Derek Newsome @DerekdotSpace: "Saw some concern earlier about SLC-6s flame trench holding up to Falcon Heavy due to Delta IV Heavy having significantly less thrust, I'd like to put that to rest."

SLC-6 is a launch pad at Vandenberg Space Force Base.

Summary: because "SLC-6's main trench was designed to handle >30,000 kN of thrust", the thrust of a Space Shuttle. "Falcon Heavy makes ~22,800 kN of thrust".