This case study documents the selection, deployment, and quality outcomes of CDM D800 pile technology at the Gia Binh Airport infrastructure project, Bac Ninh Province, Vietnam — with equipment supplied by Viet Sinh.
Project Overview at a Glance
| Item | Details |
| Project | Gia Binh Airport, Bac Ninh Province |
| Technology | CDM (Cement Deep Mixing) - D800mm pile diameter |
| CDM Drill Heads | 30 units: VKIZAI 90D (90kW) & VKIZAI 110D (110kW) |
| Treatment Depth | 15 - 22 m |
| Schedule | Completed on time per contract |
| Load Capacity | ≥ 200 kPa - 105% of design requirement |
Background & Technical Challenges
The Gia Binh Airport project (Bac Ninh Province) is situated on a wide-area soft ground zone characterised by low-lying terrain with multiple layers of soft-to-flow plastic clay extending 10 to 20 metres in depth. This represents an exceptionally unfavourable geotechnical condition for airport infrastructure, where allowable differential settlement must not exceed 5 cm throughout the operational lifespan of the facility.
Key Technical Challenges
• Highly organic soil content with low reactivity to standard Portland cement, requiring trial mix optimisation prior to full-scale construction.
• Construction site in close proximity to residential areas - strict vibration and noise control requirements enforced throughout.
• Tight contractual schedule with zero tolerance for delays affecting the structural works package.
• Highly organic soil content with low reactivity to standard Portland cement, requiring trial mix optimisation prior to full-scale construction.
• Construction site in close proximity to residential areas - strict vibration and noise control requirements enforced throughout.
• Tight contractual schedule with zero tolerance for delays affecting the structural works package.
Selected Solution: CDM (Cement Deep Mixing) Technology - D800
Following comprehensive geotechnical analysis, the engineering team selected Cement Deep Mixing (CDM) with D800mm pile diameter as the optimal solution — offering superior cost-to-performance ratio compared to precast concrete piles in saturated soft clay conditions.
Construction Equipment
The project deployed specialist CDM rigs fitted with multi-axis D800 drill heads, manufactured by Viet Sinh in Vietnam. Viet Sinh supplied 30 CDM drill head units (VKIZAI 90D & 110D), representing approximately 25–40% of total CDM drilling capacity across the entire airport ground improvement works.
CDM D800 Pile Construction Process
Step 1 - Setting Out & Site Preparation
Pile centres were set out using a total station with positional tolerance ≤ 50 mm. The working platform was compacted to provide a stable surface for CDM rig movement, ensuring pile verticality throughout drilling.
Step 2 - Drill Head Penetration Phase
The D800 drill head was advanced at approximately 25 rpm. Cement slurry injection commenced during penetration to lubricate the auger and initiate early mixing. Penetration rate: 0.5-1.0 m/min depending on soil stratigraphy.
Step 3 - Slurry Injection & Withdrawal Phase
This is the critical quality control phase. Once target depth was reached, the drill head was withdrawn at 0.3-0.5 m/min while simultaneously injecting the full design volume of cement slurry, ensuring thorough and uniform mixing along the entire pile length.
Step 4 - Inspection & Field Records
A construction log was completed for every pile, recording: actual depth achieved, total cement volume injected, injection pressure, and elapsed time. Data was reviewed against design requirements immediately at the point of construction.
Pile centres were set out using a total station with positional tolerance ≤ 50 mm. The working platform was compacted to provide a stable surface for CDM rig movement, ensuring pile verticality throughout drilling.
Step 2 - Drill Head Penetration Phase
The D800 drill head was advanced at approximately 25 rpm. Cement slurry injection commenced during penetration to lubricate the auger and initiate early mixing. Penetration rate: 0.5-1.0 m/min depending on soil stratigraphy.
Step 3 - Slurry Injection & Withdrawal Phase
This is the critical quality control phase. Once target depth was reached, the drill head was withdrawn at 0.3-0.5 m/min while simultaneously injecting the full design volume of cement slurry, ensuring thorough and uniform mixing along the entire pile length.
Step 4 - Inspection & Field Records
A construction log was completed for every pile, recording: actual depth achieved, total cement volume injected, injection pressure, and elapsed time. Data was reviewed against design requirements immediately at the point of construction.
Results
• UCS (Unconfined Compressive Strength) average: 0.72 MPa, requirement ≥ 0.5 MPa (44% above design minimum)
• Pile pass rate: 98.7%, non-conforming piles remediated with supplementary treatment
• Quality uniformity (Coefficient of Variation): < 20%, confirming consistent mixing performance across all drill heads
• Load capacity achieved: ≥ 200 kPa - 105% of design specification
• Schedule: Completed on time per contract, zero delay to downstream structural package
• Pile pass rate: 98.7%, non-conforming piles remediated with supplementary treatment
• Quality uniformity (Coefficient of Variation): < 20%, confirming consistent mixing performance across all drill heads
• Load capacity achieved: ≥ 200 kPa - 105% of design specification
• Schedule: Completed on time per contract, zero delay to downstream structural package
Viet Sinh is a Vietnamese manufacturer of CDM drill head equipment, supplying specialist ground improvement machinery to major geotechnical contractors nationwide. With over 18 years of operation and equipment delivered to more than 1,000 infrastructure projects, Viet Sinh brings deep practical knowledge of the real-world demands imposed by each soil type — not just engineering theory.
At Gia Binh Airport, the 30 VKIZAI 90D and 110D drill heads supplied by Viet Sinh accounted for approximately 25–40% of the project's total CDM drilling capacity. This is among the largest aviation infrastructure ground improvement projects in which Viet Sinh equipment has participated to date.
At Gia Binh Airport, the 30 VKIZAI 90D and 110D drill heads supplied by Viet Sinh accounted for approximately 25–40% of the project's total CDM drilling capacity. This is among the largest aviation infrastructure ground improvement projects in which Viet Sinh equipment has participated to date.
Applicable Standards & Quality Control Framework
• TCVN 9393:2012 - Bored piles: construction and acceptance
• TCVN 9351:2012 - Soils for construction: field test methods
• Core sample UCS testing at 3% of piles (random selection) by independent geotechnical laboratory
• Quality Coefficient of Variation (CV) ≤ 20% - meets international uniformity thresholds
Câu hỏi thường gặp
Đầu khoan CDM Việt Sinh có gì khác so với thiết bị nhập khẩu?
Đầu khoan CDM do Việt Sinh sản xuất trong nước, giúp giảm chi phí và thời gian bảo trì so với thiết bị nhập khẩu, đồng thời đảm bảo tương thích tốt với điều kiện thi công tại Việt Nam.
Chính sách bảo hành và hậu mãi của Việt Sinh như thế nào?
Việt Sinh hỗ trợ bảo hành, kiểm tra kỹ thuật, sửa chữa và cung cấp phụ tùng trong quá trình vận hành thiết bị. Nhờ đội ngũ kỹ thuật và hệ thống sản xuất trong nước, các yêu cầu tại công trường có thể được tiếp nhận và xử lý nhanh chóng, giúp khách hàng hạn chế thời gian gián đoạn thi công.
Việt Sinh có thể thiết kế đầu khoan theo yêu cầu riêng không?
Có. Việt Sinh có thể tư vấn và điều chỉnh cấu hình đầu khoan dựa trên máy cơ sở, đường kính cọc, chiều sâu khoan, điều kiện địa chất và yêu cầu thi công của từng dự án. Việc thiết kế cần được đánh giá kỹ thuật trước khi sản xuất để bảo đảm khả năng vận hành và độ an toàn.