Dynamic Response Characteristics of Foundation of Mined-out Areas under High-speed Railway Load

mined-out areas (MOA) under the high-speed railway (HSR) load is
important for predicting settlement and safety assessment of the
foundation. Taking MOA of Dianshang under the Taiyuan-Jiaozuo
HSR as the engineering background, the model experiments and
numerical analysis were employed to reveal the dynamic response of
both subgrade and the foundation of the HSR, as well as the
attenuation law of the acceleration in the overlying strata of the
MOA. Results show that within the full frequency range of the HSR
load, the dynamic response of the foundation increases with the
increase in load frequency. When the depth exceeds 6 m, the dynamic
response of the foundation initially increases and subsequently
decreases with the increase in load frequency. Contrasted with singlepoint loading, the superposition effect and moving effect of the HSR
load will form a dynamic response superposition zone within 1-4 m
below the subgrade, leading to a significant enhancement of the
dynamic response of the foundation. Compared to HSR axle load, the
driving speed of HSR has a greater impact on the acceleration of both
the subgrade and foundation. The obtained conclusions provide a
reference for the safety operation of the HSR crossing the MOA.