ESTIMATION OF UNDERGROUND STRUCTURE IN SHIZUKUISHI BASIN BASED ON THE MICROTREMOR MEASUREMENTS AND ANALYSIS
ᄢⷺᕡ㓶*䊶ਛ㩷 **
Tsuneo OHSUMI㩷and Susumu NAKAMURA
The Northern Iwate Prefecture earthquake happened at September 3,1998 and has a similar characteristics with The 1999 CHI-CHI earthquake, Taiwan. First of all, the damages such as slope failures around epicentral region and the failure of underground structures due to the vertical dislocation of ground caused by the fault movement are described. Furthermore, the strong motion records were observed around the epicentral region. The maximum acceleration is more than 700gal. The characteristics of the seismic records were influenced by the fault mechanism as dip slip. Hereby, in this work, estimation of underground structure based on the microtremor measurements and analysis were conducted in Shizukuishi basin so as to examine the effectiveness of approach.
㩷Key Words䋺㩷 㩷 1998 Northern Iwate Prefecture earthquake,㩷 seismic damages, seismic records, SPAC method, kinematic source model
㪈㪅㩷㩷䈲䈛䉄䈮㩷
1998ᐕ 9 3ᣣ䈮⊒↢䈚䈢ጤᚻ⋵ർㇱ㔡䈲䇮ᭂ㔡Ḯ
ၞㄭற䈪㔡ᐲ6ᒙ䉕⸥㍳䈚䇮1999ᐕ921ᣣ䈮บḧ䈪⊒
↢ 䈚䈢㓸 㓸 㔡 䈫ห ᭽ 䈮ૐ ⷺ ㅒ ᢿ ጀ 䉕㔡 Ḯ ᯏ ᭴ 䈫䈚䇮 㕙䈮ᢿጀ䈱ᓇ㗀䈫⠨䈋䉌䉏䉎ᲑᏅ䈱⊒↢1)╬䈱․ᓽ䉕䈚䈩 䈇䉎䇯บḧ䊶㓸㓸㔡䈪䈲ᢿ ጀㄭற䈪䈱ᒝ 㔡⸥㍳䈮㕙 ᵄ 䈱ᓇ㗀䈫⠨䈋䉌䉏䉎㐳ᦼᚑಽ䈱ථ䈏䉄䉌䉏䇮ᢿጀ䉋䉍 20km ⒟ᐲ㔌䉏䈢บਛ᷼䈮䈍䈔䉎♧Ᵽ䉺䊮䉪䈱䉴䊨䉾䉲䊮䉫 䈮䉋䉎ⵍኂ䉕䉅䈢䉌䈚䈢䈫ផቯ䈘䉏䈩䈇䉎 2)䇯ጤᚻ⋵ർㇱ㔡 䈮䈍䈇䈩䉅䇮㔡Ḯ䉋䉍⚂10km㔌䉏䈢㔑⍹⋆ౝ䈪䈱᷹ⷰ⸥
㍳䈮㕙ᵄ䈱ᓇ㗀䈫ផቯ䈘䉏䉎ᵄ⟲䈏䉄䉌䉏䈩䈇䉎䇯䈖䈱
᭽䈮䇮ጤᚻ⋵ർㇱ㔡䈲㔡ⷙᮨ䈲⇣䈭䉎䉅䈱䈱㓸㓸㔡 䈫㘃ૃ䈱․ᓽ䉕䈚䈩䈇䉎䇯䈖䈱䈖䈫䈎䉌䇮㔑⍹⋆䈮䈍䈇䈩 䈠䈱᭽䈭ᵄേ䈱⊒↢䊶વᯏ᭴䉕ᛠី䈜䉎䈖䈫䈲䇮ᓟ㔡Ḯ ᢿጀㄭற䈮䈍䈔䉎ฦ⒳᭴ㅧ‛䈱⠴㔡⸳⸘䉕ⴕ䈉䈢䉄䈮ᔅⷐ 䈭 ജ 㔡 േ 䉕 ⹏ ଔ 䈜 䉎 䈪 ㊀ ⷐ 䈪 䈅䉎䈫 ⠨ 䈋䉌䉏 䉎䇯৻
ᣇ 䇮㔑 ⍹⋆ 䈪ⷰ ᷹䈘䉏䈢 㔡 ⸥㍳ 䈱⊒↢ 䊶વ ᯏ᭴䉕ᛠ
ី䈜䉎䈢䉄䈮䈲䇮᷹ⷰὐ䉕䉃㔑⍹⋆䈱⋚᭴ㅧ䈏ᔅ ⷐ䈫䈭䉎䈏䇮․䈮ᷓጀ⋚᭴ㅧ䈱⚦䈭䊂䊷䉺䈲ᓧ䉌䉏䈩䈇 䈭䈇䇯
䈖䈖䈪䈲䇮㔑⍹⋆䈮䈍䈔䉎ᷓጀ⋚䉕ᛠី䈜䉎䈢䉄䇮Ᏹ
ᤨ ᓸ േ ᷹ⷰ 䉕ታ ᣉ 䈚䇮䈠䈱⚿ ᨐ 䈮ၮ 䈨䈐ផ ቯ 䈚䈢⋚᭴ ㅧ 䈮䈧䈇䈩ႎ๔䉕ⴕ䈉䇯⋚᭴ㅧ䈲 2ὐหᤨ᷹ⷰ䈮䉋䉍᳞䉄䈢
ⓨ 㑆 ⥄ Ꮖ ⋧ 㑐 㑐 ᢙ 䈮ၮ 䈨䈒 ⋧ ㅦ ᐲ ․ ᕈ 䉋䉍ផ ቯ 䈚䈢䇯૬
䉒䈞䈩䇮㔑⍹⋆䈱᧲ᣇะ䈱⋚᭴ㅧ䉕ᛠី䈜䉎䈢䉄䇮1 ὐ᷹ⷰ䉕12ὐ䈪ታᣉ䈚䈢䇯
㪉㪅㩷㩷㔑⍹⋆䈮䈍䈔䉎㔡േ․ᕈ㩷
