When the line project passes through a large area of aeolian sand, cement mixing piles are often used to reinforce the subgrade, which can effectively improve the bearing capacity of the subgrade, but its anti-liquefaction effect is worthy of in-depth evaluation. Intermittent earthquakes cause more than one liquefaction of aeolian sand subgrade, so it is worth further research on the re-liquefaction characteristics of cement mixing piles in treatment of aeolian sand subgrade. In this paper, a real-time comparative test (pile reinforced area and unreinforced area) is carried out through a shaking table, and the liquefaction and re-liquefaction characteristics of the reinforced subgrade are mainly explored. The experimental model will produce the following results under 0.4g EL Centro wave excitation:(1) The pore pressure will have multiple peaks, causing the surface of the model to float or sink. The phenomenon will be weakened by experiencing multiple earthquakes of the same level or using pile reinforcement;(2) The deeper the burial depth, the longer the time for the pore pressure to reach the maximum peak value. After multiple vibrations, the corresponding time of the shallow layer in the unreinforced area and the deep layer in the reinforced area doubles;(3) The cement mixing pile can improve the liquefaction and re-liquefaction resistance of aeolian sand foundation, and the effect is best in the shallow foundation, with an increase of more than 30%, and the deeper the burial depth, the lower the effect;(4) After the subgrade has experienced a strong earthquake, its resistance to liquefaction will be improved, but the acceleration response during the next earthquake will increase significantly.

With the continuous development of traffic construction, road engineering inevitably crosses the aeolian sand river valley area. Compared with general sandy soil and silty soil, cohesionless aeolian sand foundation has similar properties with fluid and higher liquefaction potential. Precast cement pile can greatly improve the vertical bearing capacity of foundation, but this paper finds that it also has antiliquefaction effect when it is used to reinforce aeolian sand foundation. In addition, there may be more than one liquefaction of aeolian sand foundation in areas with frequent earthquakes. Therefore, this paper explores the liquefaction and reliquefaction characteristics of aeolian sand foundation reinforced by precast cement piles through shaking table test. The test results show that under the excitation of 0.4 g EL Centro wave: (1) the increase of pore pressure in aeolian sand foundation will have multiple instantaneous peaks, which will promote the surface to float or sink. The phenomenon will be weakened by multiple earthquakes or pile reinforcement. (2) The prefabricated cement pile can improve the liquefaction and reliquefaction resistance of aeolian sand foundation. The effect is the best in the shallow layer of the foundation, which is increased by more than 30%, and the deeper the buried depth, the lower the effect. (3) The antiliquefaction ability of foundation will be improved after strong earthquake, but the dynamic response will be significantly increased in the next earthquake. (4) When the aeolian sand foundation reinforced by precast cement piles is reliquefied, the main frequency of the foundation will migrate to low frequency. The liquefied layer will inhibit the low frequency (2 ~ 15 Hz) energy transfer and promote the high frequency (25~30 Hz) energy transfer. The results provide reference for antiliquefaction design of aeolian sand foundation and improve the application of precast cement pile in liquefied foundation.

With the vigorous development of railway and highway construction, tunnel construction often follows the mountains and rivers, crossing high-intensity landslide areas, and potential earthquakes triggering damage in areas including tunnel landslides have become a hot issue today. Based on this, this paper performs a shaker test on the tunnel-containing landslide body, inputs horizontal seismic waves, and tests the acceleration response data of different bits in the landslide body. By analyzing the temporal and frequency domain transformations of the acceleration response at different positions in the slope body combined with the deformation characteristics of the slope, and then analyzing the seismic response of the slope under the action of the front and back seismic sequences, the results show that (1) the existence of the tunnel has the effect of energy dissipation and vibration reduction, making the energy input at T8, and the measuring point on the upper part of the tunnel at the lowest. (2) When the seismic wave is transmitted, it will cause reflection around the tunnel, forming complex seismic wave field, resulting in the irregular distribution of acceleration amplification coefficient. (3) There is a high correlation between seismic responses of different levels. When the acceleration response of the preseismic response to the landslide-containing tunnel is not considered, the acceleration response of the postseismic response to the slope and the structure will be lower than the real value. (4) The sequence of failure at different locations of landslide mass containing tunnel is found through marginal spectrum analysis. It is concluded that the failure mode of landslide mass with tunnel is extrusion and sliding out of the middle slope. The research results can provide some reference for the reinforcement design of landslide with tunnel in high-intensity area.