Introduction to the OMR Construction Method
The OMR (Large Diameter Rotary Drilled and Bell-Bottomed Pile) method is a cutting-edge construction technology that utilizes full hydraulic computer-monitored expansion to create deep foundation piles. This technique offers a maximum expansion ratio of up to 2.2 times the pile diameter. It uses a rotary drilling rig for hole formation, with a fully hydraulic cutting and excavation process. After excavation of the shaft, a two-stage hydraulic bell-bottom grab bucket is employed for horizontal cutting. The entire process is managed and monitored using a computer-controlled system, which provides real-time data and images of the pile’s base depth, bell-bottom dimensions, and shape. This innovative approach allows for precise and high-quality construction that meets or exceeds design requirements.
The OMR method significantly increases the load-bearing capacity and uplift resistance of single piles, offering a safe and efficient solution for foundation construction. With an expansion ratio of up to 2.2 times, this method represents the most advanced bell-bottom construction technology in China. The OMR method was introduced from Japan and has since become a highly sought-after solution due to its exceptional performance and reliability.
Key Features and Advantages of the OMR Method
1. Advanced Hydraulic Technology
The OMR method utilizes a fully hydraulic bell-bottom grab bucket, equipped with sensors to monitor the expansion process. The entire operation is controlled through a computer monitoring system, allowing for visual and precise adjustments throughout the process. The expansion is performed in two steps: first, a sloped bottom is created, followed by a vertical expansion. This reduces the cutting resistance, enabling the use of smaller equipment and ensuring a smoother operation.
2. Improved Construction Speed and Quality
Compared to traditional bell-bottom pile methods, the OMR technique offers significantly faster hole formation and expansion. The use of a rotary drilling rig speeds up the process, while the hydraulic system ensures minimal noise and vibration, contributing to a safer and quieter working environment. Additionally, the original soil is removed efficiently, reducing environmental pollution.
3. High Load-Bearing Capacity
The OMR method enables the creation of piles with larger diameters and greater load-bearing capacity. The shaft diameter can reach up to 3000mm, and the bell-bottom diameter can go up to 4700mm, with an expansion ratio of 2.2 times and a bell-bottom rate of 4.9 times. The maximum depth of the pile can reach 80 meters, making this method ideal for high-rise buildings and other large-scale construction projects.
4. Cost Efficiency and Environmental Benefits
By using the OMR method, contractors can achieve significant cost savings. The bell-bottom expansion doubles the load-bearing capacity compared to piles with the same shaft diameter and depth, reducing the need for concrete by more than 25%. Furthermore, the OMR method minimizes environmental impact by eliminating the need for slurry and reducing noise and vibration levels, which makes it a more sustainable choice for modern construction projects.
Construction Process and Technology
1. Drilling and Expansion Process
The OMR method begins with the formation of a hole using a rotary drilling rig. Once the hole is drilled to the required depth, the hydraulic bell-bottom grab bucket is used for expansion. The expansion is carried out in two stages: the first stage involves creating a sloped bottom, while the second stage completes the vertical expansion. The expansion is controlled and monitored using a computer system, ensuring the dimensions and shape of the pile’s base meet design specifications.
2. Hole Cleaning and Waste Removal
The OMR method includes an innovative SCS (Slurry Cleaning System) designed to clear the hole efficiently. A special, sensitive device is used to insert a submerged slurry pump into the hole, ensuring rapid cleaning of debris. The cleaning system ensures that the remaining debris is minimized to less than 5cm, even in very large pile diameters, ensuring the pile’s integrity.
3. Visual Monitoring and Quality Control
A key feature of the OMR method is its visual monitoring and quality control system. The entire process is tracked by a computer system, allowing operators to monitor the pile formation and expansion in real time. This provides a high level of precision and ensures that the pile meets the required specifications, improving the overall quality of the construction.
Advantages of the OMR Method
-
Higher Load-Bearing Capacity and Uplift Resistance: The OMR method results in piles with significantly higher load-bearing capacity and resistance to uplift compared to traditional methods.
-
Fast Construction and Low Environmental Impact: The OMR method is faster and more efficient, with minimal environmental impact, as it eliminates noise, vibration, and slurry.
-
Cost Savings: The OMR method reduces the amount of concrete needed, leading to cost savings of up to 25%.
-
Adaptability to Different Geologies: The OMR method can be used for a wide range of soil types, making it suitable for various construction projects.
Conclusion: The Future of Foundation Construction with OMR
As urban infrastructure development continues to evolve, the demand for large, deep foundation piles is increasing. The OMR method, with its advanced technology and ability to provide superior load-bearing capacity, has become an essential solution for modern construction projects. Whether for high-rise buildings, bridges, or other large-scale developments, the OMR method offers an efficient, cost-effective, and environmentally friendly solution that meets the highest industry standards.
With its rapid construction speed, high-quality results, and minimal environmental impact, the OMR method is poised to become the preferred choice for foundation construction in cities like Beijing, Shanghai, and Tianjin, where underground space development is a key focus of urban planning.
By adopting the OMR method, contractors can enhance the performance and durability of their foundations while ensuring compliance with modern environmental and economic standards.
