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Masayuki TAKEMURA, Kenji TORAYA
2015 Volume 15 Issue 7 Pages
7_2-7_21
Published: 2015
Released on J-STAGE: December 25, 2015
JOURNAL
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Damage statistics for the 1944 Tonankai earthquake (M
J=7.9) have been re-evaluated, and seismic intensity distribution in JMA scale (I) is estimated from the collapse rate of wooden houses from the new developed dataset. This covers almost the entire region of the affected area. The areas with I=7 was limited to a part of the Kikukawa city and a part of Fukuroi city in the Sizuoka prefecture, and a part of Nishio city in the Aichi prefecture. The dataset also detects the severe damage region by tsunami in the Mie prefecture. Death claimed a toll of 1183 totally from this event. Many victims originated in these areas, but more than 250 victims originated in the other regions, which are the Handa and the Nagoya cities in the Aichi prefecture, where many munition plants were located. The collapsed buildings in these plants were artificially paid no heed to earthquake disaster due to Second World War. A lesson learned is that not only the strong shaking and the tsunami due to the earthquake, but also the artificiality with a lack of policy killed many people in earthquake.
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Kimitoshi SAKAI, Jun IZAWA, Yoshitaka MURONO, Atsushi HINO
2015 Volume 15 Issue 7 Pages
7_22-7_33
Published: 2015
Released on J-STAGE: December 25, 2015
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In this research, we propose the classification method of the soil condition to determine the design earthquake using the shear strength index of the whole ground as an index for classification. The method makes it possible to select the appropriate soil condition considering the upper limit of the ground response for a large-scale earthquake. We verified that more precise ground motion could be evaluated by the proposed method rather than by the ordinary method with only a natural period. Finally, we proposed the simple method for estimating the shear strength index of the whole ground, and confirmed its efficiency. By using this method, the accuracy of the ground classification for a large-scale earthquake is improved by only ordinary the usual ground survey and a simple calculation method.
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Toshimi SATOH
2015 Volume 15 Issue 7 Pages
7_34-7_48
Published: 2015
Released on J-STAGE: December 25, 2015
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Strong ground motions of the 1987 Chiba-ken-toho-oki earthquake (
MJ6.7) are simulated using our revised stochastic Green's function generation method in which surface waves and scattering waves are empirically considered. The source parameters of the asperity model estimated to fit observed and simulated seismic intensity map in the Kanto basin and strong motions of near-by station-pairs have the average feature of previous intraslab earthquakes. The good agreement of simulated strong motions with observed shows the validity of our revised stochastic Green's function generation method.
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Motoki KAZAMA, Tadashi KAWAI, Tomohiro MORI, Jong kwan KIM, Tomoya YAM ...
2015 Volume 15 Issue 7 Pages
7_49-7_59
Published: 2015
Released on J-STAGE: December 25, 2015
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This paper discuss the new subjects of the liquefaction research seen to liquefaction damage of the Great East Japan Disaster. Specifically, the subject about the liquefaction potential assessment, the subject about the evaluation of ground subsidence caused by liquefaction and the subject seen to the liquefaction damage of a river levee, etc. are discussed based on the damage observed or the experimental result. It was shown that understanding present damage on the extension of the present technology has a limit, and that the prediction and countermeasure technology of the liquefaction damage based on a new concept is necessary.
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Hiroto NAKAGAWA, Takumi HAYASHIDA, Toshiaki YOKOI, Toshihide KASHIMA, ...