㔡 Ḯ ㄭ ற 䈱 Nagayama(JMA)䇮Shizukuishi(JMA)䇮䈘 䉌䈮K-net䈮䉋䉎㔡Ḯᣇ䈱↰ᴛḓ Tazawako(K-net)䇮㔡 Ḯ᧲ධᣇะ䈱⋓ጟᏒ Morioka(K-net)䈱4ὐ䈪᷹ⷰ䈘䉏 䈢ᒝ㔡⸥㍳䈱᳓ᐔ 2 ᚑಽ䉋䉍᳞䉄䈢䊔䉪䊃䊦䊐䊷䊥䉣䉴䊕䉪䊃 䊦 2)䈱 Ყ セ 䉕࿑ 䋭 㪈 䈮 ␜ 䈜 䇯 䈖 䉏 䉋 䉍 䇮 㔡 Ḯ ㄭ ற 䈱 Nagayama(JMA)䈪䈲 3.4Hz䇮1.7Hz䈮ථᵄᢙ䈏䉄 䉌䉏䉎䈏䇮৻ᣇ䇮Sizukuishi(JMA)䈪䈲 0.4Hz ㄭற䈪ૐ
ᵄᢙᏪၞ䈮ථᵄᢙ䈏䉂䉌䉏䇮䈖䈱ᵄᢙᏪၞ䈱䉴䊕䉪䊃
*㩷 ਛᄩ⎇ⓥᚲ㩷✚วᛛⴚ㐿⊒ㇱ
** ᣣᧄᄢቇ㩷 Ꮏቇㇱ㩷 ᧁᎿቇ⑼ ࿑䋭㪈㩷 䊔䉪䊃䊦䊐䊷䊥䉣䉴䊕䉪䊃䊦䈱Ყセ㩷
Ᏹᤨᓸേ䈮ၮ䈨䈒ጤᚻ⋵䊶㔑⍹⋆䈱⋚᭴ㅧផቯ
㪈㪌㩷
䊦ᝄ 䈲㔡 Ḯ ㄭ ற 䉋䉍ᄢ 䈐䈭୯ 䈫䈭䈦䈩䈇䉎䇯ᰴ 䈮䇮㔑 ⍹ ⋆
ౝ䈱 Shizukuishi(JMA)䈪᷹ⷰ䈘䉏䈢⸥㍳䉕ᢙ୯Ⓧಽ䈜 䉎䈖䈫䈮䉋䉍ᓧ䉌䉏䈢ㅦᐲᚑಽ䈱᳓ᐔ㕙ౝ䈱䉥䊷䊎䉾䊃䉕࿑䋭 㪉䈮␜䈜䇯䈖䉏䉋䉍䇮㔡ᵄ㆐ᓟ䈱10⑽(࿑ਛ⎕✢)એ㒠䈱 㔡േᣇะ䈲᧲ᣇะ䈮ථ䈜䉎ะ(࿑ਛᵄ✢)䈏䉄䉌䉏 䉎䇯䈠䈱 Shizukuishi(JMA)䈮䈍䈔䉎ૐ ᵄᢙᏪၞ 䈱 㔡
േ․ᕈ䉕ᛠី䈜䉎䈢䉄䇮EW ᚑಽ䈮㑐䈜䉎㕖ቯᏱ䉴䊕䉪䊃䊦 䉕࿑䋭㪊䈮␜䈜䇯䈖䉏䉋䉍䇮㔡ᵄ䈱㆐䉋䉍10⑽ㄝએ㒠䇮
ᦼ1⑽એ䈱ᚑಽ䈮䈲ಽᢔᕈᵄേ䇮䈜䈭䉒䈤㕙ᵄᚑಽ 䈱․ᕈ䈏㗼⪺䈮䉏䈩䈇䉎䇯䈠䈱․ᕈ䈲ᦼ1.1-1.2⑽ㄝ 䈮䈩ᦨ䉅㗼⪺䈪䈅䉎䈏䇮ᦼ 3⑽ㄭற䈮䉅䈠䈱ᓇ㗀䈏䉄䉌 䉏䉎䇯࿑ 䋭㪈 䈮␜ 䈚䈢䊐䊷䊥䉣䉴䊕䉪䊃䊦䉋䉍䇮㔡 Ḯ ㄭ ற 䈮䉅 0.5HZ䈮Ყセ⊛ఝ䈭ᚑಽ䈏䉌䉏䉎䈖䈫䈎䉌䇮ᦼ 3⑽ㄭ ற䈱ᚑಽ䈲㔡 Ḯ䈱ᓇ㗀䉕ฃ 䈔䈩䈇䉎䉅䈱䈫ផቯ䈘䉏䉎䇯䈇䈝 䉏䈮䈚䈩䉅䇮Sizikuishi(JMA)䈪᷹ⷰ䈘䉏䈢㔡േ䈱㐳ᦼ ᚑಽ䈲㕙ᵄᚑಽ䈪䈅䉐䈉䈫ផቯ䈘䉏䉎䇯
㪊㪅㩷㩷ᓸേ᷹ⷰ䈱ⷐ㩷
ᷓㇱਅ᭴ㅧ䉕ᛠី䈜䉎䈢䉄䈱䉝䊧䊷᷹ⷰ䈫㔑⍹⋆䈱 䈾䈿ਛᄩ䈮䈍䈔䉎᧲ᣇะ䈱ጀ᭴ㅧ䉕ᛠី䈜䉎䈢䉄䈱න ὐ᷹ⷰ䉕1999ᐕ 115ᣣ䈎䉌6ᣣ䈮䈎䈔䈩ታᣉ䈚䈢䇯ฦ
