THE DAMAGE TO STRUCTURES CAUSED BY SECOND MIYAKOJIMA TYPHOON. Author(s) ISHIZAKI, Hatsuo; KATSURA, Junji; M.

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Disaster Prevention 18(1): 1-14 Issue Date 1968-05 URL http://hdl.handle.

1 Title THE DAMAGE TO STRUCTURES CAUSED BY SECOND MIYAKOJIMA TYPHOON Author(s) ISHIZAKI, Hatsuo; KATSURA, Junji; M Citation Bulletin of the Disaster Prevention 18(1): 1-14 Issue Date URL Right Type Departmental Bulletin Paper Textversion publisher Kyoto University

2 Bull. Divas. Prey. Res. Inst., Kyoto Univ., Vol. 18, Part 1, No. 130, May THE DAMAGE TO STRUCTURES CAUSED BY THE SECOND MIYAKOJIMA TYPHOON by Hatsuo ISHIZAKI, Junji KATSURA and Tatsuo MUROTA (Manuscript received May 8, 1968) Abstract From 5th to 6th September 1966, the Second Miyakojima Typhoon (6618, Cora) struck the Sakijima Islands, Okinawa, and moved northwest along the south coast of Miyakojima Island as slowly as 10 km/h bringing a severe wind force never experienced before. The damage to structures caused by this typhoon was severest in Miyakojima and in the northeast area of Ishigakijima. In Miyakojima the rate of damaged houses was around 50%, although most of them were wooden structures. I. Introduction A severe wind storm caused by the Second Miyakojima Typhoon struck the Sakijima Islands, Okinawa, from 5th to 6th September 1966, and devastated most towns in Miyakojima and the northeast area of Ishigakijima. The damage was severest in Miyakojima, where the rate of completely destroyed houses was as high as The authors investigated the damage caused by this typhoon in Miyakojima and Ishigakijima Islands in October This paper reports on the damage to structures according to the investigation. 2. General wind pattern of the typhoon The general wind pattern of the Second Miyakojima Typhoon is described in detail in another paper. 1) We shall now make a brief comment on it. From 5th to 6th September 1966, this intense typhoon passed northwestward over the Sakijima Islands. The eye wall of the typhoon moved as slowly as 10 km/h along the south coast of miyakojima, where a severe storm with a wind speed of more than 40 m/s lasted for about 13 hours. The maximum wind speed of 60.8 m/s (NE) (06h31m, Sept.5), the maximum peak gust of 85.3 m/s (NE) (07h31m, Sept. 5 ) and the minimum atmospheric pressure of mb were observed at the Miyako Weather Station, Miyakojima Island. 3. Types of buildings in Okinawa Several typhoons with severe wind storms attack the Okinawa area every year. The expected maximum wind speed in Miyakojima for example is 67 m/s every 100 years, 46 m/s every 10 years and 30 m/s every 2 years. 2) In these circumstances buildings in Okinawa are usually designed so as to resist the force of a wind of more than 68 m/s at 10 m above ground. 3) Most of the buildings in Okinawa are wooden hip-roofed ones with tile roofings, which are divided into two types; clay tile roofings and cement tile roofings. (Photo. 1, Fig. 1) 4. Definition of terms and notations In order to describe the extent of the damage to buildings, we shall use several terms here following the definitions below:-

3 2 H. ISHIZAKI, J. KATSURA and T. MUROTA ' completely destroyed: damaged by wind to the extent that the expense of repairs is more than 70% of the total construction cost badly damaged: damaged by wind <fre" m to the extenthat the expense of. repairs is more than 30% of the 'total construction cost - - rate of completely destroyed houses: ratio of the number of completely destroyed houses to the total number rate of badly damaged houses : ratio of the number of badly damaged houses to the total number _ ' rate of damaged houses : sum of the two rates defined above 51/4404 ' 1Notations qte;,,,40-a'11 /it total number of houses, Ne = number of completely destroyed houses Photo. 1 Two types of roofings of wooden Nb= number of badly damaged buildings in Okinawa : houses (a) ing. clay-tile roofing, (b) cement-tile roof- R e=rate of completely destroyed houses =Ne/Ne Rd = rate of damaged houses= (Ne+NO/Nt plaster soil / clay tile V..; cement tile mortar IN IIX1 rafterorimme^. bed board rafter Fig. 1 Two types of roof sections of wooden buildings in Okinawa. (a) clay-tile roofing, (b) cement-tile roofing. 5. Brief view of the damage The Second Miyakojima Typhoon brought about severe damage to the Sakijima Isls, where most of the damage was caused by the force of the wind, not by the flood. The damaged buildings were mainly wooden buildings, but steel structures were also damaged. Reinforced concrete buildings were only partly damaged.

