Novel compaction grouting soil nail and pull-out test device thereof

Abstract

The invention belongs to the technical fields of civil engineering and geotechnical testing, and provides a novel compaction grouting soil nail and a pull-out test device thereof. The novel compactiongrouting soil nail is expanded by injecting cement slurry into special latex balls into to achieve compaction anchoring with a surrounding soil body. The pull-out test device comprises the novel compaction grouting soil nail, a test box, a grouting pressurization system, a pulling system, a measurement system and a data acquisition system and can be used for pulling tests of the novel compactiongrouting soil nail. The novel compaction grouting soil nail and the pull-out test device thereof have the beneficial effects that the novel compaction grouting soil nail can effectively avoid bleeding, penetration grouting or split grouting in the surrounding soil body; and the pull-out test device can be used for simulating compaction grouting processes under different saturation conditions and exploring the shear strength of a soil-nail interface and the response of the surrounding soil body to provide a basis for the design and safety assessment of the novel compaction grouting soil nail.

Description

technical field [0001] The application belongs to the technical fields of civil engineering and geotechnical testing, and in particular relates to a novel compacted grouting soil nail and a pull-out test device thereof. Background technique [0002] At present, soil nailing, as an effective reinforcement and stabilization technology, is widely used in excavation of foundation pits, retaining walls, slope stability and foundation reinforcement projects. Traditional soil nailing is arranged in a relatively dense As the main reinforcement means of the soil, the reinforcement anchor works together with the soil and the shotcrete surface to form a reinforced composite soil, so as to achieve the purpose of reinforcement and stability. [0003] However, the simple traditional test method has been used in the soil nail pull-out test. The test results are quite different from the actual stress-strain state of the soil nail in actual engineering use, and cannot be used to accurately r...

AI Technical Summary

Problems solved by technology

Indoor experimental research focuses more on the pull-out bearing capacity of traditional soil nails. During the grouting and pulling-out processes of new compacted grouted soil nails, especially when unsaturated soil strata are involved, the grouted soil nails compacted Afterwards, the influence of suction on the mechanical properties of soil and the effect of construction under different saturation conditions on the effect of soil compaction and reinforcement are far from limited.

A large number of engineering practices have shown that differences in soil (type, density, and volumetric water content, etc.) lead to large differences in the design of grouted soil nails, as well as large differences in the pullout resistance of grouted soil and the stability of reinforced soil. At the same time, due to the heterogeneity of the actual stratum, the effect of soil nailing by grouting soil nailing may not be ideal, and the research on the effect of soil nailing by high-pressure grouting soil nailing in unsaturated soil is far behind the engineering practice, and it is urgently needed. For further in-depth analysis, it is necessary to ascertain the soil response of grouting soil nails under different soil properties and grouting parameters, consider the influence of unsaturated state on the soil reinforced by the new compaction-grouting soil nails, and study the surrounding soil Response has extremely important practical significance to ensure the safety of reinforcement engineering and the effectiveness of reinforcement measures.

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