Trending claims

Fibers can make concrete more resistant to blasts or impact

Iran is a major producer of concrete and Iranian researchers published papers on concrete mixed with steel fibers

Tuff is a very efficient absorber of energy

Ignimbrite may act to tamp down damaging shock waves

The material probably made it easier to build an underground bunker

Some structures have multiple levels connecting tunnels and hundreds of entrances

Ignimbrite is great to dig into

Ancient subterranean dwellings in Cappadocia were carved into ignimbrite

Iranian survey indicates rock at Fordo consists largely of ignimbrite geologists said

Each shaft opened to trident shape at top according to June 26 Pentagon briefing

Aim was to blow off concrete cap with one bomb drop five more down main shaft

Planners decided they would need multiple bombs

U.S. officials assumed vent zigzagged each bomb expected to hit variable mix of air rock concrete

Shafts zigged and zagged at top path to bunker was not straight until end

Strike planners zeroed in on ventilation shafts to avoid blasting through hard rock above facility

Main shafts did not go straight down Defense Department official said

First blast fractures could allow subsequent bombs to reach deeper how far is hard to predict

Most estimates put Fordo depth between 260 and 360 feet

30000-pound projectile moving faster than sound would travel at most five to 10 meters up to around 35 feet into several common rock types including those at Fordo Ryan Hurley said

30000-pound bomb dropped from B-2 bomber includes more than 5000 pounds of explosives hits ground at supersonic speed before detonating