eee Rt Oe eee e ans Mile dieltpdiehitiien boii iL de a os mad OPTITae TPT ¥ HATE Sadibd bcdtela ‘ sats, aha’ Mal d sini’ pik hla vin’ oe cry : te aoeitle Ar iieatin dardsLetnedeal WBE tn diel toting bait CHAPTER 4 CONCLUSIONS The follow:mg conclusions can be drawn from the damage survey performed for Operation Ivy, 1. The damage auntatned by the various buildings of Structure 3.1.1 due to shot Mike was as follows: The test panel= of Buildings i and 7 sustained only slight additional damage due to air hlast. The steel frames of Building 2 suffered moderate plastic daformation, and the steel sheeting of the rear face wae distorted inward between girts. The steei C(rame and aiding of Building 6 received io apparent additional damage. The concrete frames of Buildings 3 and § suffered moderaiz clastic defurmation. The rear wail cf Building 5 was blown off by the sir blast. The shear walls of Building 4 were undamaged. However, 'arge cracks were opened in the rocf slabs adjacent to the shear walls and roof girders. The overpressure wa3 approximately 14 pa, 2. Structure 3.1.3 suffered no major structural damage, ‘fle biast Joors were removed prior tu the test, The wood frame air lock, which was left in places, was destroyed by the air blast. The painted surface of the vent pipe was charred on the side facing Grourd Zero. The Kaye overpressure was approximately 18 pyi. 3. All reiaforced-concrete seniburied instrumentation shelters apogearad to Lave parlurmed their function satiafaciorily without exhibiting any peimary structural failures, 4, Of the many cre- story reinforced-concrete eurface ind seribuvini ytructures chaerved, none were badly danage2. The only ser:ous structural fadures onwervec were confined to wing walls designed to retain portions of the {ili on the semiburiec structures exposed sicel beams and pipes attached tc these structures were damaged and aes!trayed by overprossuren of Tltne ns, and greater, Terme Stadia ihialh KK a: Trap eee sa . isinachdcibbeacbattledy ilsshies Ait te ay oe ees 5. Small buildings covered with thie sheet mota: over 2) .coaa] wuud eheathing penerclly withstood overpressures up to 5 ana 6 pst. However, one vicuctui's of this type wae observed badly damaged by an overpressure of 4.5 pai. 6, Lightly constructed wood frame shacks apparently sneathed with covcugaiee metal and located in regions with overprac. .res yreater than 4 ps: wer? completely desizeyed. No ctructures of this type were observeo 1. regions subjected tn less than 4 pg) overpressure. %. Palm trees were destroyed by air-biast overpressures uf 4 to S psi. J grecter, but none were destroyed by overpressures less than 4 psi. From the resuiis of the dynamic analysis of Struct; 4 3.1.0 presentcd in Sec. 2.6, the fn lowing conclusions car be drawn: 1. The frec-air overpressure existing in the vicimity of Structure 3.1.1 for shot Mike ot Operation Ivy was between 12 ard 14 psi. 2. Pressures measured by the side-on Laifle gaze at Station 611-01 on Engebi were more reliable than those measured by the Pitot-static tube page at the same stztion. 3. The vifect on structural response of rise times of the order uf magnitude investigated ig small, 121-122 SECRET - RESTRICTED DATA