Construction New Technology No. 568
Individual vacuum consolidation
Vacuum soft-ground improvement with perforated/non-perforated spiral cylindrical drains and airtight connectors
Construction New Technology
No. 568
Vacuum soft-ground improvement with perforated/non-perforated spiral drains and airtight connectors
Method overview
- Native ground as sealing layer — vacuum consolidation without airtight sheet (No. 568)
- Direct vacuum on PVDs — individual vacuum and load transfer by depth
- Direct suction and discharge of inflow pore water
- SD method alone or with surcharge — isotropic consolidation and rapid fill
- Perforated/non-perforated crossing drain — sand-layer response
Method features
Lower surcharge, borrow, and complaint load — shear-failure prevention and shorter consolidation
Method comparison
Vertical drain · atmospheric vacuum · individual vacuum (suction drain)
| Item | Vertical drain | Atmospheric vacuum | Individual vacuum (SD) |
|---|---|---|---|
| Sealing | Not required | Airtight sheet | Native sealing layer |
| Load | Surcharge | Atmospheric vacuum + surcharge as needed | Vacuum on each drain |
| Aquifer response | Limited | Sheet leakage risk | Perforated/non-perforated crossing drain |
| Duration | Depends on drain spacing and fill | Shorter than drain-only | Shorter with isotropic vacuum |
| Fill height | Stability-limited | Reduced vs drain-only | Lower surcharge dependence |
Core components
- Spiral cylindrical drain — flow capacity and strain compliance
- Perforated/non-perforated crossing drain — sealing and aquifer conditions
- Fully airtight connector — leakage control at joints
- High-performance vacuum pump — claw pump
- Automatic vacuum control — zone-wise pressure
Specialized design and verification
- SD optimization program — MOLIT R&D · numerical analysis · over-design prevention
- Aquifer and revetment response — pre-construction check, trial boring/driving
- Vacuum and settlement control — staged 20→80 kPa · zone-wise management
Intellectual property — Construction New Technology and patent list