5 th IASPEI/IAEE International Symposium Effects of Surface Geology on Seismic Motion 2016 August 15-17 Taipei Taiwan Kazuyoshi Kudo, Seiji Tsuno, Tatsuo Kanno, and Hideki Nagumo
Learn a lesson from the past / or Study the history, and obtain the wisdom for tomorrow./
OU OUTL TLINE NE OF OF MY Y TA TALK K TO TODAY Y (1 (1): ): Short His istory y of f Seis ismic ic Ob Observa vatio ions in in t the Unde Un derground d (B (Borehole le), ), Mo Mostly ly i in J Jap apan an Effor orts s of of the Fi First st Stage ge in Japan (1887 1887-1940 1940) Develop opments s of of Bo Borehol ole Seism smom ometer and Obse servation ons s (1950 1950-1970 1970) In Increase se of of Bo Borehol ole Obse servation on Sites s and Seism smic Pros ospecting g (1970 1970-1995) 1995) Non-linear, Q , Test sites: Do not touch today
OU OUTL TLINE NE OF OF MY MY TA TALK K TO TODAY Y (2 (2): ): Some To Topi pics of f Deep B p Borehole le Obs bserva vatio ions, , its H it His istory a and d Recent Issues Deep Bo Bore rehole Ob Observ rvat ation in S Sedime menta tary ry Ba Basins Deep Bore rehole Ob Observ rvat ation at at Sti tiff Soils or r Rock Site tes Contr tributi tion n of th the KiK KiK-net et fro rom D Deep Bore rehole e site tes Recent t Unexpect cted d Gr Ground Moti tion an and D Deep Bore reholes es Ob Observ rvat ations in th the Nuclear ar Power r Sta tati tions in J Jap apan an
Depths(m) of Year Authors Site Name Type of Instruments Instrument Kasumigaseki 1887 Milne Surface & -3m (Tokyo) 1892 Sekiya and Hongo Ewing type horizontal Surface & -5.4m Omori (Tokyo) seismograph Surface, -9.1m & 1934 Saita and Marunouchi Ishimoto type Suzuki (Tokyo) -20.6m (two wells) accelerographs Imamura‘s displacement seismograph, Ishimoto’s Komaba 1934 Inoue Surface & -9m (Tokyo) Accelerographs, Tremor recorder Horizontal displacement Surface, -150m, 1951 Kanai and Hitachi Mine seismograph (To = 1 Tanaka (Ibaraki Pref.) -300m, and 450m sec), Magnification = 150
Sekiya and Omori(1891) Surface: The ripple are very prominent Pit: No ripples Ripple are super imposed on slower undulation of 2 sec. (EW) and 3 sec. (NS)
Observation pits used by Saita and Suzuki (1934) Alluvium Look down the 68f (~21m) pit from the surface Diluvium
Examples of records reproduced from Saita and Suzuki (1934) : Ishimoto’s Accelerographs were used
Quasi Spectral Ratio of Ground Motions between Surface and Underground (-20.6 m) Dominant Period= 0.7, 0.2 sec 10 (Surface/-20.6m) Amplitude Ratio Indication by Ishimoto(1932) 0.1 0.5 1.0 Apparent Period(sec) by Zero-crossing Reproduced from Saita and Suzuki (1934) with additional explanations.
Deep underground observations led to the discovery of existence of the 0 m M 2 waves (Sezawa and Kanai, 1935) 150 m 300 m 450 m Reproduced from Kanai and Tanaka (1951)
Developments of Borehole Seismometers (1960~1970) ＊ Borehole seismometers (electromagnetic) were developed and they contributed to earthquake observation at various places and at some depths in a field of earthquake engineering. ＊ Representatives of borehole seismometers are Kanai and Tanaka (1958) and Shima (1962). But, we had to wait the strong motion borehole sensor until the development of the servo-type accelerometers. ＊ S-wave velocity measurements for quantitative evaluation of the effects of subsoil layers were one of a major topics. The special geophone for velocity logging developed by Kitsunezaki (1967) accelerated the site characterizations studies and measurements.
Comments on Studies after 1970s The works using the strong motion records at downhole sites have been reviewed taking the opportunity of the International Symposium on Effects of Surface Geology and other international symposiums/workshops (e.g., Finn, 1992; Archuleta and Steidl, 1998; Kawase, 2006). We cannot go into detail today, but the borehole measurements have played a significant role to understand the non-linear behavior of soils during destructive earthquakes occurred during 1980s and 1990s, including liquefaction of soils (Wen, et al., 1994; Iai et al., 1995, Kawase et al., 1996; Aguire and Irikura, 1997).
