Construction Guide of Soil Nail Wall

Introduction

Geotechnical engineering plays a pivotal role in the construction industry, providing essential solutions for challenging terrains and foundation requirements. Among the various techniques employed, soil nail walls and self-drilling soil nails stand out as effective methods for retaining structures, particularly in deep foundation pit excavations. However, the success of these engineering solutions relies heavily on meticulous construction quality inspection and control processes.

Construction Quality Inspection of Soil Nail Wall

1. Inspection of Raw Materials

To ensure the integrity of a soil nail wall, the inspection of raw materials is paramount. The quality of materials used in construction significantly impacts the structure's strength, deformation resistance, and overall stability. Rigorous examination of materials before use is essential to prevent potential weaknesses in the structure.

2. Grouting and Sprayed Concrete Strength

The strength of grouting and sprayed concrete is critical for the effectiveness of a soil nail wall. Rigorous testing during construction ensures that these materials meet the required standards, providing the necessary support and stability to the structure. Regular checks throughout the construction process guarantee that any possible deviations are addressed promptly.

3. Thickness Inspection of Sprayed Concrete

The thickness of sprayed concrete directly influences the structural integrity of the soil nail wall. Thorough inspection and measurement protocols should be implemented to verify that the applied concrete meets the specified thickness requirements, preventing potential vulnerabilities.

4. Soil Nail Pull-Out Resistance Test

Assessing the pull-out resistance of soil nails is fundamental to determining their effectiveness. Rigorous testing protocols should be in place to evaluate the load-bearing capacity of the soil nails, ensuring they can withstand the expected pressures and maintain stability during and after construction.

5. Measurement of Support Displacement

Monitoring support displacement provides valuable insights into the structural behavior during and after construction. Regular measurements enable the identification of potential issues, allowing for timely adjustments and ensuring the structure's stability over time.

6. Inspection of Floor State of Crack

The condition of the floor, including the presence of cracks, is indicative of the structural health of the soil nail wall. Comprehensive inspections should be carried out to detect any signs of distress or weakening, with immediate corrective measures implemented as needed.

7. Observation of Surrounding Infrastructure

The impact of soil nail wall construction extends beyond the structure itself. Observing the state of surrounding buildings, pipelines, and facilities is crucial to identifying potential risks or disturbances. Proactive measures can then be taken to mitigate any adverse effects on the environment.

8. Monitoring Underground Water and Leakage

Variations in underground water levels and potential leakage pose threats to the stability of the soil nail wall. Continuous monitoring is essential to detect any irregularities, allowing for the implementation of preventative measures and ensuring the long-term durability of the structure.

Construction Quality Control of Self-Drilling Soil Nail

1. Control of Design Parameters

Successful construction of self-drilling soil nails requires meticulous control of design parameters. Factors such as soil body properties, load, cohesion between soil and nails, length, density, inclination, and strength must be precisely managed to ensure the structure's stability and performance.

2. Orderly Excavation Depth and Speed

Coordinated excavation depth and speed are crucial to maintaining stability during self-drilling soil nail construction. Adhering to a well-planned schedule ensures that the construction process proceeds smoothly, with a focus on preventing instability and potential failures.

3. Coordination of Earth Excavation and Pit Support

The relationship between earth excavation and foundation pit support is symbiotic. Data analysis should be consistently performed to identify potential challenges and emergency measures must be swiftly implemented to address any unforeseen issues, ensuring the continuous progress of the construction.

4. Control of Positioning, Hole-Forming, Corrosion Prevention, and Grouting

The construction of self-drilling soil nails demands precise control over various aspects, including positioning, hole-forming, corrosion prevention, and grouting. Strict adherence to quality control measures at each stage is essential to guarantee the structural integrity and longevity of the soil nail system.

5. Monitoring Foundation Pit Deformation

Timely monitoring of foundation pit deformation is critical for assessing the overall health of the structure. Key monitoring parameters include roof horizontal deformation, settlements, and surrounding pipelines and building deformations.

Conclusion

The success of soil nail walls and self-drilling soil nail techniques relies heavily on robust construction quality inspection and control processes. By implementing comprehensive inspection protocols and maintaining strict control over various construction parameters, professionals in the geotechnical engineering industry can ensure the stability, durability, and long-term success of soil nail walls and self-drilling soil nail projects.