A_RadiusThrust
From ZDoom Wiki
A_RadiusThrust (int thrust, int radius, bool hurtshooter)
A_RadiusThrust makes an object "Blow" enemies nearby away from them. Thrust is how powerful the wind is (It is as powerful as what an explosive would be based on damage), Radius is how far around the object should the effect be (If you set it to 64, then if anything comes with 64 units, it is blown away) and hurtshooter specifies whether the user of the projectile/object gets affected. If this is 0, they are not affected. If it's 1, then they are.
A_RadiusThrust is like A_Explode without the damage.
Examples
The following example shows a projectile that blows objects away with a power of 128 within a 64 unit radius without affecting the shooter:
actor WindyProjectile
{
height 4
radius 2
PROJECTILE
states
{
Spawn:
WIND ABCDEFGHIJK 2 A_RadiusThrust (128, 64, 0)
WIND LMNO 2
stop
}
}

