Manholes – Types, Purpose, Construction & Maintenance

Welcome to the latest edition of our newsletter! In this issue, we will delve into the world of manholes, exploring their types, purpose, construction, and maintenance. Manholes are an essential component of our urban infrastructure, playing a crucial role in ensuring the proper functioning of various utility systems. Let's dive in!

Read more: What is Manholes – Types, Purpose, Construction & Maintenance

What are Manholes?

Manholes are access points to underground utility networks, such as sewage, stormwater drainage, telecommunications, and electrical systems. These vertical structures provide entry and exit points for maintenance, inspections, and repairs. Manholes are typically covered with heavy lids to prevent unauthorized access and ensure safety.

Types of Manholes:

a) Precast Concrete Manholes: These are precast structures manufactured off-site and installed as complete units. They are durable, resistant to corrosion, and offer ease of installation.

b) Brick Manholes: Traditional brick manholes are constructed using bricks and mortar. Although less common nowadays, they can still be found in older infrastructure.

c) Fiberglass Reinforced Plastic (FRP) Manholes: FRP manholes are lightweight, corrosion-resistant, and often used in corrosive environments. They offer a longer service life compared to traditional materials.

d) Cast Iron Manholes: Cast iron manholes are known for their strength and durability. They are commonly used in areas with heavy traffic loads.

Purpose of Manholes:

Manholes serve several important purposes:

• Access for Maintenance: They provide a means for maintenance personnel to enter underground utility systems, ensuring regular inspections, repairs, and cleaning.
• Emergency Access: In the event of emergencies, manholes allow quick access to utility networks for immediate response and repairs.
• Ventilation: Manholes serve as ventilation points, allowing the release of gases that may accumulate within underground systems.
• Monitoring and Sampling: Manholes can be equipped with sensors and sampling points to monitor the condition and quality of utilities.

Construction of Manholes:

The construction process involves several key steps:

• Excavation: A hole is excavated to the required depth and dimensions.
• Base Installation: A concrete base is laid, providing a stable foundation for the manhole.
• Wall Construction: Manhole walls are built using the chosen material, such as precast concrete segments or bricks.
• Connection to Utilities: Utility pipes are connected to the manhole, ensuring the flow of sewage, drainage, or other utility networks.
• Cover Installation: A heavy cover is placed on top of the manhole, ensuring safety and preventing unauthorized access.

Maintenance of Manholes:

Regular maintenance is crucial to ensure the functionality and longevity of manholes. Some maintenance activities include:

• Cleaning: Manholes should be regularly cleaned to remove debris, sediment, and any potential blockages.
• Inspection: Routine inspections help identify structural issues, leaks, or signs of deterioration.
• Repair and Rehabilitation: Any damages or defects discovered during inspections should be promptly repaired or rehabilitated to prevent further deterioration.
• Lid and Lock Maintenance: Manhole lids and locks should be inspected and maintained to ensure proper functioning and prevent unauthorized access.