A brief explanation of the New Austrian Tunnel Construction Method and the New Austrian Tunnel Construction Method. The concept of the New Austrian Tunnel Construction Method was proposed by Austrian scholar Professor Rabsiweiss in the 1950s. It is a construction method based on tunnel engineering experience and rock mechanics theory, combining anchors and shotcrete as the main support means. The New Austrian Tunnel Construction Method is generally divided into the following excavation methods according to the wind block conditions of the section and the order of excavation: first, full-section excavation method, second, step method, and third, partial excavation method.
The New Austrian Tunneling Method and the New Austrian Tunnel Construction Method (NATM) are a construction method based on tunnel engineering experience and rock mechanics theory. This concept was proposed by Austrian scholar Professor Rabsiweiss in the 1950s. NATM mainly supports through the combination of anchors and shotcrete, controls the deformation and relaxation of the surrounding rock, makes the surrounding rock an integral part of the support system, and guides the methods and principles of tunnel engineering design and construction through the measurement and monitoring of the surrounding rock and support.
1. The main features of the New Austrian Tunneling Method include:
1. Give full play to the self-bearing capacity of the surrounding rock and minimize the disturbance to the surrounding rock.
2. Carry out initial support in time so that the surrounding rock and support can bear the load together.
3. Implement measurement and monitoring, and adjust the support parameters and construction methods according to the feedback of measurement data.
2. New Austrian Tunneling Method Excavation Method
1. According to the different conditions of the tunnel section and the construction sequence, NATM can be divided into the following main excavation methods:
2. Full-section excavation method: It is suitable for tunnel sections with good surrounding rock stability. The entire section is excavated at one time. The construction speed is fast, but it requires higher surrounding rock conditions.
3. Step method: Divide the tunnel section into two parts, the upper half is excavated first, and then the lower half is excavated. This method is suitable for medium surrounding rock conditions and is conducive to controlling surrounding rock deformation.
4. Partial excavation method: Divide the tunnel section into several parts, and excavate and support them step by step. It is suitable for situations with poor surrounding rock conditions and can better control surrounding rock deformation and construction risks.
III. Advantages of the New Austrian Tunneling Method
The New Austrian Tunneling Method is widely used in various tunnel projects due to its flexibility and strong adaptability. Its main advantages include:
1. Improve the utilization rate of surrounding rock: By rationally utilizing the self-bearing capacity of the surrounding rock, the dependence on the support structure is reduced, thereby saving construction costs.
2. High construction safety: Through real-time monitoring and timely adjustment of construction methods, the surrounding rock deformation can be effectively controlled and construction risks can be reduced.
3. Strong adaptability: According to different surrounding rock conditions and tunnel sections, appropriate excavation methods can be selected to flexibly respond to various complex construction environments.
This construction method has the advantages of flexible construction, strong adaptability, and economic efficiency, and has been widely used in tunnel projects.