1. Background of technology development

The size of underground manholes of electric power and telecommunication companies is increasing according to the policy of undergrounding electricity and communication facilities, and in addition, maintenance costs are increasing to solve the flooding problem that occurs every year due to the inflow of rainwater. There is an urgent need for countermeasures. Problems caused by inundation of the underground manhole are as follows.

1) Maintenance of underground manhole inspection costs such as pumping, internal cleaning, and diagnosis costs

2) When the underground manhole is flooded for a long time, the durability of the underground facility decreases and the lifespan is shortened.

3) Delayed emergency recovery work in case of cable failure in flooded manhole

4) Increasing safety risks such as safety accidents

2. Product principle

It is an underground manhole delayed drainage device that simultaneously drains rainwater flowing into the soil by utilizing the principle of permeable concrete and blocks backflow when the groundwater level rises.

(Excellent inflow ⇒ Increase in natural pressure ⇒ Check valve open ⇒ Permeable concrete passage ⇒ Flow rate decrease ⇒ Rainfall delayed drainage ⇒ Absorbed into the ground soil below the manhole ⇒ Check valve shut off when reverse flow) 

3. Product features

1) Excellent strength and durability.
It is easy to replace and maintain the check valve and sludge filter.
Applied to ensure structural safety.

2) Excellent drainage persistence.
The continuous pores are formed organically so that the water permeability is excellent, and the water permeability is excellent even after contamination by sludge.

3) Ensure the safety of the soil ground.
As a double pore structure, through the delayed drainage effect that relieves water permeability
It secures the safety of the soil and ground by preventing sinkholes.

4) Block backflow of groundwater.
The water flowing into the manhole is blocked by the rise of the groundwater level through the check valve for preventing backflow.

5) Easy to install and maintain.
It can be simply installed in new/existing manholes without changing the structure,
It is easy to replace and maintain the check valve and sludge filter.​

1. Background of technology development

The size of underground manholes of electric power and telecommunication companies is increasing according to the policy of undergrounding electricity and communication facilities, and in addition, maintenance costs are increasing to solve the flooding problem that occurs every year due to the inflow of rainwater. There is an urgent need for countermeasures. Problems caused by inundation of the underground manhole are as follows.

1) Maintenance of underground manhole inspection costs such as pumping, internal cleaning, and diagnosis costs

2) When the underground manhole is flooded for a long time, the durability of the underground facility decreases and the lifespan is shortened.

3) Delayed emergency recovery work in case of cable failure in flooded manhole

4) Increasing safety risks such as safety accidents

2. Product principle

It is an underground manhole delayed drainage device that simultaneously drains rainwater flowing into the soil by utilizing the principle of permeable concrete and blocks backflow when the groundwater level rises.

(Excellent inflow ⇒ Increase in natural pressure ⇒ Check valve open ⇒ Permeable concrete passage ⇒ Flow rate decrease ⇒ Rainfall delayed drainage ⇒ Absorbed into the ground soil below the manhole ⇒ Check valve shut off when reverse flow) 

3. Product features

1) Excellent strength and durability.
It is easy to replace and maintain the check valve and sludge filter.
Applied to ensure structural safety.

2) Excellent drainage persistence.
The continuous pores are formed organically so that the water permeability is excellent, and the water permeability is excellent even after contamination by sludge.

3) Ensure the safety of the soil ground.
As a double pore structure, through the delayed drainage effect that relieves water permeability
It secures the safety of the soil and ground by preventing sinkholes.

4) Block backflow of groundwater.
The water flowing into the manhole is blocked by the rise of the groundwater level through the check valve for preventing backflow.

5) Easy to install and maintain.
It can be simply installed in new/existing manholes without changing the structure,
It is easy to replace and maintain the check valve and sludge filter.​