A Movie about SDA

slope supporting self-drilling anchoring
Slope Support by Self-Drilling Anchoring Method

When Self-Drilling Anchor is mentioned in the Movie “The Tunnel”, I know it’s a stroy about Safety.

Most people have seen a tunnel. It is frequently appeared in modern transportation like highway, railway.

Have you ever worried about the safety of tunnel?

The Korean movie “The Tunnel” may give you a nightmare concerning unreliable quality of civil construction.


(Tunnel was collapsing, and Jeong-woo Ha was buried underground.)


Why it happened?

Construction contractor jerry-built the tunnel. The usage of self-drilling anchor was not up to standard.


The modern method to design and construct a tunnel is NATM (New Austrian tunnelling method, also known as SEM).

Its basic principle is taking advantages of  the inherent geological strength available in the surrounding rock mass to stabilize the tunnel. And SDA (Self-drilling anchor, also known as IBO) plays a key role in NATM system.

Function of SDA/IBO hollow bar: Reinforcing + Drilling + Injection

Reliable self-drilling anchor helps to distribute the rock pressure around the tunnel until stabilized by the final concrete structure.

In case of the mountain rock layers move slightly,  SDA rock bolts with good ductility can absorb and transfer the destructive energy. ONTON has posted a diagram to describe energy absorbing.


(Strain-Strss Curve of Self-Drilling Anchor hollow bar)


In the movie “The Tunnel”, Jeong-woo Ha was saved after burying 32 days.

But in reality, chance of survival from such disaster is very low.

As a manufacturer of self-drilling anchor, ONTON hopes all producers supply qualified IBO prodcuts. Don’t ignore ductility performance, don’t let the nightmares come true!