Here is the full list of all 8 Enemy Trench achievements.
Complete chapter 1 and start the 11th level
Complete Chapter 2 and start the 21st Level
Complete Chapter 3 and start the epilogue
Succeed a composure check
Fail a dex check on a mud tile and get stuck
Complete the first Level without taking a hit from an enemy
Have 1 of each of the 5 ranged weapon types in your inventory.
Survive a grenade explosion when the player is in the danger zone