4 The Damage to Structures Caused by the Second Miyakojima Typhoon 3 Table I shows the number of damaged houses in Miyakojima and Ishigakijima by administrative districts, which is illustrated in Fig. 2 in the case of Miyakojima. Table 1 Damage to houses caused by Typhoon 6618 by administrative districts. DISTRICTli Nt Nc NbICIRCM) Rb(96) MIYAKOJIMA ISLANDS HIRARA CITY GUSUKUBE-CHO SHIMOJI-CHO 980 i UENO-MURA TOTAL I11060 IC L 1 ISHIGAKIJIMA ISLANDS ISHIGAKI CITY it: badly Ns...,.. awir completely destroyed damaged C.) 2000 houses 0 Slcm I _ HIRARA \ 0 e eashimoji ) visor, i i i \, C.\ --; GUSUKUEE \. l i UENO 0.) ICl k Fig. 2 Damage to houses by administrative districts in Miyakojima.

5 4 H. ISHIZAKI, J. KATSURA and T. 111UROTA Table 2 Damage to houses in communities on Miyakojima. COMMUNITY 1 NtNC Ns R96IeRei 11 COMMUNITY 1 NtNo'Nn 1R IRd 96'96,96 HIRARA CITY CITY ZONE MIYAHARA , KOSHIBARU TAKA NO FUNAKOSHI SOEDO KUGAI SHIMOKAWA MATSUBARA NISHIHARA NANABARU , FUKUYAMA SHINTOYO /1 OURA CHIMORI SHIMAJIRI , YAMANAKA KARIMATA NOBARUGOSHI OGAMI MORIKA IKEMAE HOSOTAKE TOTAL GUSUKUBE-CHO BORA HIK A YOSHINO NAGAKITA ] 45.5 NANA MATA NAGANAKA 105' MINAFUKU NAGAMINA , ARAGUSUKU YOSHIDA , FUKUHIGASHI NISHINISHI FUKUNAKA NISHINAKA FUKUNISHI SHIMOKITA FUKUMINAMIj SHIMOMINAMI I 31.7 FUKUKITA SUNAGAWA NISHIHIGASHI TOMORI NAKAHARA 61 [ KAJIDO TOTAL k SHIMOJI-CHO KURIMA KATEKARI YONAHA TAKACHIHO UEJI KAWAMITSU SUGAMA L IRIE '; TOTAL i UENO-MURA UENO TAKATA NAKAYAMA TOYOHARA , MIYAGUNI NOBARU OMINE CHIYODA SHINZATO TOTAL

$.\ The Damage to Structures Caused by the Second Miyakojima Typhoon 5 The damage in Miyakojima was quite extensive, but in Ishigakijima on the other hand the damage was confined to the northeast area$ . point of which is 108 m above the..---'-`-1:71;,;;;:4,t`r,(l.7-f --- :,4 sea. Trees and forests grow spar-*-,?.--.:4c4,44::..4..444--..4, 4,...40,;.

. point of which is 108 m above the..---'-`-1:71;,;;;:4,t`r,(l.7-f --- :,4 sea. Trees and forests grow spar-*-,?.--.:4c4,44::..4..444--..4, 4,...40,;.

