Tunnel building techniques and methodologies

Introduction

Tunnels are a vital part of any underground infrastructure, and they play an important role in everything from transporting goods to serving as emergency escape routes. In this article, we’ll be discussing some of the most common tunnel building techniques and methodologies, so that you can choose the best approach for your particular project.

Types of Tunnel building

The following are types of tunneling:

Shield Tunneling

One of the most common types of tunneling is shield tunneling. This type of tunneling uses a large shield to protect the workers and the equipment from the environment. The shield is made out of materials that are strong enough to withstand the forces of the environment, but flexible enough to deform when hit by objects. This allows the shield to protect the workers and equipment while still allowing them to work.

In this method, a large shield is placed over the opening of the tunnel. The shield is then lowered into the opening and held in place by powerful magnets. This creates an airtight seal around the opening, preventing any debris from entering or exiting the tunnel. This method is used to create tunnels under rivers, canals, and other difficult-to-reach areas.

This is a type of tunneling where the outside environment is protected from the inside environment by a shield. The shield can be made of materials such as earth, metal, or plastic.

Casing Tunneling

Casing tunneling is a type of drilling that uses a special type of drill bit called a casement. The casement bit is inserted into the well through the top of the casing and moves downward as the drill bit cuts through the rock. In this type of tunneling, a pipe is inserted into the ground and then covered with concrete or other material.

There are two types of casing tunneling: directional and non-directional. In directional casing, the drill bit is aimed in a specific direction and the mud is forced out through the hole at a high speed. This type of tunneling is used most often to create tunnels under water. Non-directional casing uses a rotating drum that creates a trench like hole in the ground. The drill bit is then lowered into the hole and the mud is forced out through the hole at a much slower speed. This type of tunneling is used to create tunnels through hard rock or earth.

Drilling Tunneling

There are a few different types of tunneling that can be used for construction purposes. The most common type is drilling, which is used to create tunnels through hard surfaces like rock or concrete. Drilling machines use a rotating drill bit to break through the surface and then create a tunnel below it. This process is usually done in two stages: first, the drill bit is lowered into the ground until it reaches the target area; and then, once the target area is reached, the machine starts drilling.Tunneling techniques can also be used in other environments. For example, boring machines can be used to create tunnels under water. These machines use a special type of drill bit that can swim through the water while still creating a tunnel.

In this type of tunneling, a hole is drilled into the ground and then a pipe is inserted. The pipe is then sealed with concrete or other material. This type of tunneling is used to drill water wells, cable trenches, and other tunnels.

Excavation Tunneling

There are many different types of tunneling, each with its own unique benefits and drawbacks. Excavation tunneling is the most common type of tunneling. It is used to dig tunnels under ground. The main difference between excavation and other tunneling methods is that excavation tunnels are dug using machines called shovels. Excavation tunnels are also wider than other types of tunnels, which makes them easier to build.

Tunnel boring machines (TBM) are the most common type of machine used for excavation tunneling. TBM’s use a rotating drill head to create a hole in the ground. They are usually faster and cheaper than other types of machines, but they can also be more difficult to use. They are also less versatile, meaning they can only be used for excavation tunnels.

This type of tunneling is used to dig tunnels and other holes in the ground. The hole is first dug, and then the pipe is inserted. The pipe is then sealed with concrete or other material. This type of tunneling is used to build tunnels, water wells, and other structures.

Air-Supported Tunneling

Air-supported tunneling is a type of tunneling that uses air pressure to move rocks and earth. It is used to build tunnels under water, in the ground, or in the air. This type of tunneling is often faster and more cost effective than other types of tunneling. Air-supported tunneling machines use several tubes called hangers. The hangers are connected to an air tank and a compressor. The air tank compresses the air, which causes the machine to travel along the tunnel.

In this type of tunneling, a tube is inserted into the ground and then air is pumped into the tube. The air creates a pressure inside the tube that pulls the pipe through the ground. This type of tunneling is used to build tunnels, water wells, and other structures.

tunnel building techniques
Tunnel building techniques

The Five Basic Tunnel Building Techniques

There are many ways to build tunnels. However, the five most common tunnel construction techniques are tunnel boring machines (TBM), hand-dug tunnels, submersible tunneling methods, suspended-tube tunneling methods, and cut-and-cover tunneling methods. Each technique has its own strengths and weaknesses. The five basic tunnel building techniques are as follows:

  1. Tunnel boring machines (TBM): TBM is the most common type of tunnel construction technique because it is the most efficient and uses the least amount of resources. TBM is a machine that cuts through the Earth’s surface using a rotating cutter head. The machine can go through rock as hard as granite. The downside of TBM is that it can be expensive to build and maintain and it can take a long time to reach a desired destination.
  2. Hand dug tunnels: Hand dug tunnels are typically used when destination are close to the surface or when digging is not an option due to terrain restrictions. Hand dug tunnels can be more economical than TBM, but they require more manpower and time to complete. They can also be more dangerous because they are less stable and can collapse more easily.
  3. Submersible tunnel methods: Submersible tunnel methods are used when a destination is below the surface. The machine uses a watertight tunneling capsule that is lowered into the ground by a cable. The capsule then follows the tunnel valve until it reaches the desired destination. The advantage of using submersible tunnel methods is that they are safe and can move faster than other tunnel construction techniques. However, they can also be more expensive and difficult to maintain than other methods.
  4. Suspended-tube tunneling methods: Suspended-tube tunneling methods are used when a destination is deep underground or in difficult to access terrain. The machine uses a series of tubes that are suspended from the ground by cables. The tubes are then lowered into the ground until they reach the desired location. This technique is less expensive than other methods, but it can be more difficult to install and maintain because it requires special equipment and skills.
  5. Cut-and-cover tunneling methods: Cut-and-cover tunneling methods are used when a destination is aboveground but adjacent to an obstacle, such as a river or mountain range. The machine excavates a small hole in the obstacle and then builds a roof over the hole. Once the roof is completed,the machine cuts through the obstacle and enters the desired location. This method is less expensive than other methods, but it can be more time consuming and difficult to install.

Methodologies for Tunnel building

tunnel construction is an inherently complex and challenging process, which is why there are many different methodologies and techniques to choose from. Here are a few of the most popular:

  • Conversation Tunnel Method (CTM): This is a staged approach to tunnel construction in which the excavation is first completed in an open trench before being filled with concrete and continuously reinforced with steel bars. The CTM provides the most consistent tunnel quality and requires the least amount of excavation, making it the most cost-effective option.
  • Blind Tunnel Method (BTM): Also known as a “pontoon” method, this approach involves excavating a large open trench before beginning to build the tunnel under it. The BTM allows for a more flexible design and is less expensive than the CTM, but it also results in a poorer quality tunnel.
  • Munter Tunnelling Method (MTM): This approach uses a series of chambers or “tunnels” that are connected by shafts. The MTM allows for quick construction and better flexibility in design, but it can be more expensive than other methods.
  • Tunnel Boring Machine (TBM): The TBM is the most common tunnel construction machine and is used to excavate tunnels and create underground access. It is also capable of creating a variety of other features, such as shafts, chambers, and channels.
  • Cordless Tunneling Machine (CTM): The CTM is a specialized tunnel construction machine that uses electric power to move the machines and equipment through the tunnel. This machine is quieter and easier to operate than traditional tunnel construction machines, making it ideal for certain applications.
  • Subsurface Electric Tunneling Machine (SETM): The SETM is a specialized tunnel construction machine that uses an electric current to move the machines and equipment through the tunnel. This machine is less expensive than traditional tunnel construction machines, but it is not as quiet or flexible.
  • In-Place Tunnelling Method (IPTM): The IPTM is a specialized tunnel construction method that uses an explosive to break through the surface and create the tunnel. This method is less expensive than other methods, but it can result in extensive damage to the surrounding area.
  • Pipe Tunnel Method (PTM): The PTM is a specialized tunnel building method that uses PVC pipes to move the machines and equipment through the tunnel. This method is less expensive than other methods, but it can be difficult to install and maintain.
  • Vertical Tunnel Method (VT): The VT is a specialized tunnel building method that uses an elevator to move the machines and equipment through the tunnel. This method is less expensive than other methods, but it can be difficult to install and maintain.
  • In-Situ Inspection (ISI): ISI is a technique used to inspect the tunnel building project before it begins. This method uses special cameras and sensors to capture detailed images of the tunnel environment and construction progress.

Evaluation of tunneling building techniques

Tunnel construction techniques and methodologies have been evaluated to determine their effectiveness for specific tunnel applications. Five tunnel building techniques were evaluated: drilled shaft, cut and cover, bored tunnel, precast concrete frame tunnel, and tunneling shield. The evaluated techniques were utilized to construct a 1.5-km long tunnel under a major road in Singapore. The objective of the study was to compare the performance of the five techniques using cost, time, and safety parameters.