᷹ⷰ䈱᷹ቯ⟎䈲࿑㧙䈮␜䈚䈢䈫䈍䉍䈪䈅䉎䇯
䉝䊧䊷᷹ⷰ 䈲⋆ౝ 䈱ᒝ 㔡᷹ⷰὐㄭற 䈱ᷓㇱਅ ᭴ ㅧ 䉕ផ ቯ 䈜䉎䈢䉄䇮㔑 ⍹ ✚ ว ㆇ േ ႐ 䈪ታ ᣉ 䈚䈢䇯ᷓ ㇱ ⋚ ᭴ ㅧ䈱ផቯ䈲䇮Aki3)䈮䉋䉍ឭ᩺䈘䉏䈩ᦨㄭ䉋䈒↪䈇䉌䉏䉎䉋䈉䈮 䈭䈦䈩䈇䉎ห৻䈱2ὐ䈪䈱ਅേᚑಽ䈱หᤨ᷹ⷰ⸥
㍳䈮ၮ䈨䈒ⓨ㑆⥄Ꮖ⋧㑐㑐ᢙᴺ(SPAC ᴺ)4,5)䈮䉋䈦䈩㕙 ᵄ䈱⋧ㅦᐲ䉕▚䈚䇮᷹ⷰ䊶ℂ⺰⋧ㅦᐲ․ᕈ䈏ᢛว䈜 䉎䉋䈉䈮䇮⋚᭴ㅧ䉕⹜ⴕ㍲⺋⊛䈮᳞䉄䉎䈫䈇䈉ᵹ䉏6)䈪ታᣉ 䈚䈢䇯᷹ቯ䈮㓙䈚䈩䇮䉝䊧䊷ඨᓘ 150䌭䈫䈚䇮䈱5ὐ䉕
⒖േ䈘䈞䈩᷹ቯ䈚䈢䇯
නὐ᷹ⷰ䈲࿑㧙 䈮␜䈜㔑⍹⋆䈱䈾䈿ਛᄩ䈱᧲᷹
✢䈮ᴪ䈦䈢 12 ὐ䈪ታᣉ䈚䈢䇯㩷 ᷹ቯ䈲䉰䊷䊗ဳ䈱ㅦᐲ⸘
(᧲੩᷹ᝄ䋺VSE-15D)䉕↪䈇䇮䉰䊮䊒䊥䊮䉫ᵄᢙ 100Hz 䈮䈩ADᄌ឵䈘䉏䈢䊂䉳䉺䊦䊂䊷䉺䉕⋥ធPC䈪⸥㍳䈜䉎ⵝ
⟎(SPC-35N)䉕↪䈇䈩ታᣉ䈚䈢䇯䉁䈢䇮䈇䈝䉏䈱ὐ䈪䉅ㅦ
ᐲᚑಽ䉕ኻ⽎䈫䈚䇮3 ಽ㑆䈱᷹ቯ䉕ታᣉ䈚䈢䇯ฦ᷹ⷰὐ䈪䈲
᳓ᐔ2ᚑಽ (NS䇮EW)䈍䉋䈶ਅേᚑಽ䈱3ᚑಽ䉕ኻ⽎䈫 䈚䈢䇯ฦὐ䈪ᓧ䉌䉏䈢᳓ᐔ2ᚑಽ䉋䉍▚䈚䈢䊔䉪䊃䊦䉴䊕䉪䊃 䊦䈫ਅേᚑಽ䈱䉴䊕䉪䊃䊦Ყ(H/V䉴䊕䉪䊃䊦)䈱ථᦼ䈮 ၮ䈨䈐䇮᧲ᣇะ䈱ጀ᭴ㅧ䈮䈧䈇䈩ᬌ⸛䉕ⴕ䈦䈢䇯
㪋㪅㩷㩷ⓨ㑆⥄Ꮖ⋧㑐㑐ᢙᴺ㩿㪪㪧㪘㪚 ᴺ㪀䈮䉋䉎⋚᭴ㅧ䈱ផ ቯ㩷
䋨㪈䋩㩷 ⋧ㅦᐲ䈱ផቯ
ᒻ䉝䊧䊷䈍䉋䈶ਛᔃὐ䈱2ὐX䇮Y᷹ⷰ䈘䉏䈢⸥㍳䈮 䉅䈫䈨䈐ᝄേᢙ㱥 䈗䈫䈮ⓨ㑆⥄Ꮖ⋧㑐㑐ᢙ㱝(㱥) 䉕ᰴᑼ 䈮䉋䉍▚䈜䉎䇯ⓨ㑆⥄Ꮖ⋧㑐㑐ᢙ㱝(㱥) 䈲䇮ᒻ䉝䊧䊷
䈱iὐ䈫ਛᔃὐ㑆䈱ⓨ㑆⥄Ꮖ⋧㑐㑐ᢙ䈲2ὐ䈪᷹ቯ䈘䉏䈢
⸥㍳䈱䍘䍩䍎䍸䍻䍛䈱ታᢙㇱ䈫䈚䈩ᓧ䉌䉏䉎ⓨ㑆⥄Ꮖ⋧㑐㑐ᢙ䉕 ਛᔃὐ䈎䉌ᒻ䉝䊧䊷䈱ฦ᷹ὐ䈮ኻ䈜䉎ᣇᐔဋ䈜䉎䈖䈫 䈪▚䈚䈢䇯䈖䈖䈪䇮SXY,i(㱥,㱔) 䈲䈱᷹ὐi䈫ਛᔃὐ 㑆䈱䉪䊨䉴䉴䊕䉪䊃䊦䇮SX,i(㱥,㱔)䋬SY,i(㱥) 䈲䈱᷹ὐi 䈫ਛᔃὐ䈮䈍䈔䉎䊌䊪䊷䉴䊕䉪䊃䊦䉕␜䈚䈩䈇䉎䇯
࿑䋭㪋㩷 㔑⍹⋆䈮䈍䈔䉎ᓸേ᷹ⷰὐ䈱㈩⟎