6 .\ The Damage to Structures Caused by the Second Miyakojima Typhoon 5 The damage in Miyakojima was quite extensive, but in Ishigakijima on the other hand the damage was confined to the northeast area and was minor in other regions. 6. Distribution of damage in Miyakojima Island Miyakojima is a flat Island about 180 km2 in area, the highest :->Attrri :- s----;;;;11.r.": ;7,.,,..;.*.. point of which is 108 m above the..---'-`-1:71;,;;;:4,t`r,(l.7-f --- :,4 sea. Trees and forests grow spar-*-,?.--.:4c4,44:: , 4,...40,;.-nratoope, sely and most parts of the islandare covered by sugar cane fields, kr.--a ,44w44 so Miyakojima is unduly exposed -.4,:t is,-::: : to the force of the wind. (Photo. 3) Table 2 and Fig.3 show the rate of Photo.2 Typical Miyakojima landscape. damaged houses in communities on Miyakojima. In some communities 60% of the houses were completely destroyed and 90% were damaged. As averages the C& I 10 II 1 INEHAE 15N. 22 YAMANAKA SHIMOWIA 15V.. OGAMI KAWART5U NAGAM1N4M1 21 KAllinte7A MONANA NAGAKI74 32 SMIMAMIN II 25 UEN NAGANMA 32 Height alma Ow ma OURS U04M A 11, Illte S_I411 SIOMOKAY/A FLUIMMA NISHN m N1SNIMARA TAKACHINO N46 A 18 FUKUYAMA KAOEGAP ligkahara E NISHIHIGASIII 27 ' D it2le et tertpletelymama 5 35 MIYAGUN FUKUMINAM1 41 destroyod houses 10 all 6 32 LIEN KAMM 24 funak05141 MAGI 56 33CNIVOL1/ I24 ''<4 MATSUMRA TOVOHARA FUKUKITA CHIMORI36 NAKAYAMA UKUN4KA 56 AIMS 09 melts arm the tote35 07 NANABARU DONNE 0 o 00.. NIG* 27 MOPIKA35 56FUIWINGASNI 59ARAGUSUKU TAKADA35 numbers 50 01hOLI8OSin MO 200 locabliosfi AKANO Ni/ MINANUKU SUNAGAWA 7 61tallAMA NO8ARUGOSMI MONI RA 36 N vi LI YOSHIND 23..g i\a 0 Mt.,fral.eaat wiagra-wa --rils=wp----r-a.:=--1, Z._My--.--=-1..4t. --7 rratṭ1 -a f60*, s 23 "e Si. - =. ' tvw eari.m.---,itw-w:ãt 2._W--_---- r=filiatsittriabaati--l kji-sitrrszerat-- I tre.. sorl--._.e r-r.r. SCALE 0 S km Fig. 3 Rate of completely destroyed houses in communities on Miyakojima.

7 6 H. ISHIZAKI, J. KATSURA and T. MUROTA rates of completely destroyed and damaged houses were 17.6% and 48.7% respectively. Such a high rate of damage seems to be because of the open nature of the island and the lack of trees to break the force of the wind. 7. Distribution of damage in Isbigakijima Island Table 3 and Fig. 4 show the damage to houses in communities on Ishigakijima. The damage is confined to the communites on the northeast peninsula and is minor in other regions. So the average rates of completely destroyed and damaged houses are very small compared with Miyakojima, being 0.9% and 2.6% respectively, This is considered to be mainly due to the relatively long distance from the center of the typhoon and also to the wind-shelter effect of the topography. In fact the maximum wind speed of 27.3 m/s and the maximum peak gust of 44.9 m/s observed at the south coast of Ishigakijima are about half those in Miyakojima. Table 3 Damage to houses in communities on Ishigakijima. COMMUNITY I Ne No Nn R%e9Rd6COMMUNITY 1 NoNaNn1R0 Rd % 96 TONOSHIRO OF 0.3 MIYARA 285 ol ' OKAWA SHIRAHO ISHIGAKI ISOBE SHINKAWA KAWAHARA , 0 NAGURA MIWA , 76.5 TAKEDA KAINAN MOTONAGURA OMOTO SAKIEDA OSATO KABIRA NOSH INO OTAKE INODA ,10 L 9 NAKASUJI ONO YOSHIHARA IBARUMA YONEHARA NOSOKO TOMI NO AKASHI OTA KUURA ITONA YOSHINO MAESATO HIRAKUBO HIRATOKU HIRANO OHAMA TOTAL