2015 Volume 15 Issue 7 Pages
7_60-7_71
Published: 2015
Released on J-STAGE: December 25, 2015
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In this paper, we conducted microtremor exploration in Iwaki city hall in order to investigate the effect of inclined bedrock on microtremor H/V spectrum and obtained phase velocity. For the sake of comparison between observed and theoretical values, velocity structure model was constructed by taking into account both down-hole S-wave logging data and N-value distributions from standard penetration tests. From this study, the following conclusions are made: 1) It was found from the result that the H/V spectra from observation data are in good agreement with those calculated from the obtained 1-D structure models. 2) It has also revealed that observed phase velocities by applying CCA method show a tendency of accuracy degradation in the vicinity of peak frequencies of H/V spectra. On the other hand, the phase velocities are consistent with theoretical ones in the vicinity of frequencies of H/V spectral troughs and in higher frequencies than those. 3) It is also confirmed that the estimated bedrock depth by joint inversion analysis of H/V spectrum and phase velocity is deeper than that determined from geotechnical data, due to the accuracy degradation of phase velocity.
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Kentaro MOTOKI, Kenichi KATO, Atsushi OKAZAKI
2015 Volume 15 Issue 7 Pages
7_72-7_89
Published: 2015
Released on J-STAGE: December 25, 2015
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Strong ground motions higher than 1G were recorded at HKD020 located near the source region of the 2004 Rumoi earthquake. We checked a difference of the peak periods of horizontal to vertical spectral ratio of S-waves among the main shock and the aftershocks in order to confirm frequency range affected by non-linearity of soil behavior. We compared shapes of particle motions of the accelerograms and showed good agreements between synthetic and observed particle motions at HKD020. But synthetic waveforms at the other stations were underestimated for the observed motions for the components of which amplitude are low. We conducted the parametric study for the source model and a simulation with heterogeneous propagation media to interpret a cause of the discrepancy. As a result, earthquake motions relatively far from the source region were affected by scattering of seismic wave but those near the source region can be mostly reproduced with homogeneous media.
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Takao KAGAWA
2015 Volume 15 Issue 7 Pages
7_90-7_99
Published: 2015
Released on J-STAGE: December 25, 2015
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This paper presents spatial variability of periodic characteristics in strong ground motion distributions from both strike slip and reverse faults. Three hundreds fault rupture scenarios are assumed for each fault type. Strong ground motions are simulated by stochastic Green's function method at 10,201 points around the fault, 200 km x 200 km, 2 km mesh. The simulated distributions in each period range suggest that the value of variation coefficient depends on positional relationship between the target fault and site. The results can be used for preliminary assessment of ground motion variation in target period range, and also focusing point of active fault investigation.
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Toru SEKIGUCHI, Shoichi NAKAI
2015 Volume 15 Issue 7 Pages
7_100-7_113
Published: 2015
Released on J-STAGE: December 25, 2015
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In recent earthquakes, a large number of houses on a filled valley ground were collapsed due to earthquakes vibration and landslides. In this study, ground motion characteristics of a filled valley were estimated by microtremor measurements and earthquake observations, at Oyumino in Chiba-city and Tama-Newtown in Hachioji-city. In these places, residential areas were developed on a large scale. The shear-wave velocity structure of the surface layers is modeled based on a large number of borehole logs in Oyumino. This model represents well the structure of the surface soil in Oyumino, and reproduces a suitable soil dynamics behavior, when compared to H/V ratios of microtremor. Based on the constructed soil model, vibration characteristics such as maximum amplification factors have been computed from the multiple reflection theory. In addition, we have evaluated peak ground acceleration (PGA) and peak ground velocity (PGV) by the equivalent linearizing analysis. By using these data, the ground motion characteristics of a filled valley ground were estimated.
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Hirofumi TOYOTA, Susumu TAKADA, Tadashi HARA, Koichiro TAKEZAWA
2015 Volume 15 Issue 7 Pages
7_114-7_120
Published: 2015
Released on J-STAGE: December 25, 2015
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Large-scale liquefaction of reclaimed ground occurred in Urayasu city, Chiba prefecture during the 2011 off the Pacific coast of Tohoku Earthquake, causing severe damage to infrastructure of many kinds. However, slightly damaged areas were also existed where soil improvement had been performed. Then, the portable cone penetration test and the surface wave method were done at heavily liquefied and non-liquefied areas. However, there was not large difference in results obtained between liquefied and non-liquefied areas. Therefore, it was examined what factors were affected on shear wave velocity and liquefaction strength using triaxial tests. As a result, the stress history didn't affect the shear wave velocity of the specimen in spite of an increase of liquefaction strength. Moreover, re-liquefaction characteristics were also discussed in the paper because of a tendency that liquefaction damage expanded during the aftershock. It has been demonstrated that the increase of liquefaction strength induced by stress history vanished by liquefaction history.
