###### Abstract  
The performance of traditional steady grouting is sometimes limited; therefore, a new high-frequency pulsed grouting method is proposed. Through the CFD method, this paper studies the cement slurry penetration performance of cyclic grouting under the influence of pulsating pressure and steady pressure. Firstly, the penetration shape and flow fields of the two grouting methods are investigated. Secondly, the effects of pulsation parameters on penetration performance are studied. Finally, the influence of various working conditions, such as soil properties, grout parameters, grouting pipe length, and back pressure, on penetration distance is also investigated. The results show that pulsating grouting achieves better penetration performance compared with steady pressure grouting. With the increase in frequency, pulsating grouting exhibits superior performance, while with the increase in pulsation amplitude, the penetration distance initially increases and then decreases. This is because part of the pulsating pressure is lower than the back pressure, which weakens the pulsating effect. As viscosity and back pressure increase and as porosity and particle size decrease, the proportion of lateral diffusion in pulsating grouting relative to steady pressure grouting increases. This indicates that lateral penetration performance achieves optimal results under high-flow-resistance conditions. However, when the flow resistance becomes excessively high, the vertical penetration distance may be affected. This study is expected to improve the grouting efficiency and provide a better understanding of pulsating grouting design and operation. c 2023 13 11919 113 127 October 2023  
In recent years, pulsating grouting has been proposed and has attracted extensive attention. This pulsating method is mainly achieved through intermittent pressure provided with the pressure pump. [PERSON] [6] presented that pulsating pressure can alleviate particle blockage phenomena, which is beneficial for slurry penetration. [PERSON] [7] found that pulsating pressure can induce a transition between laminar and turbulent flow fields, reducing flow resistance and alleviating slurry filtration. [PERSON] [5] presented that pulsating pressure can weaken the guiding effect of dominant channels, making the grout penetration more controllable. [PERSON] [8] investigated the mechanical behavior of pulsating grouting, and it was found that the strength of the stone body grouted using pulsating pressure is higher. Through electron microscope scans, [PERSON] [4] found that the soil aggregates grouted using pulsating grouting exhibit a clustered structure, which is denser compared to the flocculent structure observed after steady pressure grouting. However, due to the absence of pressure during pulsation intervals, researchers found that intermittent pressure grouting may sometimes reduce the slurry flow rate and weaken the advantage of the pulsation effect [9]. Hence, research on the effect of pulsating frequency on grouting performance is conducted. [PERSON] [10] found that high-frequency oscillations can reduce the viscosity of the slurry, thereby increasing the penetration distance within rock fractures. [PERSON] [11] used a 'Haskel' pump to generate continuous pressure pulsations (3 Hz) and found that this dynamic pressure significantly enhanced the grouting efficiency. Research conducted by [PERSON] [7] and [PERSON] [5] also suggests that the higher frequency is more advantageous for the penetration of the slurry. However, the effects of pulsation parameters, soil parameters, and various working parameters on the slurry require further research. Hence, in order to promote the application of efficient grouting technology in soil layers, this study compared the penetration performance of high-frequency pulsating grouting with steady pressure grouting. Subsequently, this paper studied the mechanism for the superior performance of pulsating grouting.