CHAPTER 2

DAMAGE SURVEY AND ANALYSIS OF STRUCTURE 3.1.)
2.1

GENERAL

Structure 3.1.1, the Greenouse Army Test Building, was the only structure examined at
the site of Operation Ivy which had Leen constructed for the exclusive purpose of measuring
the effect cf air blast from nuclear weapons on surface structures. This structure hapr aed to
be located at a rangs from Ground Zero of shot Mike® of Operation Ivy such that the damege

caused by the air blast wag witsis iimits suitable for a dynamic analysis. In addition, complete
plang were availaole for ‘'e structure, and damage survey notes were availabie for the previous
nuctear shots which had damaged the structure.
The magnitude of tne air-blast wave for shot Mike of Operation Ivy at the location of
Structure 3.1.1 was not known rellably, although a number of measurements cf air-blast overpressures were made at various disiances {rom Ground Zero.’ Therefore an estimateof the
actual air-blast pressure at Structure $.1.1 can best be <btained by aynamic analyses of
Buildings 2 and 3 of this at.ucture. Various levels of air-biast overpressure are assumed,
and the response is computed using methods of analysis which have been developed.'3-' A
comparison of the computed response for the various asau.ned leve._ of :.iz-Llast overpressure
with the actual values of permanent deflection measured in the fiela survey !24ds to an estimate of the proucble atr-blast overpressure at the locaticn of Siructure 3.1.1.
The field survey measurements and photographa of Structure 3.1.1 are presented in Sec.
2.2. The ¢ynamic analyses of Srildings 2 and 3 are presented in Sec 2.2.

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SECRET~ RESTRICTED DATA

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*Shot King ofOverction Ivy produced air blast overpressurea at Structure 3.1.1 of sucha
low magnitude thet no measurable damage occurred from this shot.

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made by a representative of the Office of t1.o Chief of Engineera in the fall of 1952.
A description of the post-lvy damage survey and resulta is presented in the following
sections.

i Sh iad oe

obtained foiiowing shota Easy and Item of Operation Greenhouse’ard com the pretest visit

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The image survey measurements made afie, Operation Ivy consisted in exterior-walloffset measurements, colums-<ffsct nwasurementa, and icof-elevation measurement. In addition, general cbservatious ani photographs were made of the utructure which :. shown diagrammatically in Fig. 2.1, Since no bench marks or fixed soints were available upon which to
base the measurements, only relat! e horizontal and vertical displacements of the structure
were obtainec.
The pre-Ivy condition of Structure 3.1.1 was determined {rom survey notes and phtugrachs

TT

SURVEY MEASUREMENTS AND RESULTS

i

2.2

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