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Ikuo TOWHATA, Yuichi TAGUCHI, Toshihiko HAYASHIDA, Yuki HAMADA, Shogo ...
2015 Volume 15 Issue 7 Pages
7_121-7_130
Published: 2015
Released on J-STAGE: December 25, 2015
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The present study addresses the ageing of liquefaction resistance of sand in which the resistance increases with the age of soil. This topic is getting more important in recent times because the more reasonable assessment of the resistance is required for more reliable hazard mapping. This situation is in contrast with the conventional idea in design codes that allows a conservative assessment of the resistance. To achieve this research aim, liquefaction case histories were collected from Tokyo and Osaka-Kobe areas where subsoils of known age either liquefied or not liquefied. Consequently, the ageing effect is able to be assessed quantitatively and the liquefaction resistance of soils over 400-year age can be increased 40% above the conventional assessment in design codes.
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Jun-ichi TENDO, Masayuki NAGANO, Hirotoshi UEBAYASHI
2015 Volume 15 Issue 7 Pages
7_131-7_140
Published: 2015
Released on J-STAGE: December 25, 2015
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During the 2011 off the Pacific coast of Tohoku Earthquake, long-period ground motions were largely amplified in coastal area of the Osaka Bay, resulting in the large drift at the top of Osaka Prefectural Government Sakishima Building. Amplification characteristics of the long period ground motions are investigated for the 3-D geological model of the Osaka Plain subjected to the horizontally incident SH wave using the 3-D finite difference method. Synthetic waves in the Osaka Plain including the Bay area were in good agreement with the observed ground motions. The ground motions in the Osaka Bay area were amplified mainly by 3-D geological condition as the focusing effect of travelling waves.
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Ken MIYAKOSHI, Kojiro IRIKURA, Katsuhiro KAMAE
2015 Volume 15 Issue 7 Pages
7_141-7_156
Published: 2015
Released on J-STAGE: December 25, 2015
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Using the waveform inversion results of recent eighteen crustal earthquakes (M
w5.4-6.9) in Japan, which happened after the 1995 Hyogo-ken Nanbu earthquake, we extracted the source parameters (entire rupture area (S) and asperity area (Sa)) from the inverted heterogeneous slip distributions following the criterion of Somerville
et al.(1999). We recognized that the scaling relationship of entire rupture area S versus seismic moment M
0 obtained in this study coincides with that of Somerville
et al.(1999) for earthquakes with M
w <6.5 and does with that of Irikura and Miyake (2001) for earthquakes with M
w>6.5, respectively. The combined area of asperities over the entire rupture area (Sa/S) is about 0.16 in average for eighteen earthquakes, which is smaller than previous result (0.22) by Somerville
et al.(1999). We examined the relationship between source fault length L estimated from the waveform inversion results and seismic moment M
0. The scaling relationship of L versus M
0 for earthquakes smaller than M
w6.5 is consistent with that of Takemura (1998), whereas those larger than M
w6.5 is consistent with the scaling relation of HERP (Headquarters for Earthquake Research Promotion). We further re-examined the source fault lengths estimated from the waveform inversion results of damaging earthquakes (M
w>6.5), which happened before the 1995 Hyogo-ken Nanbu earthquake. We find that re-examined relationship between source fault length L and seismic moment M
0 for earthquakes with M
w>6.5 before the 1995 Hyogo-ken Nanbu earthquake also coincide with that of HERP.
