Assessement of Long Term Stability of Railway Bridge Abutment Using Geosynthetics Tube

Recently, as increasing railway construction, the damages of transition zone in railway are also increased. Thereafter the regulation of construction management has been tighten up in transitional zone. The transition zone in railway should be satisfied with two requirements; one is that the track support stiffness in this zone should be stiff enough comparing with concrete stiffness on abutment; the other one is that the lateral earth pressure should be small enough to the design value of active earth pressure. Compaction effort to be satisfied with tract support stiffness should be more than 95% degree of compaction. When this requirement is satisfied, the applied earth pressure is reached to the passive earth pressure which causes damages on the abutment. A construction method which is a MSW (Mechanically Stabilized Wall) using a geosynthetic, is proposed. Laboratory tests were performed to verify the MSW method and the applied repeated load is 180kN/m 2 which is 3 times larger than actual high speed train load used in design. Plate load tests were performed to measure track support stiffness and the values from the proposed method gave approximately 20% increased values than existing method. The measured lateral earth pressure from applied repeated loading test is decreased to 10~25% of existing method. Numerical analyses were performed to estimate long-term stability of the MSW method for 10 years, and the analysis results shows that the lateral earth pressure is decreased to 15% of that from existing method. The long-term stability of the MSW method is also satisfied. Therefore, the proposed MSW method can be greatly useful to solve problems in transition zone in railway abutments.