Experimental evaluation of performance of compaction-grouted soil nails using geotextile

A new idea that adopts a geotextile instead of a latex membrane to improve the performance of a pressure-grouted soil nail is proposed. First, based on the self-developed device for testing filtration performance of the geotextile, a series of cement slurry filtration tests are carried out to study the influences of the water-cement ratio, slurry volume and grouting pressure on its filtration performance. The variations in the filtration time and water-cement ratio under the changes in the aforementioned influencing factors during pressure grouting are obtained. Second, a series of penetration tests on the surrounding sands before and after filtration tests are conducted, and the strength improvement due to the infiltration of cohesive substances from grout slurry is subsequently evaluated. Third, the uniaxial compression tests are carried out on the cement blocks before and after the filtration tests, and it is found that the strength of the grout bulb (cement block) largely increases because the water-cement ratio in the grout bulb is significantly reduced during the filtration of the geotextile. Finally, two series of pull-out tests on the compaction-grouted soil nails with a geotextile and a latex membrane are carried out to verify the superiority of improving the compaction-grouted soil nails by the geotextile. This study is helpful for the optimization and application of the compaction-grouted soil nails by using the geotextile.