࿑䋭㪉㩷 㔡േ䈱᳓ᐔ㕙ౝ䈱㩷
㩷 㩷 㩷 㩷 㩷 ㅦᐲ䉥䊷䊎䉾䊃㩷 ࿑䋭㪊㩷 㕖ቯᏱ䉴䊕䉪䊃䊦㩿㪜㪮 ᚑಽ㪀
㪈㪍㩷
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(1)
㵘䈖䈱ⓨ㑆⥄Ꮖ⋧㑐㑐ᢙ㱝(㱥) 䈲䇮᷹ቯ⸥㍳䉋䉍䈚䈢
81.92⑽㑆䈮䈧䈇䈩䇮㐿ᆎᤨೞ䉕5⑽䈨䈧䈝䉌䈚䈭䈏
䉌8㑆䈮䈧䈇䈩▚䈚䈢䇯䈠䈱㓙䇮ฦ䉴䊕䉪䊃䊦䈲0.2Hz䈱 䊋䊮䊄䉕䈜䉎Parzen Window䈮䉋䉍ᐔṖൻಣℂ䉕ⴕ䈉䈖 䈫䈮䉋䉍▚䈚䈢䇯䈖䈖䈪ᓧ䉌䉏䈢ᵄᢙ䈫ⓨ㑆⥄Ꮖ⋧㑐㑐ᢙ 䈱㑐ଥ䉕࿑䋭㪌䈮␜䈜䇯
ᑼ(1)䈱ฝㄝ䈮␜䈜2ὐ㑆䈱ⓨ㑆⥄Ꮖ⋧㑐㑐ᢙ䈲䇮2ὐ䈪
᷹ቯ䈘䉏䈢ᓸേ䈮2ὐ㑆䉕વ䈜䉎Rayleighᵄ䈱ၮᧄ䊝䊷 䊄䈏ఝ䈮䉁䉏䈩䈇䉎䈫䈱ቯ䈱ၮ䈪䇮╙ 1⒳ 0ᰴ䈱䊔䉾 䉶䊦㑐ᢙ䈱ቯ⟵䉋䉍ᰴᑼ䈱䉋䈉䈮䈜䈖䈫䈏䈪䈐䉎䇯
(2)
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f c J r rk
J Z
Z
U
0 0䈖䈖䈪䇮r 䈲䉝䊧䊷ඨᓘ䇮c(f)䈲ᵄᢙ f 䈮ኻ䈜䉎⋧ㅦ ᐲ䉕䈜䇯⋧ㅦᐲ䈲䇮࿑䋭㪌 䈮␜䈚䈢ⓨ㑆⥄Ꮖ⋧㑐㑐ᢙ 䈮ኻᔕ䈜䉎╙ 1⒳ 0ᰴ䈱䊔䉾䉶䊦㑐ᢙ䈱䉝䊷䉩䊠䊜䊮䊃(=㱥 r/c(f))䈫⋧ㅦᐲ䈱㑐ଥ䉋䉍▚䈚䈢䇯䈠䈱㓙䇮࿑䋭㪌䉋䉍
ᵄᢙ0.5Hz(2.0sec)䈎䉌⚂2.5Hz(0.4sec)䈱㑆䉕ലᵄᢙ Ꮺ䈫䈚䈢䇯䈖䈖䈪ᓧ䉌䉏䈢⋧ㅦᐲ䈫ᦼ䈱㑐ଥ䉕࿑䋭㪍䈮␜
䈜䇯࿑ਛ䈮䈲䇮8㑆䈮䈧䈇䈩▚䈚䈢ⓨ㑆⥄Ꮖ⋧㑐㑐ᢙ䈮 䉋䉍᳞䉄䈢⋧ㅦᐲ䈱ᐔဋ୯(࿑ਛ䂾ශ)䈫䈠䈱㫧㱟㑆䉅ว 䉒䈞䈩⎕✢䈪␜䈚䈢䇯䉁䈢0.7⑽䈎䉌0.4⑽䉁䈪䈲䈳䉌䈧䈐䈏 ᄢ䈐䈇䈖䈫䈎䉌࿑䈱䉋䈉䈮 0.7 ⑽䉋䉍⍴ᦼ䈲䉦䉾䊃䈚䈢䇯࿑
䈮␜䈜᭽䈮䇮⋧ㅦᐲ䈲⚂1300m/s䈎䉌800m/s䈱㑆䈪ᄌ ൻ䈚䈩䈇䉎䇯
䋨㪉䋩㩷 ⋚᭴ㅧ䈱ផቯ
⋚᭴ㅧ䈲䇮ᓧ䉌䉏䈢⋧ㅦᐲ䈱ಽᢔᦛ✢䈮ၮ䈨䈇䈩ផ ቯ䉕ⴕ䈉䇯䈖䈖䈪䇮㔑⍹⋆䈮䈍䈔䉎᧲ᣇะ䈱⾰᭴ㅧ䈲 䈍䈍䉃䈰࿑䋭㪎8) 䈮␜䈜䈫䈍䉍䈪䈅䉎䇯࿑ਛ䈮␜䈜䉋䈉䈮ጀ 䈮䈲╙ 4♿䈱ၸⓍጀ䈏ሽ䈚䇮䈠䉏એᷓ䈮䈲㞲ᣂએ೨䈱 Ყセ⊛ၷ䈇ጤ⾰ጀ䈱䈉䈤㞲ᣂጀ䈏䈎䉌᧲䈮ะ䈎䈦
