Experimental Study on Lateral Resistance of Optimized Ⅲc Sleeper with Different Frame Types

To optimize the geometry of the Ⅲc mono-block sleeper and reveal the variation characteristics of the ballast bed lateral resistance before and after optimization, three different frame sleepers were designed and fabricated by adding concrete blocks to specific parts of the Ⅲc mono-block sleeper. Based on the ballast bed lateral resistance test, The frame sleepers and Ⅲc mono-block sleeper were compared for different ballast bed cross-sections (shoulder width 300 mm, shoulder height 0 mm; shoulder width 500 mm, shoulder height 0 mm; shoulder width 500 mm, and shoulder height 150 mm). The study shows that each frame sleeper can effectively increase lateral resistance with different ballast bed cross-sections. Furthermore, compared with the Ⅲc mono-block sleeper, there is 37.8%-50.0% increase in lateral resistance for frame sleeper type A(end-winged sleeper), 25.5%-41.0% increase for frame sleeper type B(middle-winged sleeper), and 13.3%-23.0% increase for frame sleeper type C(bumped sleeper).