Deep Borehole Observation in Kanto Basin, Japan 1971~, by NIED Reproduced from Suzuki et al.(1981)
Advantages of Deep Borehole(2000~3000m) in Seismology and Earthquake Engineering Original purpose of deep borehole: Increase S/N, and related issues provided by the earthquake prediction research program. Advantages in the field of engineering seismology: Direct un t understa tanding o of am amplificat ation of long period ground moti tion ta taking th the am amplitu tude an and/or s spectr tral al rat atio betw tween surfac ace an and deep g ground. Direct m t meas asurements ts of P- an and S S-wav ave ve velociti ties, Q Q va values (e.g., Oh Ohta ta et al., 1980; Kinoshita, 1986;…….) Gras asp th the i input ( t (up-going) an and r reflecte ted ( (down-goi oing) ) wav aves, Kinoshita ta (1986).
Well-shooting Results at the Iwatsuki Deep Borehole Reproduced from Ohta et al. (1980)
SH-Wave Generator-Gun (Cannon) by Shima and Ohta (1968)
Improvements by New Technology Suspension Method Stacking Source Multi- Receiver Reproduced from Yamamizu(2004)
Example of Recent Geotechnical Data Reproduced from Kobayashi (2012)
Clear separation of up-going and reflected down-going waves; Determination of Q (Kinoshita, 1986) Reproduced f from Kinoshita a (1986)
Deep Borehole Array Observation at Stiff Soils or Rock Sites Iwaki, , Tomioka oka (Fukus ushima ima Pref., ., Japan) ) ： Omote et al., （ 1984 1984 ） Major r targets ts was to understa stand d the bedrock ck motion n (or earthq hqua uake ke source ce nature) e) and amplifi ifica catio ion n /attenu nuatio tion n (Q) in surfac ace layers. rs. Very importa tant t manage geme ments ts were that the observe ved d data have been release sed d on demand nd of users. s. The data contrib ibut uted d to presen ent t the empiric ical al predict ctive ive model l of bedroc ock k motion on, , the evaluat ation on of vertica cal motion on, , and others. s. Those e are especial ially ly request sted ed for assessi ssing ng the ground d motion on for nuclear ar power stations. ons. Results: s: e.g., Takah ahash ashi i et al., 1992; Takemu mura ra, , et al., 1993; Noda et al., 2002, Reproduced from Omote et al. (1984)
Deep borehole array records are significant to confirm the simulation techniques: good example for the records obtained at Tomioka borehole site Reproduced from Iwata et al. (1992)
Lesson from hard rock site - Ikata Nuclear Power Stations- Reproduced from Shikoku Electric Power Co. (2013)
Reproduced from Shikoku Electric Power Co. (2013)
Contribution of deep borehole data at hard rock sites Ikata Nuclear Power Plant, Shikoku Electric Power Co., locates on very hard rock (2.2~3.5 km/s) site except surface; then amplifications of horizontal motions inside rock is very small as theoretically understandable. Sato et al. (2015) obtained Q (as left figure) with less frequency dependency. It is very interesting that Q in the homogenous hard rock site differ frequency dependency from many results of Reproduced from Sato(2015) Q in sedimentary layers.
Contribution from deep borehole sites of the KiK-Net Contr tributi tion n of KiK KiK-net net: Man any, y, W Worl rldwide e Use, , Mostl tly y shal allow site te d dat ata a hav ave been used. Deta tail d discussions ns ar are fo found in Kaw awas ase (2006): ESG2 G2006 6 Deep bore rehole site tes ar are quite te limite ted e except t for K r Kan anto to bas asin. An An E Exam ample of th the Co Contr tributi tion on of th the D Deep bore rehole e site te: OS OSKH002( 2(Ko Konoh nohan ana, a, Os Osak aka) a) . . Evi vidence ： a a high-ri rise building (55F) suffere red non-str truct ctura ral but t considera rable e dam amag age (e (e.g. eleva vato tor, r, door, r, ceiling etc tc.) fro rom th the 2011 Tohoku ear arth thquak ake. The s str trong mo moti tion re record rds were re obta tained in th the high-ri rise building (Building Res. In Inst. t. : : http://smo.kenken.go.jp/smreport/201103111446 ) )
Osaka Prefectural Government Sakishima Office Building Reproduced from Iiba et al. (2012): Building Research Data, No.138, BRI fo~0.15Hz scenery/20110801181 ... ... http://f ://f.ha .hatena.com tena.com/mag magnif ific icentsc
Upper: L Location map of Osaka Bay area showing the Sakishima Offi fice (55F) by red m mark and t the deep b borehole site OSKH02 of the KiK-net by yellow mark. Left: Geotechnical data for OSKH02 provided by N NIED. The s sensors a are installed at the ground s surface and - 2008 m m. Thickness o of sediment is 1600m
KiK-net data OSKH02 and the Interpretations by Kagawa(2013) ⊿ >6 ００ｋ In side of ｍ Osaka basin OSKH02 After NIED Courtesy of Prof. Kagawa
Courtesy of Prof. Kagawa
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