Metro Diaphragm Wall Construction in India: An Overview

What is diaphragm wall construction, and why is it used in Metro projects?

Diaphragm wall construction is used to construct deep excavations, such as those required for metro rail projects. It involves the installation of a continuous wall made of concrete, which is created by excavating a trench and then filling it with concrete while supporting the surrounding soil using bentonite or polymer slurry. Diaphragm walls are typically used as retaining structures to support the soil and prevent water seepage and are often used in metro projects to create underground stations, tunnels, and other facilities. They are instrumental in urban areas where space is limited, as they allow for deep excavation without affecting the surrounding buildings or infrastructure.

Metro Diaphragm Wall Construction in India: Challenges and Solutions

Metro diaphragm wall construction in India presents several challenges, including difficult soil conditions, a high water table, and limited space for equipment and materials. However, several solutions have been developed to overcome these challenges.

One such solution is using polymer slurry instead of bentonite, which allows for faster excavation and reduces groundwater contamination risk. Additionally, specialized equipment such as hydro mills and cranes with extended reaches is used to overcome space constraints.

Case Study: Delhi Metro Diaphragm Wall Construction

The Delhi Metro is one of India's most extensive metro systems, with a network of over 390 km. Diaphragm wall construction was used extensively in the construction of the system, particularly in the construction of underground stations.

In the construction of the Delhi Metro, diaphragm walls are used to create underground stations and support tunnels and other structures. The use of diaphragm walls allowed for deep excavation without affecting the surrounding buildings or infrastructure and helped to prevent water seepage into the excavated area.

Benefits of Diaphragm Wall Construction for Metro Projects

Diaphragm wall construction offers several benefits for metro projects, including:

1. Reduced disruption to surrounding infrastructure: Diaphragm walls are ideal for urban areas where space is limited, as they allow for deep excavation without affecting the surrounding buildings or infrastructure.

2. Increased safety: Diaphragm walls provide a stable and secure retaining structure, reducing the risk of accidents or collapse.

3. Enhanced durability: Diaphragm walls are made of high-quality concrete designed to last several decades, providing a durable and long-lasting solution for metro construction.

4. Improved efficiency: Diaphragm walls can be installed quickly and efficiently, reducing the project's overall construction time and costs.

Conclusion

Diaphragm wall construction is a vital technique in constructing metro rail projects in India. Despite the challenges presented by difficult soil conditions, high water tables, and limited space, innovative solutions have been developed to overcome these challenges. Diaphragm walls offer several benefits, including reduced disruption to surrounding infrastructure, increased safety, enhanced durability, and improved efficiency.