䈩⭯䈒䈭䉎ะ䈮䈅䉎䈖䈫䈏ಽ䈎䉎䇯
࿑䋭㪍䈮␜䈚䈢⋧ㅦᐲ䈱ᐔဋಽᢔᦛ✢䈮⌕⋡䈜䉏䈳
ᦼ 1.5⑽䉋䉍 1.2⑽䈮䈎䈔䈩⋧ㅦᐲ䈱ૐਅ䈏ᄢ䈐䈇䈖䈫䈏 ಽ䈎䉎䇯䈖䈱䈖䈫䈎䉌䇮ᦨᷓㇱ䈱ጀ(⧰㋕⾰ጤጀ)䈱 S ᵄ ㅦᐲ䈲䇮࿑䋭㪍䈮䈍䈔䉎ᦼ1.7⑽䈎䉌2.0⑽䉁䈪䈾䈿৻ቯ
ะ 䉕␜ 䈜 ⋧ㅦᐲ 䈱୯䉋䉍ᣧ 䈇ㅦᐲ 䇮2000m/s 䈫 ቯ䈚 䈢䇯䉁䈢䇮࿑䋭㪍 䉋䉍ᦨጀ(㞲ᣂጀ)䈱 Sᵄㅦᐲ䈲⍴ᦼ
䈱⋧ㅦᐲ․ᕈ䈮ၮ䈨䈐 800m/s 䈫ቯ䈚䈢䇯࿑䋭㪎 䉋䉍
ጀ䈫ᦨᷓㇱ䈱ጀ䈫䈱㑆䈮ਛᣂጀ䈫ẋᣂጀ䈱 2 ጀ䈏ሽ
䈚 䈩 䈇 䉎 䈏 䇮 䈖 䈖 䈪 䈲 䇮 ጀ 䈫 ᦨ ᷓ ㇱ 䈱 ጀ 䈱 ᐔ ဋ ⊛ 䈭
1400m/s 䉕ਔጀ䈱 Sᵄㅦᐲ䈫ቯ䈚䈢䇯䈘䉌䈮䇮䈠䉏䈡䉏䈱
ጀ䈱⾰㊂ኒᐲ䈲㪄 㪈䈱᭽䈮ቯ䈚䈢䇯䈠䉏䉌䈱ቯ䈱ၮ䈨 䈇䈩䈪䇮ฦጀ䈱ጀෘ䈘䉕ᄌൻ䈘䈞䈭䈏䉌䇮Rayleigh ᵄ䈱ℂ⺰
⋧ㅦᐲ䉕▚䈚䇮᷹ⷰ䈮䉋䉍ᓧ䉌䉏䈢⋧ㅦᐲ䈱ಽᢔᦛ✢
䈫䈱Ყセ䉕ⴕ䈦䈢䇯䋭㪈 䈮䈲䇮ਔ⠪䈏ᦨ䉅ᢛว䈜䉎㓙䈱ጀ
ෘ䉕␜䈚䇮࿑䋭㪍䈮䈲䈠䈱㓙䈱⋧ㅦᐲ䈍䉋䈶⟲ㅦᐲ䈱ℂ⺰
ಽᢔᦛ✢䉅ว䉒䈞䈩␜䈜䇯࿑䋭㪍䈮␜䈜᭽䈮ᦼ1.5⑽䈎䉌 0.8 ⑽䈮䈎䈔䈩䇮ਔ⠪䈱⋧ㅦᐲ䈱ಽᢔᦛ✢䈲䉋䈒৻⥌䈚䈩 䈇䉎䈖䈫䈏ಽ䈎䉎䇯
ᓸേ䈱䉝䊧䊷᷹ⷰ䈪䈲䇮䉝䊧䊷ඨᓘ䈫䈚䈩150m䈱1⒳㘃 䈱᷹ቯ䈪䈅䈦䈢䈢䉄䇮䋭㪈 䈮␜䈜⋚᭴ㅧ䊝䊂䊦䈱䈉䈤ㅦ ᐲ᭴ㅧ䈮䈧䈇䈩䈲ቯ䈱ᬌ⸽䉕ⴕ䈦䈩䈇䈭䈇䇯
࿑䋭㪍㩷 ᷹ⷰ䊶ℂ⺰⋧ㅦᐲ․ᕈ㩷
࿑䋭㪌㩷 ⓨ㑆⥄Ꮖ⋧㑐㑐ᢙ㩷
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㪈㪎㩷
䋭㪈㩷 ផቯ䈚䈢⋚᭴ㅧ䊝䊂䊦
࿑䋭㪎㩷 㔑⍹⋆䈱⾰᭴ㅧ䊝䊂䊦㩷
㪌㪅㩷㩷㪟㪆㪭 䉴䊕䉪䊃䊦Ყ䈱․ᕈ㩷
㩷 䈖䈖䈪䈲䇮࿑䋭㪋 ਛ䈱㔑⍹⋆䈱ਛᄩㇱ䈮䈍䈔䉎᧲᷹✢