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Shunsuke TANIMOTO, Tsuyoshi KAWAGUCHI, Tetsuya SASAKI
2015 Volume 15 Issue 7 Pages
7_157-7_172
Published: 2015
Released on J-STAGE: December 25, 2015
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On The 2011 off the Pacific coast of Tohoku Earthquake, the distribution of liquefaction site and the reclaimed area were almost overlapping, which suggested that liquefaction occurred mainly at reclaimed area in Tokyo Bay area. However, the timing and the depth that liquefaction occurred were not clarified. In this study, strong motion records observed in the reclaimed area of Tokyo Bay coast were analyzed in order to obtain the fundamental data for improving the liquefaction assessment method. The timing and the depth of liquefaction at a certain site were estimated based on the wave analysis of the strong motions. The future subjects of the liquefaction assessment method were also discussed based on the comparison between the analysis results and the assessment result by the conventional assessment method.
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Masajiro IMOTO, Nobuyuki MORIKAWA, Hiroyuki FUJIWARA
2015 Volume 15 Issue 7 Pages
7_173-7_179
Published: 2015
Released on J-STAGE: December 25, 2015
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This paper discusses the uncertainty of the long-term probability of the Kanto M8 earthquake along the Sagami trough, central Japan, which has been reported by Earthquake Research Committee, the Headquarter for Earthquake Research Promotion. First, we propose a new method to use of a historical Kanto earthquake sequence in estimating the probability based on simulated earthquake sequences generated with the Brownian Passage Time distribution to match geological and geographical evidence. Next, we examine earthquake sequences generated with the Poisson distribution. Results suggest that the epistemic uncertainty of the Meio Kanto earthquake leads to an uncertainty of 0.7% to 5.3% for 30 yr probability, where the Poisson distribution becomes more likely than the BPT distribution for the 1495 Meio earthquake being one of Kanto M8 earthquakes.
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Hayato NISHIKAWA, Masakatsu MIYAJIMA
2015 Volume 15 Issue 7 Pages
7_180-7_193
Published: 2015
Released on J-STAGE: December 25, 2015
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We have proposed an evaluation formula of amplification factor for
PGA and
PGV expressed by parameters of source spectra and site amplification spectra. The site amplification spectrum in evaluation is evaluated by synthesizing some functions in this paper. The formula, therefore, becomes applicable to amplification spectra with several peaks. Amplification factors evaluated by using records obtained in earthquakes with 6 to 7 of magnitude are compared with one evaluated by the proposed formula. It is clarified that error for
PGV is smaller than that for
PGA by comparison of error between observed and evaluated amplification factors.
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Kimiyuki ASANO, Tomotaka IWATA, Ken MIYAKOSHI, Michihiro OHORI
2015 Volume 15 Issue 7 Pages
7_194-7_204
Published: 2015
Released on J-STAGE: December 25, 2015
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Microtremor array observations and single-station microtremor observations are conducted in the Kaga plain and the Ochigata plain, Ishikawa prefecture, Japan, to improve the three-dimensional velocity structure model for strong motion prediction in this area. The lateral variation of the peak periods estimated from the H/V spectra and phase velocity estimated from the array observation are discussed in terms of three-dimensional structure of subsurface sediment layers and bedrock depth. The peak period is relatively short around Komatsu city in the southern part of the Kaga plain compared to the northern and central part of the Kaga plain, indicating the change in the bedrock depth or thickness of sediment layers, which is not well considered in the present velocity structure models. In the Ochigata plain, our observations indicate the need for improving the present model to explain that the thickness of sediment layers gradually increases along the observation line from northeast to southwest.
