades with rigid wall for railways

초록

In these days, the use of concrete slab track on soil subgrade is being increased for railway construction in Korea. The concrete slab track requires less maintenance works but high levels of accuracy to construct than the ballasted track do. Because it is very difficult the concrete slab track to repair, we should take care of it from construction stage not to deform after train opening. The deformation of the track mainly comes from subgrade and ground settlement. To minimize subgrade settlement directly affecting track alignment and crack on track concrete layer, we do lots of measures during construction. These efforts enhance the serviceability in the aspects of riding comfort and decrease maintenance works of railway. Another important issue in Korea related with railway construction is cost down. To satisfy both aspects of not only performance enhancement but also construction costs down, we developed revised type of reinforced subgrades with rigid wall for railways. This study introduces geosynthetic reinforced subgrades having two different vertical spacing (0.3 and 0.4m) of one layer thickness after compaction and 3 different connection types (welded, wire fixed, and bolted types) between main reinforced bar of rigid wall and steel mesh covering backfill soil. To compare performance among them, full scale reinforced subgrades H(5m)*L(20m)*W(6.6m) were constructed in the Korea Railroad Research Institute as Figure 1. This paper summarizes the results of two static load tests for the reinforced subgrades.