$a The Damage to Structures Caused by the Second Miyakojima Typhoon 7 IMAM "Ur Ay 72% Height at.. the In =SIM\,os) oto203310 CO %Om0 4.$ $4 OcJ so so 2O0 <00% IN 'N MOIRA 0cyr YONERARA 4 osmium IA o 113..11NO IRA 21% aikinv:cak...in vofr, SMIE 7477. \V A, \a ''Hosoleo AI\ n't H " \ %,,*- a.$ 4 Rate of damaged houses in communities on lshigakijima. 8.

4 Rate of damaged houses in communities on lshigakijima. 8.

8 a The Damage to Structures Caused by the Second Miyakojima Typhoon 7 IMAM "Ur Ay 72% Height at.. the In =SIM\,os) oto CO %Om0 4.4 Rate ofcompletelydeetrged and tattydamageelhousetit all MASH, %- Y)!SARUM ***** ofciicifshoo,theto NOSOKO 9x `17 o 0 00ooon1/4.4 OcJ so so 2O0 <00% IN 'N MOIRA 0cyr YONERARA 4 osmium IA o NO IRA 21% aikinv:cak...in vofr, SMIE \V A, \a ''Hosoleo AI\ n't H " \ %,,*- a.4 :4; 0 4 YLNACK amom 02ATO NAGSWAO":,0 126% 0A SCALE (CXEDA 111WA ismem, An- k SHIRAHO OHIRATOMU 0IYVAA 910E km Fig. 4 Rate of damaged houses in communities on lshigakijima. 8. Distribution of damage in the city Table 4 shows the damage to houses in 21 communities in the city zone of Hirara City, Miyakojima, excluding the rural districts. In the city zone the rate of completely destroyed houses of 5,1% is 1/3 of the average value of 16.7 % in Miyakojima. Table 4 is illustrated in Fig. 5, indicating that the damage in the windward communities was severer than in the downwind ones.

9 - 8 H. ISHIZAKI, J. KATSURA and 7'. MUROTA Table 4 Damage to houses in the city zone of Hirara City. COMMUNITY NiNe1Nb 1R 1 COMMUNITY Ni196 NOR%Rd 96 MINAMINISHIZATO DEGUHI KAMIYA AZUMA OMITAWARA '! SAKAE 13112: MAEPIYA NAKAYA 20619, UEZUNO i ASAHI OHARA TAKAARA HARIMIZU ' HIGASHIKAWANE KITANISHIZATO NAKAHOYA , NEMA : HOSATO SHIMOYA NIKAWATORI HADATE TOTAL / s.... f'd l al\ fei--... sie.:::.::::maw/wore a a ale- NAKAHOYA _ ii -----ni w..., ii:iiiiii:iiiiiii; 1 KETANISHISATO,7, a...- ti '"HAMM -1.6 a-,.minaminish/sato--- f8_, s Cif/... /1 9:2C/He,Tt.0 i ir." g--11_,..,0---i r-1 NENs.91, ASAHI 5.4 a IINIIYA,--, 4,--OMITAWARA-1-5Galur7.0, i _.,,,.,AKA l... it illimmig=1:12 III HIGASHITCAVNE 0-3.0% r 4_, HADATEini 8.1 ^-1'UE=0-=mann,_DEGUCHI565, --.I =;-2.7-L ,=MIME ABM a 0 ^ P I,MI1,Mal 21/, rt I 1 SAKAE,:6.1-9.o % OHAHR7MIMI 1_163, /10.11AP Fig. 5 Zoning map of completely destroyed houses in Hirara City ,0 % - / I 4 s

The Damage to Structures Caused by the Second Miyakojima Typhoon 9 9.

Reinforced concrete buildings. Reinforced con-,,

mostly broken doors and windows. (Photo. 3),. y- Wooden buildings.

of roofings:-0.,, Fr -.gm '.... :it,'.:,,...., ';'la 1es.