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Susumu YASUDA, Keisuke ISHIKAWA
2015 Volume 15 Issue 7 Pages
7_205-7_219
Published: 2015
Released on J-STAGE: December 25, 2015
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The 2011 Great East Japan Earthquake caused liquefaction in many places in the Kanto and Tohoku regions. In residential areas where liquefaction occurred, the ground in the whole area, including lifelines and roads, must be treated by special measures to prevent re-liquefaction. The Ministry of Land, Infrastructure, Transport and Tourism established a new project “Urban liquefaction countermeasure project” after the earthquake. Among several countermeasures, lowering the ground water table has been selected as the most promising in several cities in Kanto region. Several studies on the effect of the lowering the groundwater table were conducted in this paper. Case histories on previous earthquakes showed the critical water table to cause liquefaction-induced damage to wooden houses is around GL-2m. Similar results were obtained by residual deformation analyses. Then it was concluded that lowering the ground water table at the depth of about GL-3m must be enough to mitigate liquefaction-induced damage to wooden houses
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Haruka NAKAI, Masayuki TAKEMURA
2015 Volume 15 Issue 7 Pages
7_220-7_229
Published: 2015
Released on J-STAGE: December 25, 2015
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The Mikawa earthquake (M=6.8) occurred on January 13
th in 1945. This is about one month after the Tonankai earthquake (M=7.9). This event has a small number of Nk, which was defined as the number of totally collapsed wooden houses / the number of death tool, and it occurred during the Second World War. The data summarized by Iida in 1985 has been used for discussing the damage from the Mikawa earthquake, which was estimated from the maximum value of the damage data summarized for the counties. A part of them dose not have municipal data which cannot be found now. In this study, we re-evaluate the data of municipalities from Security Division of Aichi Prefecture of January 14, 1945 and the others for the estimation of the seismic intensity distribution in JMA scale. As a result, seismic intensities in the Okazaki basin, which is alluvial lowland, are relatively larger than those of the Hazu hill zone, irrespective of the distance from the Fukozu fault, which associated surface fault breaks with the Mikawa earthquake. This shows that the influence of the ground condition is the largest factor for the strength of seismic intensity and earthquake damages. On the other hand, it can also be found that the Nk value is especially small in the municipalities including the trace of the Fukozu fault. The cause of the small Nk value will be necessarily discussed in relation to the characteristics of the strong ground motion close to the earthquake fault.
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Ryoichi NAKAMURA, Tomiichi UETAKE, Kazuhito HIKIMA
2015 Volume 15 Issue 7 Pages
7_230-7_241
Published: 2015
Released on J-STAGE: December 25, 2015
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We have developed a method to simulate strong ground motions by combining the stochastic Green's function (SGF) and 3-D attenuation structure. The calculation procedures of our method are as follows. (1)To give source spectra for sub-fault events. (2)To calculate basement spectra considering 3-D Qs structure. (3)To calculate ground surface spectra by multiplication of the site factors to basement spectra. (4)To make time history of ground motions using ground surface spectra and envelope function (Boore, 1983). (5)To create main shock ground motion by superimposing the ground motions from sub-fault events considering lapse time: fault rupture and travel time. (Irikura, 1986) In this study, we reproduced strong motions of the 2003 Tokachi-Oki earthquake(M8) and the 2011 Off the Pacific Coast of Tohoku, Japan earthquake (M9) by using this method. Target sites to evaluate are ground surfaces of the K-NET and the KiK-net observation stations. The 3-D Qs model and site amplification factors estimated by Nakamura (2009) were used in this study. To show validity of this method, we compared calculation results by using the 3-D Qs model with by a uniform Qs model; Qs=100f
1.0. The response spectra of ground motion calculated from the uniform Qs model are underestimated in the long distance areas, e.g. Kinki and Hokkaido in case of the 2011 earthquake, whereas the response spectra using the 3-D Qs model were well reproduced the observed ones. Seismic wave propagates in deeper part for longer distance travels without attenuating. It is necessary to consider the 3-D Qs structure in evaluating the ground motion distribution in a broad area.
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Yoshikazu SHINGAKI, Tetsushi KURITA, Tadashi ANNAKA, Hiroshi OKADA
2015 Volume 15 Issue 7 Pages
7_242-7_252
Published: 2015
Released on J-STAGE: December 25, 2015
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We studied the spatial distribution of seismic motion characteristics at the engineering base layer of the Kanto Plain in Japan. As the index for seismic motion characteristics, the average ratio of 5% damped acceleration response spectra between the observed values and calculated values by an attenuation relation was used. By comparing the spatial distribution of the average ratios with topographical maps and geological maps, we classified the region into 8 zones. The main special features of the average ratios are as follows; (1) In the coastal lowlands, the ratios are approximately equal to 1. (2) In the loam terraces, the ratios in the short period range are large in Chiba and Ibaraki, while they are small in Tokyo and Saitama. (3) In the Sagami Plain, the ratios become large around a period of 1second by the effect of its basin structure. (4) In the areas, which are not classified into the quaternary geology, the ratios are small in the entire range of period.
