<Anchor> The



rain continues to move from region to region, so let’s take a look at what areas have been lacking in preventing flood damage.

Our reporters toured several places at the landslide site in Seoul with experts.



First of all, reporter Park Se-won delivers.



<Reporter>



A huge retaining wall collapsed in the direction of the apartment, and earth and sand struck.



It's been 10 days since a landslide occurred when the retaining wall of an apartment building in Dongjak-gu, Seoul, collapsed due to this heavy rain.



To my right is the Far East Apartment.



To my left is the slope facing the mountain.



A retaining wall has been installed along this slope, but only the central part of the retaining wall has collapsed.



It was designed to drain the valley water from the mountain to the drainage ditch in the center of the retaining wall.



[Lee Su-gon / Former Professor of Civil Engineering, University of Seoul: Water gathers in the valley, so everything is directed to this side (retaining wall).

It's leaning towards the retaining wall and going straight to it.

That's where it exploded.]



Experts say that if the water was designed to drain out in several directions, such as under the retaining wall, major damage could have been prevented.



[Lee Soo-gon / Former Professor of Civil Engineering, University of Seoul: Rain is a facilitator, and the root cause is that drainage facilities were not installed sufficiently to suit this topography and geology.]



Another landslide site.



It was at the back gate of Gyeongmun High School, and as the shaft collapsed, earth and sand poured down and hit all the houses below.



This site also has a structure where rainwater collects on a high ground, but it is presumed that the shaft collapsed due to the lack of drainage passages.



[Lee Su-gon / Former Professor of Civil Engineering, University of Seoul: It is the top part of the ridge, but water is going to collect there.

However, there is not enough drainage system, so water seems to have passed over (toward the shaft) or seeped in.] In



this way, when a residential area is created by cutting a mountain, a retaining wall or pole is erected at the boundary between the mountain and the mountain.



However, if there is insufficient drainage passage or neglect of drainage hole management, it can cause landslides.



[Park Chang-geun/Professor of Civil Engineering, Catholic Kwandong University: If the retaining wall gets old, it gets clogged.

There is soil behind the retaining wall, and then the water pressure will act again.

Then the retaining wall can easily collapse when it gets old.]



Experts agree that the uniform drainage system that does not consider the topography and geology is also a problem.



[Lee Su-gon / Former Professor of Civil Engineering, University of Seoul: I make (drainage facilities) almost identically uniform.

Then, it cannot handle the accumulation of a lot of water, and there (retaining wall) has no choice but to burst.

We have to approach it from a macro perspective...

.]



(Video coverage: Kim Tae-hoon, Video editing: Yoon Tae-ho)