Introduction
Grouting is a widely used ground improvement technique in geotechnical engineering for enhancing soil strength, reducing permeability, and stabilizing foundations. Among the most common methods are Tube-à-Manchette (TAM) grouting and Jet grouting. While both aim to improve soil performance, their mechanisms, applications, and cost-effectiveness differ significantly. This article provides a comparative study of TAM grouting and jet grouting in the context of soil stabilization.
1. TAM Grouting: Overview
- Method: Grout is injected under controlled pressure through tube-à-manchette pipes with rubber sleeves.
- Mechanism: Forms discrete or overlapping grout bulbs, improving soil strength and reducing permeability.
- Suitable Soils: Permeable soils (sands, gravels) and fractured rock; limited penetration in fine silts/clays.
- Applications:
- Pre-excavation grouting in tunnels.
- Cut-off walls in dam foundations.
- Underpinning and settlement control in urban areas.
- Void filling in karstic formations.
2. Jet Grouting: Overview
- Method: High-pressure jets of grout (400–600 bar) erode, mix, and replace soil, forming soil-cement columns.
- Mechanism: In-situ soil mixing produces a homogeneous soil-cement matrix with improved strength and impermeability.
- Suitable Soils: Wide range, including silts and clays, where TAM grouting is less effective.
- Applications:
- Soil stabilization for deep excavations.
- Waterproof cut-off walls.
- Foundation improvement for bridges and high-rise buildings.
- Liquefaction mitigation in seismic areas.
3. Comparative Analysis
| Aspect | TAM Grouting | Jet Grouting |
| Grouting Mechanism | Injection through manchettes forms grout bulbs | High-pressure jet mixes soil and grout to form soil-cement columns |
| Soil Suitability | Best for sands, gravels, and fractured rocks | Applicable to almost all soils, including silts and clays |
| Permeability Control | Effective for seepage barriers in permeable soils | More uniform cut-off barriers, even in fine soils |
| Strength Improvement | Moderate increase in soil strength | High strength due to soil-cement column formation |
| Precision | Highly controlled and re-injectable at exact points | Less precise; larger treated zones but less targeted |
| Equipment Needs | Relatively simple (grout pumps, TAM pipes, packers) | Specialized rigs, high-pressure pumps, larger setup |
| Cost | Generally more economical | More expensive due to equipment and energy use |
| Environmental Impact | Lower disturbance, less spoil generated | Produces significant spoil and slurry requiring disposal |
| Construction Speed | Slower, multi-stage grouting required | Faster treatment of larger areas |
4. Advantages and Limitations
TAM Grouting
Advantages:
- High precision and control.
- Ability to re-inject through the same manchette.
- Minimal spoil and environmental disturbance.
Limitations: - Limited effectiveness in fine soils.
- Time-consuming process.
Jet Grouting
Advantages:
- Versatile across a wide range of soils.
- Produces strong and impermeable soil-cement columns.
- Faster execution in large areas.
Limitations: - Expensive and equipment-intensive.
- Generates large amounts of spoil requiring treatment.
- Less suitable in confined urban areas due to noise and spoil.
5. Selection Criteria
- TAM Grouting: Preferred in permeable soils, urban projects needing precision, and situations where re-injection may be required.
- Jet Grouting: Suitable for heterogeneous soils, projects requiring high-strength soil improvement, and cut-off walls in low-permeability formations.
Conclusion
Both TAM grouting and jet grouting are effective methods of soil stabilization, but their suitability depends on soil type, project scale, cost considerations, and environmental constraints. TAM grouting excels in precision and environmentally sensitive projects, while jet grouting offers versatility and high-strength improvements in a wider range of soils. An optimal solution often involves evaluating ground conditions and project objectives to select the most effective technique—or even combining both in complex geotechnical projects.