䈮ᴪ䈦䈢 12 ὐ䈱ᓸേ᷹ⷰ⸥㍳䉕↪䈇䈩▚䈚䈢᳓ᐔᚑ ಽ䈫㋦⋥ᚑಽ䈱䊐䊷䊥䉣䉴䊕䉪䊃䊦Ყ(H/V 䉴䊕䉪䊃䊦)䉋䉍ᓧ䉌 䉏䉎ථᦼ 䈮ၮ䈨䈐䇮ฦ ὐ䈮䈍䈔䉎⋚䈱࿕ ᦼ䈱 ផቯ䉕ታᣉ䈚䈢䇯䈖䈖䈪䇮᳓ᐔᚑಽ䈲᳓ᐔ 2 ᚑಽ(NS䇮EW) 䈱䊔䉪䊃䊦䉴䊕䉪䊃䊦 2)䈫䈚䈩▚䈚䈢䇯䉁䈢䇮H/V 䉴䊕䉪䊃䊦 䈲䇮᷹ቯ⸥㍳䉋䉍䈚䈢81.92⑽㑆䈮䈧䈇䈩䇮㐿ᆎ
ᤨೞ䉕5⑽䈨䈧䈝䉌䈚䈭䈏䉌8㑆䈮䈧䈇䈩䇮0.2Hz䈱䊋䊮 䊄䉕䈜䉎Parzen Window䈮䉋䉍ᐔṖൻಣℂ䉕ⴕ䈉䈖䈫䈮 䉋䉍▚䈚䈢䇯㩷 ฦὐ䈮䈍䈔䉎8㑆䈱H/V䉴䊕䉪䊃䊦䉕࿑
䋭㪏䈮ᵄ✢䈪␜䈜䇯࿑䈮䈲䇮䈠䉏䉌䈱ᐔဋH/V䉴䊕䉪䊃䊦(ታ
✢)䉅ว䉒䈞䈩␜䈜䇯䈘䉌䈮䇮䈠䈱ᐔဋH/V䉴䊕䉪䊃䊦䉋䉍⺒䉂
ข 䈦䈢㐳 ᦼ(࿑ਛ 䃂)䈫⍴ ᦼ(࿑ਛ 䂾)䈱ථ ᦼ 䈫
᷹ὐ1䉋䉍䈱᳓ᐔ〒㔌䈫䈱㑐ଥ䉕࿑䋭㪐䈮␜䈜䇯࿑䋭㪐䉋䉍䇮 㐳ᦼ䈱ථ䈜䉎ᦼ䈲㔑⍹⋆䈱䈎䉌᧲䈮ะ䈎 䈦䈩ૐਅ䈜䉎ะ䈏䉄䉌䉏䇮䈍䈍䉃䈰࿑䋭㪎䈱⾰❑ᢿ᭴
ㅧ䈎䉌ផ᷹䈜䉎S⎕ㅦᐲ᭴ㅧ䈫⺞䈚䈩䈇䉎䇯䉁䈢䇮䉝䊧䊷ⷰ
᷹ὐ䈮ㄭ䈇᷹ὐ5䇮6䈪䈲䇮ਇቯ䈪䈲䈅䉎䈏ᦼ3.0⑽ઃ
ㄭ䈮䉅ථᦼ䈏䉄䉌䉏䉎䇯䈠䈱ᓸേ䈱ථᦼ䈲䇮䋭 㪈䈮␜䈚䈢⋚᭴ㅧ䊝䊂䊦䈮ၮ䈨䈒Sᵄ䈱㋦⋥䈮ኻ䈜䉎 1ᰴ࿕ᦼ⚂3.0⑽䈫䈍䈍䉃䈰ኻᔕ䈚䈩䈇䉎䇯䈘䉌䈮䇮᷹ὐ 1䈎䉌᷹ὐ9䈮䈍䈔䉎H/V䉴䊕䉪䊃䊦䈮䈲1.2⑽ㄭற䈮䉅䉒 䈝䈎䈮ථ䈏䉄䉌䉏䉎䇯䈖䉏䉌䈱․ᕈ䈱ᗧᕈ䈍䉋䈶ᵄേ
વ ․ ᕈ 䈫䈱㑐 ଥ 䉕 䉌䈎䈮䈜䉎䈢䉄䇮 ᓟ 㔡 ᵄ 䈱વ
⸃ᨆ䈭䈬䉕ⴕ䈉ᔅⷐ䈏䈅䉎䇯
࿑䋭㪐㩷 㩷 ථᦼ䈫᷹ⷰὐ䈱㑐ଥ㩷
㪍㪅㩷㩷䈅䈫䈏䈐㩷
ጤ ᚻ ⋵ ർㇱ 㔡 䈮䉋䉎㔑⍹ ⋆ 䈪ⷰ ᷹䈘䉏䈢 㔡േ䈱․
ᕈ 䉕 䉌䈎䈮䈜䉎䈢䉄䈮ᔅ ⷐ 䈭 ⋚ ᭴ ㅧ 䉕䇮Ᏹ ᤨ ᓸ േ 䈱․
ᕈ䈮ၮ䈨䈐ផቯ䈚䈢䇯䈚䈎䈚䇮䉝䊧䊷᷹ⷰ䈮䈩䉝䊧䊷䉰䉟䉵䈱
⇣䈭䉎᷹ቯ䉕ታᣉ䈚䈩䈇䈭䈇䈢䉄䇮ᷓጀ䊶ᵻጀ⋚᭴ㅧ䈮䈧 䈇䈩䈲䇮ᓟㆡಾ䈭䉝䊧䊷䉰䉟䉵䈮䉋䉎᷹ቯ䉕ታᣉ䈚䇮ᬌ⸽䈫
⹏ଔ䉕ⴕ䈉੍ቯ䈪䈅䉎䇯 ጀᢙ ጀෘ(m) Sᵄㅦᐲ(m/s) ⾰㊂ኒᐲ(t/m3)
1 400 800 2.0 2 400 1400 2.3 3 㩷 2000 2.5
㪈㪏㩷
࿑䋭㪏㪸㩷 㩷 ฦὐ䈮䈍䈔䉎㪟㪆㪭䉴䊕䉪䊃䊦㩷
