RAE Tyg SECRET CHAPTER1 INTRODUCTION é. general damage survey of all structures of interest at Eniwetok was made ia August 1953 by T. O. Stark of the Office of the Chief of Engineers and John S. Archer of the Massachusetts inatituie uf Technoiogy. Excespts from a letter report on this field trip written py olark are included as Apper<ux A of ‘his report. The pertinent cata snd pncnographs obtained in the field survey are includes in Thap. 2 and Appendix B for Structvre 3.1.1 and in Chap. 3 for all other structures. A general darmsse survey of all structures other than 3.1.1 at the site was mare with the intention of correiact-.4 overpreasures with observed structural damage. Photogi*rhic evidence of the dama.c c3 Cbtained whenever possible, and detailed measuremeats were m4aue ci the damage where an cis:ysis of the structural behavior appeared practisel. 1.3 HISTORY With the excertion of Structures 3 1.1 and 3.1.3, practically all buildings ocgerved at the site were constructed for the suppost of Operation Ivy. Structures 3.1.1 and 3.1.3 .cre cum- pleted in 1951 os test etructures uncer the sponsorship of the Office of the Chief of F-aincers, Department of the Army, for Creratic . Greenhouse. During the Greenhouse operation Structure $.1.1 was subjected to 2 peak refiected air-blaat overpreasure of about 30 pai as a result of shot Easy, the structures test shot. Following an extensive damage surve> the structure was again subjected to an air biast from snot Item but froin a different dir ction, A leas extensive damage survey was made after this si.ct since the ortentation of the tiast wave was such that the air blaet caused leas damage than shot Easy to the frames cf the test structure A program of electronic inetrumentation of Structure 3.1.1 waa propused by the Office of the Chief cf Engineers tor Operation Ivy but waa not approved on the basig that this operation SECRET RESTRICTED DATA Treble ee 1.2 SCOPE 1 reerrertmmeminerer: meventee 7 ERT RE EE te eUapreMmeIeeTE emene putt ATEenonome peraptie tp The purpose ©! thia report is to (1) record and interpret the results of the damage result~ ing from shots King anu Mike of Operation Ivy at Entwetok on a number of miscellancous structures includ!:w, tne Greenhouse Army Test Structure 3.1.1 and (2) to prezeat a dynamic analysia of Str. c1u:e 3.1.1 to determine the probable loading and establish correiation with meagured blast prrsaures in the region near Structure 3.1.1. nee emEE RN eS tt Oe CO IRRTE 1.1 PURPOSE