Dynamic Response Analysis of Soil around Curve Section Tunnel under Train Vibration Load

Abstract

To investigate the changes in soil dynamic response around the tunnel periphery under the vibration loads generated by train operation on curved sections, field measurements were carried out to observe void water pressure, water level, and settlement on the ground. Additionally, simulation modeling using MIDAS was employed to simulate and analyze the soil’s dynamic response under the impact of train loads. Based on the track stress diagram combined with the axle weight of the train, the transverse and vertical loads of the track are calculated. The corresponding parameters are entered into the train dynamic load table in the MIDAS/GTS NX dynamic analysis module, so as to simulate the vibration loads of the tunnel. The results show that the application of vibration load is an important reason for the change in pore water pressure during train operation. During the initial stages of train operation, the pore water pressure exhibits a significant increase, followed by a gradual decrease over time. The overall variation follows a seasonal pattern, with the pore pressure increasing as the depth of burial increases. The response of the soil around the tunnel to the vibration of the train is closely related to the location. The closer to the tunnel, the more sensitive the soil is to the vibration of the train, and the greater the amplitude and rate of pore pressure change and vertical deformation in the soil. The variation trend of groundwater level in soil is basically consistent with that of pore pressure, and the groundwater level is proportional to the depth. The dynamic response of the soil at the bottom of the curved tunnel decreases with the increase in the turning radius. The main influence range of the dynamic response is 0~15 m at the bottom of the tunnel. The excess pore water pressure generated by the soil gradually dissipates, and it can be predicted that the vibration of the train will not cause deformation damage to the surrounding soil.