࿑䋭㪏㪹㩷 㩷 ฦὐ䈮䈍䈔䉎 㪟㪆㪭 䉴䊕䉪䊃䊦㩷
㪈㪐㩷
ෳ⠨ᢥ₂
1) ਛ 䇮㘑㑆ၮ᮸䇮ዊᨋᤩ䇮ᄢⷺᕡ㓶(1999)䇮:ጤᚻ⋵ർㇱ㔡 (1998.9.3)䈮䉋䉎ⵍኂ䈫㔡േ․ᕈ䇮No.35䇮᧲ർၞἴኂ⑼ቇ⎇
ⓥ䇮pp.87-92
2) ᧁ ቇ ળ ✬(1999)䇮THE 1999 JI-JI EARTHQUAKE, TAIWAN -Investigation into Damage to Civil Engineering Structures-.
3) ਛ :䊔䉪䊃䊦䉴䊕䉪䊃䊦䈮䉋䉎㔡േ䈱Ⴧ․ᕈ⹏ଔ䇮ᧁቇ ળ⺰ᢥ㓸䇮No.519䇮pp161-173䇮1995.3
4) Aki,K,S(1957),Space and Time Spectra of Stationary Stochastic Waves, with Specific Reference to Microtremors, Bull. Earth. Res. Inst.,35,415-456.
5) ᧻ጟ ㆐㇢䇮᪢ᴛ ᄐ⟤䇮Ꮞፉ ⑲ᄦ䇮ਅ᭴ㅧផቯ䈱䈢䉄䈱ⓨ㑆
⥄Ꮖ⋧㑐ᴺ䈱ㆡ↪ᕈ䈮㑐䈜䉎ᬌ⸛䇮‛ℂតᩏ䇮╙ 49 Ꮞ䇮╙䋱ภ pp26-41䇮1996
6) Morikawa,H, S.Sawada,K., Toki,J., Akamatsu,D., Nakajima,J., Ejiri and K., Miyakoshi(1999), Estimation of Phase velocities from Microtremors observed at two sites, Proc. 2nd Int. Conf. Earthquake Geotechnical Enginering, 119-124.
7) ᚭㅺੱ䇮ችဈ⧷ᔒ䇮Ḯᩕᱜੱ䇮ᩊ↰ᓼ(1999)䇮䉝䊧䊷ᓸേⷰ
᷹䈮ၮ䈨䈒บၞ䈱ᷓㇱਅ᭴ㅧ䈱ផቯ-2ὐSPACᴺ䈮ၮ䈨 䈒㐳↸䈱᭴ㅧ-䇮᧲ർၞἴኂ⑼ቇ⎇ⓥ䇮35䇮39-42
8) Ꮏᬺᛛⴚ㒮⾰⺞ᩏᚲ⋙ୃ(1996)䇮ℂ⑼ᐕ⺒ᧄ䇮䉮䊮䊏䊠䊷䉺 䊷䉫䊤䊐䉞䉾䉪ᣣᧄፉ䈱⾰䇮ਣༀ(ᩣ)
20
