Deen dangerous on many occasions at sawmill or paper factories. Horikawa 

 I1961) has stressed consideration of appropriate measures for anchoring 

 stacked timber at such tsunami-endangered places; the writers strongly 

 support this view. 



In general, the type of land structure that can hest survive tsunami 

 inundation is one of sound reinforced-concrete construction with deeply 

 embedded foundations or solid raft foundation (foundation mats) capable 

 Df resisting scour. Shear walls are desirable. Orientation of structures 

 LS important in that long axes are directed toward the sea and parallel 

 :he path of attack so that minimum areas of resistance are exposed to 

 ^aves. Well-constructed, timber-frame buildings, firmly secured to ade- 

 quate deep-set foundations, may be considered for areas on the lee side 

 3f a belt of more solid buildings which could break the impact of debris, 

 food- frame structures, however, should be strongly braced both vertically 

 md horizontally at floor and ceiling levels. It may be desirable in 

 :ertain circumstances to design structures with substantial framing but 

 fith expendable ground-floor walling. Upper floors in such buildings 

 tTould generally be immune to wave and water damage; ground-floor damage 

 TOuld be considered tolerable (cf. Matlock, et al, 1962; Wiegel, 1965; 

 4agoon, 1965; Reese and Matlock, 1967). 



■ k. Harbor Structures : Their Damage and Protection 



The docks in the areas that suffered substantial tsunami damage 

 ^ere all of timber construction with the exception of the sheet-pile 

 railroad docks in Seward, which were damaged by slides. 



The old Cargo Dock at the Kodiak Naval Station was completely 

 iestroyed, basically because of inadequate connections between piles and 

 the deck, but also because extracted piles failed to return to the augered 

 pile-holes in the rocky bottom. A moored ship raised the bollards during 

 bsunami-induced motions, and probably also caused damage while slamming 

 against the dock. 



The Marginal Pier of the Naval Station suffered minor damage, mainly 

 from a moored barge which loosened a bollard and some decking. This 

 lock, paradoxically, had to be loaded down with heavy chains after the 

 earthquake so it would not float away during later high tides, which sub- 

 sequently reached a higher level because of land subsidence. The Tanker 

 and Tender Pier of the Naval Station was not critically damaged. 



At Crescent City, California, the Citizens Dock was damaged mainly 

 by a moored timber barge that slammed against the dock. Much repair work 

 was needed on corbels, decking and fenders on this dock. The approach 

 pier to Citizens Dock was heavily damaged when the deck was buoyed by 

 the tsunami waves. The majority of the supporting pilings which were en- 

 cased in a concrete wave barrier under the dock snapped when this barrier 

 was exposed to high lateral forces resulting from different water levels 

 on the two sides of the barrier. 



367 



