Slurry wall

Civil engineering technique From Wikipedia, the free encyclopedia

A diaphragm wall is a continuous, vertical wall of reinforced concrete that is used to support excavations or to retain soil. It is typically constructed by excavating a trench and then pouring concrete into the trench. The concrete is reinforced with steel bars to provide strength and rigidity.

Diaphragm walls were first developed in the early 20th century. They were originally used in Europe to support excavations for subways and other underground structures. In the United States, diaphragm walls were first used in the 1950s. They have since become a common construction method for a variety of projects, including deep basements, tunnels and retaining walls.

History

The development of diaphragm wall technology in Europe began at the beginning of the 1950s with the work of Christian Veder and Hans Lorenz.[1] The advantages of this special civil engineering method quickly became apparent in the construction of inner-city excavation pits and infra-structural measures in the form of low-deformation, water-impermeable reinforced concrete walls, as well as in the use of sealing walls in earth dam and landfill construction.

The earliest recorded use of diaphragm wall technology is said to be during the excavations for the construction of the Milan Metro in Italy back in the 1950s.[2]

Construction Process

The process of constructing diaphragm walls involves several steps. First, the correct position and alignment of the diaphragm wall are established using surveying techniques and marking it on the ground. Temporary guide walls are then built on both sides of the planned excavation area to ensure accurate trenching and support during diaphragm wall construction. Trenching is then carried out using a hydraulic grab or clamshell bucket attached to a crane. The trench is kept full of slurry to prevent it from collapsing. Reinforcement cages are then lowered into the trench and concrete is placed using tremie pipes. Once the concrete has set, the slurry is removed and the anchors are installed. Their step-by-step procedure can be as follows:

Excavation: A trench is excavated to the required depth. The width of the trench will depend on the thickness of the wall and the type of soil.



Formwork: A formwork is constructed in the trench to hold the concrete in place while it is curing. The formwork can be made of wood, steel, or concrete.

Reinforcement: Steel bars are placed in the formwork to reinforce the concrete. The spacing of the bars will depend on the load that the wall will be subjected to.


Concrete Pouring: Concrete is poured into the formwork and allowed to cure. The concrete is typically vibrated to remove any air bubbles. Concrete pouring for diaphragm wall construction

Backfilling: Once the concrete has cured, the trench is backfilled. The backfill material should be compacted to prevent the wall from moving.


Applications

Diaphragm walls have a wide range of applications in construction. They are commonly used in deep basements, tunnels and other underground structures where space is limited and excavation needs to be carried out close to existing structures. They can also be used as retaining walls for embankments and cuttings.

  • Deep basements: Diaphragm walls are often used to support deep basements. They can also be used to create watertight basements.


  • Tunnels: Diaphragm walls are used to support tunnels. They can also be used to prevent soil from collapsing into the tunnel.


  • Retaining walls: Diaphragm walls can be used to retain soil. They are often used to create retaining walls along highways and other infrastructure.


  • Foundations: Diaphragm walls can be used as foundations for buildings and other structures. They can provide a strong and stable foundation in difficult soil conditions.

Advantages

Diaphragm walls offer several advantages over other construction methods such as piling. They can be installed in close proximity to existing structures without causing damage. They also provide a watertight barrier that can withstand high water pressure. They are very strong and can support large loads. They are watertight, which makes them ideal for basements and tunnels. They can be constructed in difficult soil conditions. They are relatively quick and easy to construct. They can be used to create a variety of shapes and sizes.

Limitations

One of the main limitations of diaphragm walls is their cost. They can be expensive to construct. They are more expensive than other construction methods such as piling. They also require specialised equipment and skilled labour. Construction may get disruptive to surrounding properties. They require specialised equipment and expertise to construct.

Notable Projects

Several notable projects have used diaphragm walls, including the construction of the Burj Khalifa in Dubai, which is currently the tallest building in the world. The project involved constructing a 50-metre-deep basement using diaphragm walls.

The Channel Tunnel: The Channel Tunnel is a 31-mile-long tunnel that connects England and France. It is supported by a diaphragm wall that is over 200 feet deep.


The Chicago Deep Tunnel: The Chicago Deep Tunnel is a network of tunnels that is used to collect and divert stormwater. It is supported by a diaphragm wall that is over 100 feet deep.


Diaphragm walls are a versatile and effective construction method that can be used for a variety of applications. They are strong, watertight and can be constructed in difficult soil conditions. However, they can be expensive to construct and require specialised equipment and expertise.

Loading related searches...

Wikiwand - on

Seamless Wikipedia browsing. On steroids.