ae
2-2
on Shot Cactus and from 1160 psi at 1830' to 30.8 psi at 6024' on Shot Koa,
Dynamic pressures data at 3' heishts require further data reduction before
results can be reported.
‘liaximum overpreassures from both shots when scaled
to 1 kt at standard sea level conditions agreed well with 2 1.6 kt free eir
pressure curve.
Neither shot showed any ev.dence of a precursor; in the case
of Koa, this was contrary to predictions. Cactus overpressures show an un=
usually slow and as yet unexplained decay for the first 25-40 msec,
Free-field Ground Accelerations and Rel-tiv: 3:cplacements,.
Instrumentaticn
to measure accelerations at various depths vo 1590! and relative displacement
between the ground surface and the 50 and 1% {o0t depths was installed on
both shots at ranges corresponding to predi:t:d pressures of 600, 200 and-100
psi.
Ground accelerations up to 1120 43 on Xoa amd 616 g on Cactus were ree
corded.
Acceleration wave fcrms wer? nora complex than those obtained at
NTS; wave forms were influenced consideraply by energy transmitted through
the earth from ranges closer to the burst,
higher than expected.
‘iorizontal accelerations were
Peek verticsl @zcelerations showed a more repid decay
with depth than at NTS at similar py ssure icvels.
Relstive displacements
were smaller than observed at Nevada, “arrces*+ being less than 5 inches.
Craters.
Cactus crater dimensions cf 170! radius and 36! depth acreed well
with predictions.
Koa erater duiwnsions of 1025" radius and 160! depth were
significantly larger than predictions; it is believed tne large water tank
surrounding the Koa device may have increased ‘he energy coupling with the
ground.
Simulated Structures.
Twenty two foot. diameter drums, in both horizontal and
vertical orientations, werc buried for bot? shots at verious depths to 20 feet
at the predicted 200 psi pressure range.
Results from the few drums recovered
at this writing and from limited electroni: data availeble indicate soil pres- «(
sure decreased with depth to 1C feet ana tien rose to surface level values at
Car.
Vv (EF
pV
Len iLO/n-
.
_
—s
PAGE /
“