The results of the study showed that a bored tunnel was the most efficient technique for constructing tunnels with low drag due to its large diameter and relatively short construction time. It was also found to be the most cost-effective technique, as it required the lowest amount of earth removal and provided the best safety parameter due to its low risk of encountering live underground utilities. A precast concrete frame tunnel was found to be less efficient than a bored tunnel, requiring more earth removal and longer construction time. Cut and cover were found to be the least effective technique, requiring more earth removal but a shorter construction time.

The study showed that a bored tunnel was the most efficient technique for constructing tunnels with low drag due to its large diameter and relatively short construction time. It was also found to be the most cost-effective technique, as it required the lowest amount of earth removal and provided the best safety parameter due to its low risk of encountering live underground utilities. A precast concrete frame tunnel was found to be less efficient than a bored tunnel, requiring more earth removal and longer construction time. Cut and cover were found to be the least effective technique, requiring more earth removal but a shorter construction time.

Protective Measures Against Dust Explosions

Dust explosions are a serious safety hazard in tunnel construction. In order to minimize the chance of an explosion, tunnel builders must take a number of precautions.

Here are some tips to protect yourself and your crew:

  • Keep the area around the tunnel clean and free of debris. This will help prevent dust from becoming airborne and forming into an explosive mixture.
  • Avoid working near any dangling wires or cables. If they become tangled or caught in machinery, they could create sparks that could ignite dust particles and create an explosion.
  • Make sure all tools and equipment are properly grounded to avoid electrical shock hazards. Sparks can ignite dust particles and create an explosive mixture.
  • Wear adequate protective clothing, including a face mask and gloves. Dust explosions can cause severe injuries if inhaled or contact with high levels of dust occurs.

Managing the Tunnel Restoration Process

If you are restoring a tunnel, it is important to have a plan and methodologies in place. This will help you manage the restoration process and ensure that your tunnel is restored to its original condition. There are many different techniques and methodologies for tunnel restoration, so it is important to choose the one that best suits your specific situation. Here are some tips for choosing a tunnel restoration technique:

  • Determine the purpose of the tunnel. If it is a vehicular or pedestrian tunnel, the restoration process will be different.
  • Consider the age and condition of the tunnel. Old tunnels may require more maintenance than newer tunnels, so be sure to factor this into your decision.
  • Consider the environment surrounding the tunnel. If it is in an urban area, consider how traffic will affect the restoration process.
  • Assess the resources available to you. If you are restoring a small tunnel, you may be able to do it yourself using volunteer labor or guerrilla tactics. If you are restoring a large or historic tunnel, however, hiring an expert contractor may be necessary.

Once you have chosen a restoration technique, begin planning your restoration project accordingly. Keep in mind that every tunnel

Conclusion

In this article, we will be discussing different tunnel building techniques and methodologies that can be used for a variety of purposes. From military tunnels to undersea tunnels, there is a technique that can be used for nearly any type of tunnel project. By understanding the different methods and applying them to your own specific tunnel construction project, you can ensure successful completion.

tunnel building techniques
Tunnel building techniques

FAQs on tunnel building techniques

How do you dig a tunnel without it collapsing?

There are many ways to dig a tunnel without it collapsing. One way is to use an excavator. The excavator digs a large hole in the ground and then pushes the dirt and rocks out of the hole. This method is usually used for large tunnels, such as those for highways or railroads.
Another way to dig a tunnel is using a tunnelling shield. The shield is a large metal box that is attached to the front of a bulldozer or excavator. The bulldozer or excavator digs down into the ground, and the shield follows behind it. The shield helps support the weight of the bulldozer or excavator, so it doesn’t collapse the tunnel while it’s being dug.

What is meant by tunneling in construction?

Tunneling is a technique used in construction to create a tunnel under a surface. The most common use of tunneling is in the construction of roads, railways, and other infrastructure. Tunnels are often built through soft soil or mud, which can be difficult to dig through using traditional methods. Tunneling techniques allow for the construction of tunnels much faster and with less disruption than traditional methods.

What keeps a tunnel from collapsing?

Tunnels are often built in difficult and dangerous environments. They are often built under rivers, through mountains, or through other tunnels. One of the main factors that keep a tunnel from collapsing is the weight of the rocks above it. If the rocks are too heavy, they will push down on the tunnel and eventually collapse it. Tunnels are also built with strong foundations to keep them stable.
To keep the walls from collapsing, engineers use a number of techniques. One common method is to use steel beams to support the walls. These beams are connected to the walls by concrete pillars, which help keep the walls from moving. Engineers also use large amounts of sand and gravel to create a stable foundation for the tunnel.

Tunnel building techniques