$buildings; a broken,- - (a). # y.t.. -..---,....,,.1.,,' '\%''''''CAtt.,. oa, :! t t?-r.$ s.,t.m.fisti.f41-;,,a -...:.-1,,Ths----- -1t-4''2'.*"%%:%".4.i%gf...V"C-- -s.4n''"-t;-.

111 ' 4 '' i' - h 0% h"'"---:- t' P:* ' ' --h. -,, h,4. i,.

10 The Damage to Structures Caused by the Second Miyakojima Typhoon 9 9. Structural types of damage 4,! Reinforced concrete buildings. Reinforced con-,,.,.,.. - crete buildings of schools, offices, dwellings were only partly damaged; mostly broken doors and windows. (Photo. 3),. y- Wooden buildings. The damage to wooden buildings appeared to differ in feature according Map to the type of roofings:-0.,, Fr -.gm '.... :it,'.:,,...., ';'la 1es.''I1j ger 411'111" -h 4 '' i,i - I,0, IF,ir,,-, : '1 r f.: A i i. w 01;141511tar.E7.2 Photo. 3 Damage to reinforced.*---- '' y>..0*,.:-',concrete.door. buildings; a broken,- - (a). # y.t ,....,,.1.,,' '\%''''''CAtt.,. oa, :! t t?-r.s.,t.m.fisti.f41-;,,a -...:.-1,,Ths t-4''2'.*"%%:%".4.i%gf...V"C-- -s.4n''"-t;-.-: , :it..k.ti.o...-, 4...tivi.-.4,1,r.-:i.;=2;-:crowe,_ -.N.:--r _ ' 4 '' i' - h 0% h"'"---:- t' P:* ' ' --h. -,, h,4. i,. 1-1,"1", ' 0-t41:: t pitrit,,, low -. - e.., (b) (c) %.--.-,,.. ir,,, _ ,.,...,._.,....,, ,...,1/4..( ' MICR (d) (e) Photo. 4 Damage to wooden buildings with clay-tile roofings ; (a) wreckage of openings, (b), (c) removal of tiles from ridges and corners, (d) removal of tiles from the eave, (e) total destruction of a school building. (by courtesy of the Miyako Bureauof Local Administration --(a), (b), Hirara City Hall= (c), and The Okinawa Times=(e)).

destruction (2) damage to wooden buildings with cement-tile roofing without bed boards were as follows :

-t- "vti, ' '',, ',.: --" i - - -.ter' t :,,,.,,,, rvi t -jar (a) 4'4:114 iirta4 a!. if q' r - (b) :,.

!..At--A-,*---48.0.:'"'--:.'4-ej,i.:3:'C:- +r-.' tc. ---."imyttlit.=-c: +3 7".t4..le ' lc ' ik V, (c) -.

5 Damage to wooden building with cement-tile roofing : 47 /='r' (a) lifting of tiles from a leeward roof,

11 10 H. ISHIZAKI, J, KATSURA and T. MUROTA (1) damage to wooden buildings with clay- or cement-tile roofings with bed boards were as follows: (Photo. 4) 0 broken doors and windows ii) removal of roof tiles from eaves, ridges, verges or corners iii) total destruction (2) damage to wooden buildings with cement-tile roofing without bed boards were as follows : (Photo. 5) c,;,..,..-./...,:-.-2-.r--- iatz4--t. 7? e.,:i& _..,.2 :::.,.t. ;; /4-1, j ' ''''247"/".-t- "vti, ' '',, ',.: --" i ter' t :,,,.,,,, rvi t -jar (a) 4'4:114 iirta4 a!. if q' r - (b) :,..r - t-,,: -'si".--"''. -6ir -4- dry : "4.?.. 17:4 bilibil.,,a.1:'''<'''-e-,-'., ".. *0''''C't.!..At--A-,* :'"'--:.'4-ej,i.:3:'C:- +r-.' tc. ---."imyttlit.=-c: +3 7".t4..le ' lc ' ik V, (c) -...-,,4 an -"... 4 (e) *,,S").e 4;.,.. *Aiet"' r'a,, "..//,. a Phhto. 5 Damage to wooden building with cement-tile roofing : 47 /='r' (a) lifting of tiles from a leeward roof, (b) removal of tiles from eave, (c) (d) removal of tiles from leeward roofs, (e) total destruction of a P.,,.,/ i.i.,, - -- _114.. house. (by courtesy of Hirara City Hall=(b), the -',:.-A./2`4' Miyako Bureau of Local Administration = (c), the, 7U. and S. The Civil Okinawa Administration Times = of (e)). the Ryulcyus - (d) -3- '-'-' "t[,,,ip' (d). -

