Full-scale performances of the slab track subgrade filled with basalt fiber-reinforced foamed concrete

In China, foamed concrete has been employed to solve the issue of differential settlement in high-speed railway subgrades. However, foamed concrete still needs reinforcement to improve the crack resistance and the performances of the foamed concrete subgrade need more in-depth research. A series of tests, including uniaxial compressive strength and dynamic triaxial tests, are conducted to comprehensively investigate the effects of basalt fiber reinforcement on the mechanical properties of foamed concrete with densities of 700 kg/m3 and 1000 kg/m3. Additionally, a full-scale model of the foamed concrete subgrade are established, and simulated loading is performed. The diffusion patterns of dynamic stress and dynamic acceleration within the subgrade are explored, and experimental formulas are proposed to calculate the attenuation coefficients of these two indices along the depth and width of the subgrade. Furthermore, dynamic displacement and cumulative settlement are analyzed to assess the stability of the subgrade. The findings consistently provide valuable references for the design and construction of foamed concrete subgrades.