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Toichiro WATANABE, Toshiaki SATO, Takenori HIDA, Michio IGUCHI, Yuichi ...
2015 Volume 15 Issue 7 Pages
7_253-7_260
Published: 2015
Released on J-STAGE: December 25, 2015
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In this paper, applicability of the proposed model for multi-story wooden structure was verified through comparisons between results of shaking test using 2-storied wooden structure and results of time history analysis using the proposed model. Because uplift of column base is very small in this shaking table test, the examination analysis model is shear spring model which ignore vertical column behavior. Form comparisons between test and analysis results, the proposed model has higher analysis accuracy than the conventional model, which is bi-linear + slip model. This result shows that the proposal model is able to model adequately 2-storied wooden structure.
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Jun SAITA, Yutaka NAKAMURA, Tsutomu SATO, Mitsuhiro TACHIBANA
2015 Volume 15 Issue 7 Pages
7_261-7_274
Published: 2015
Released on J-STAGE: December 25, 2015
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Great Buddha of Kamakura is the second largest bronze Buddha in Japan built in around 1250AD. Kamakura locates at the high earthquake activity area in Japan. Although Great Buddha of Kamakura has repeatedly been attacked by several disasters as earthquake, rain storm or flood, the statue itself has still remained its original shape without serious damage until today. It is quite important for the Great Buddha of Kamakura to understand the vibration characteristics of the head because it relates to integrity of the connection between the body and the head. As a result of microtremor measurement at some points in the head, the vibration less than 10 Hz predominates at the head. Also it is cleared that the vibration over 20 Hz predominates at the body and the predominant frequency of the vibration related to the connection between the body and the head is lower frequency less than 10 Hz. The weight of the head has been estimated about 20 tons and it is remarkable that the vibration characteristics is significantly affected by change of the load about 155 kg at his jaw with removal of the inner small Buddha and other deposits. It suggests that the welding connection moves with a certain level of degrees of freedom but the head vibrates as a unit. Therefore, it pointed out the necessity to consider carefully the connecting situation at each portion in the head.
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Kazunori WADA, Manabu IKEDA, Masamichi SAITO, Kenji YAMASHITA
2015 Volume 15 Issue 7 Pages
7_275-7_283
Published: 2015
Released on J-STAGE: December 25, 2015
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Most seismic damage of steel railway bridges tends to occur in their bearings, particularly that of skewed bridges. From this fact, it is considered that the acting force to the bearing of the skewed bridge is relatively larger than that of the straight bridge. However, only a few studies focusing on the acting force of the skewed bridge are available. In this paper, static and dynamic analysis of real structures with different structural type, skew angle and span length were conducted in order to clarify the behavior and acting force of bearing. As a result, it was found that the acting force concentrated on the bearing at obtuse corner because of the supplemental acting force caused by the difference of deflection between the two main girders. It was also clarified that the bias of the acting force became larger as the out-of-plane stiffness decreased.
