Abstract: Soil liquefaction under earthquake is a common phenomenon. Grouting technique was used to the anti-liquefaction of soil and a numerical calculation model of single pile was established. The dynamic response of a single pile was studied under the combined load of El Centro seismic waves with different peak accelerations and a uniform load on the top of the pile, and the influence of grouting on seismic performance of soil in single pile model was cleared. The research results showed that most of the loess and sand would be liquefied under the action of the 0.3g El Centro seismic wave. The bearing capacity of the pile foundation increased by 15.4% after grouting to loess and sand around pile sides. Under the 0.3g El Centro seismic wave, the foundation rotates. After the grouting of soil, the center of rotation shifts upwards, reducing the maximum dynamic displacement of the soil at the top of the loess by 35.3% and increasing the top of the sand by four times. 0.2 seconds before the earthquake, there is a peak acceleration in the loess and sand, while in the later stage of the earthquake, the acceleration fluctuation is relatively small, and there is a certain amplification effect on the top surface of the foundation. After the soil is reinforced by grouting, this amplification effect is effectively suppressed. The research results can provide a reference for anti-liquefaction treatment by grouting.

Key words: grouting, anti-liquefaction, dynamic response, Python secondary development