Abstract: A new idea that adopts a geotextile instead of a latex membrane to improve the performance of compaction-grouted soil nail, was proposed. Based on the self-developed device for testing geotextile’s filtration performance, a series of cement slurry filtration tests was carried out to study the influence of water-cement ratio, slurry volume and grouting pressure on the geotextile’s filtration performance. In addition, strength tests were carried out on cement blocks obtained from the slurry before and after filtration test. The main conclusions drawn are as follows. As the water-cement ratio increases, the final filtration mass of the slurry, the end time of the filtration and the mass flow rate increase accordingly, but the increment of the end time of filtration gradually decreases; the change in the volume of the slurry does not affect the mass flow rate. However, the end time of filtration linearly increases with the volume of the slurry. With the increase of the grouting pressure, the mass flow rate of the slurry gradually increases. At the same time, the increase rate of the expansion area of the geotextile is linearly increased with the grouting pressure. By adopting the geotextile, the water-cement ratio in the grout bulb is significantly reduced, which then largely improves the strength. This study is helpful for the application of the compaction-grouted soil nail by using geotextile.

Key words: compaction-grouted soil nail, grout bulb, geotextile, water-cement ratio, slurry volume, grouting pressure