The Damage to Structures Caused by the Second Mayakojima Typhoon 11 i) broken doors and windows ii) lifting of tiles from leeward roofs iii)

openings in the walls. Steel frames. Damage to steel framed buildings occurred in sugar factories and a warehouse of the 1111/41, - '" -s-- U.

.4410 "'4fi4to ilk many galvanized iron plates were _ iik)c-"ct,/ removed from the walls or roofs. Om'ie.)4,1.

6) Reinforced masonry buildings with wooden roofs. Masonry buil- it',z..-4.

4,,,. moval of wooden roofs, because of the weak connection between roofs 0- and walls. (Photo.7). Towers and similar structueres.

The damage was generally not so serious, which indicate that proper structural design keeps them safe against the orce of winds of 60 m/s.

12 The Damage to Structures Caused by the Second Mayakojima Typhoon 11 i) broken doors and windows ii) lifting of tiles from leeward roofs iii) removal of tiles from leeward roofs, eaves or verges iv) total destruction The lifting and removal of tiles are closely related with damage to openings in the walls. Steel frames. Damage to steel framed buildings occurred in sugar factories and a warehouse of the 1111/41, - '" -s-- U.2 r.ele.s. Army, The sugar factories' "..SC% / were galvanized iron structures and "'4fi4to ilk many galvanized iron plates were _ iik)c-"ct,/ removed from the walls or roofs. Om'ie.)4,1..see The warehouse was a gable-roofed x 11.' steel frame and collapsed completely(a) downwind. (Photo. 6) Reinforced masonry buildings with wooden roofs. Masonry buil- it',z..-4. dings were not so much in number r as wooden buildings but most of4f4au i' them were seriously damaged. The damage was mostly the bodily re-,. 4,,,. moval of wooden roofs, because of the weak connection between roofs 0- and walls. (Photo.7). Towers and similar structueres. Table 5 shows the damage to towers and similar structures. The damage was generally not so serious, which indicate that proper structural design keeps them safe against the orce of winds of 60 m/s. (b) Photo. 6 Damage to steel framed structures: (a) collapseof a gable-roofed warehouse, (b) collapse of a track crane at a sugar factory (by courtesy of the U. S. Civil Administration of the Ryukyus= (a) and the f Miyako Bureau of Local Administration ie I tr.." A'S " Mil ik3-1,* r, alp --,. itrari ".^- t (a) (b) Photo. 7 Damage to masonry buildings with wooden roofs : (a), (b) bodily removal of roofs (by courtesy of The Ryukyu Shimpo (a)).

12 H. ISHIZAKI, J, KATSURA and T. MUROTA Table 5 Damage to towers and similar structures in Miyakojima.

top of a hill, slip-off of a guy cable, reinforced Hirara City cracks in the windward concrete, side of the pile (Photo. 9) G. L.

5m/sec (Photo. 11) p 4(.4 f t) Photo. 8 Damage to a steel truss antenna : separation of paint by wind. 1/4"*.Afile., 97: Photo.

13 12 H. ISHIZAKI, J, KATSURA and T. MUROTA Table 5 Damage to towers and similar structures in Miyakojima. TYPE SITE DAMAGE antenna steel truss, in flat, sugar-cane separation of paint by wind G. L. +35m I field, Hirara City (Photo. 8) guyed pile. top of a hill, slip-off of a guy cable, reinforced Hirara City cracks in the windward concrete, side of the pile (Photo. 9) G. L. +12m chimney reinforced in a sugar factory, no damage (Photo. 10) flag mast concrete and steel, G. L. +20m Shimoji steel pipe, 900, top of a hill. displacement of the top G. L. +11m Hirara City about 30cm leeward; estimated wind speed is 60.5m/sec (Photo. 11) p 4(.4 f t) Photo. 8 Damage to a steel truss antenna : separation of paint by wind. 1/4"*.Afile., 97: Photo. 9 Damage to a reinforced concrete antenna cracks in the windward side. 10. Conclusions From the investigation of the Second Miyakojima Typhoon (6618, Cora) the following results are obtained:- (1) The maximum wind speed observed in Miyakojima was 60.8 m/s and the rates of completely destroyed and damaged houses were 17.5 % and 48.7 % respectively in Miyakojima.

The Damage to Structure:. Caused by the Second Miyako Jima Typhoon 13 t Itter,"*" "10 -=.. ' Illbs -stia±47,,at rr7,411111111angli. e11y11-1-4r1'1, 44;44,4" '1-3'4."7114 Photo. 10 Stacks in a Photo.

9 % and 2.656 respectively, which seems to be mainly due to the relatively long distance from the center of the typhoon and also to the windshelter effect of the topography.

(4) The damage to wooden buildings was as follows:- The damage to walls appeared to occur at openings, which was closely related to the removal of roof tiles in the case of roofings without bed

(5) Reinforced concrete buildings or tower structures only suffered local damage.

14 The Damage to Structure:. Caused by the Second Miyako Jima Typhoon 13 t Itter,"*" "10 -=.. ' Illbs -stia±47,,at rr7, angli. e11y11-1-4r1'1, 44;44,4" '1-3'4."7114 Photo. 10 Stacks in a Photo. 11 Damage to a flag sugar factory : no damage. mast : displacement of the top about 30cm leeward. (2) In Ishigakijima the rates of completely destroyed and damaged houses were as small as O. 9 % and respectively, which seems to be mainly due to the relatively long distance from the center of the typhoon and also to the windshelter effect of the topography. (3) In the city zone of Hirara City the damage rate was smaller than in the rural districts, and the windward area in the city was more seriously damaged than the leeward. (4) The damage to wooden buildings was as follows:- The damage to walls appeared to occur at openings, which was closely related to the removal of roof tiles in the case of roofings without bed boards. The damage to tiled roofs appeared to occur on eaves, ridges, verges or corners, and was extensive in the case of roofings without bed boards. (5) Reinforced concrete buildings or tower structures only suffered local damage. Acknowledgements The authors desire to convey their thanks to the many residents of the region affected by the disturbance, for their assistance in supplying information at a time of great stress. Also to Mr. Tokumatsu Maeshiro, Mayor of Hirara City, who afforded facilities for the investigation, and to the Government of the Ryukyus and local administration offices in Miyakojima and Ishigakijima for their cooperation in supplying information. In addition, thanks are due to the following organizations, who supplied photographs of the devastated region; the U.S. Civil Administration of the Ryukyus, the Miyako Bureau of Local Administration, Hirara City Hall, Ishigaki City Hall, Hirara Fire Department, The Ryukyu Shimpo and The Okinawa Times.

15 14 H. ISHIZAKI, J. KATSURA and T. MUROTA References 1) Y. Mitsuta and S. Yoshizumi, Characteristics of the Second Miyakojima Typhoon, Bulletin of the Disaster Prevention Research Institute, Kyoto Univ., vol. 18, Part 1, ) Y. Mitsuta, K. Miyata and S. Yoshizumi, Severe Wind Storm Caused by the Second Miyakojima Typhoon, Annuals, Disaster Prevention Research Institute, Kyoto Univ., No. 11A, (in Japanese) 3) Building Code for Use in Okinawa, Wind Load.

Makoto Watabe Professor of Environment and Information, Keio University, 'L-25-5 Tokiwadai Itabashi-Ku, Tokyo, Japan

Kobe Earthquake Makoto Watabe Professor of Environment and Information, Keio University, 'L-25-5 Tokiwadai Itabashi-Ku, Tokyo, Japan Abstract This paper is about the Kobe earthquake in Japan which happened