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Teruyuki UESHIMA, Hiroo SHIOJIRI, Kenji KANAZAWA
2015 Volume 15 Issue 7 Pages
7_284-7_294
Published: 2015
Released on J-STAGE: December 25, 2015
JOURNAL
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Structural health monitoring technique was applied to an aged arch dam, where long-term continuous observation of ambient vibration /seismic motion was performed over a span of three and a half years and where predominant frequency variation along time was detected, variation during ambient vibration/seismic motion. As the result, the following important matters were made clear; 1) Structural health of an aged arch dam can be evaluated through the monitoring of the predominant frequency variation which are detected as the result of the long-term continuous observation of ambient vibration/seismic motion and its data analysis. 2) It was shown objectively by the numerical value of the predominant frequency that the structural health of the observed aged arch dam was maintained even after the main shock of 2011 Off the Pacific Coast of Tohoku Earthquake, and also lots of its large-scale aftershocks. 3) It was confirmed that the structural health of the observed arch dam was maintained and also that the seismic load unchanges through the fact that the predominant frequency of the observed arch dam unchanged before and after the large-scale earthquakes, which shows that the seismic back-check on the observed aged arch dam is unnecessary even after suffering from large-scale earthquakes.
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Masataka HOSO, Kahori IIYAMA, Takanori ISHIDA, Kohei FUJITA, Yoshihiro ...
2015 Volume 15 Issue 7 Pages
7_295-7_305
Published: 2015
Released on J-STAGE: December 25, 2015
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Integrated Earthquake Simulator (IES) have been developed to provide reasonable earthquake disaster information that is important to reduce damage from earthquakes. In order to predict earthquake disaster with high reliability, a multiple shear spring (MSS) model was applied to the multi degree of freedom (MDOF) model implemented in IES. MSS model is able to simulate a 2D elasto-plastic behavior of building structures. Further, a new MSS model which can consider the difference of story stiffness in each direction was proposed. This study carried out elasto-plastic response analyses by the conventional MDOF model, MSS model and the new MSS model to evaluate the effect of the MSS models on the maximum story drift angle.
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Nozomu IKAWA, Shinji ITO, Takehiko TANUMA, Kazuhiro WATANABE
2015 Volume 15 Issue 7 Pages
7_306-7_315
Published: 2015
Released on J-STAGE: December 25, 2015
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In Osaka, the 40-story high-rise building with visco-elastic dampers was constructed in 1999. The structural frame of this building consists of steel girders and concrete filled steel tubular columns. Earthquake observation has been performed since the building completion. Many records have been observed. Then we made the earthquake response analysis was made using the three dimension frame model with the visco-elastic dampers which considered temperature and frequency dependency, and good correlations were obtained between the earthquake observation records and the analysis results. The vibration reduction effect of the damper was confirmed by comparing the analysis results of the model with dampers and the model with no damper. By comparing the analysis results of the condition that the temperature is quite different, it was confirmed that the vibration reduction effect of the damper has the difference.
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Shoichiro UCHIYAMA, Hiroshi INOUE, Hiroshi IMAI
2015 Volume 15 Issue 7 Pages
7_316-7_323
Published: 2015
Released on J-STAGE: December 25, 2015
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A full-scale shaking table test of Indonesian masonry houses conducted in NIED on June 5, 2014 was filmed with eight full HD movie cameras. 399 video frames were taken for each camera from the beginning of the shaking to the collapse of the building and processed by a SfM (Structure from Motion) software. The behavior of the model can be observed in chronological order from arbitrary viewpoints. SfM can be a powerful tool to observe the dynamic behavior of the whole surface of a model for shaking table tests.
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Yuichi SHIOHAMA, Hiroaki SAKAMOTO
2015 Volume 15 Issue 7 Pages
7_324-7_334
Published: 2015
Released on J-STAGE: December 25, 2015
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Because of characteristic of material and integral construction pipeline, polyethylene pipeline has a high earthquake-proof performance . This paper describes the characteristics of polyethylene materials and integral construction pipeline made of polyethylene, seismic experiments of polyethylene pipeline, seismic calculation of integral construction pipeline, and the damage survey of a large earthquake in recent years in Japan.
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Naoto TERAMURA, Yuma KAWASAKI, Kazuyuki IZUNO
2015 Volume 15 Issue 7 Pages
7_335-7_342
Published: 2015
Released on J-STAGE: December 25, 2015
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No effective method has been established to evaluate internal damage of laminated rubber bearings because it is covered with rubber. This study proposed new health monitoring technique using acoustic emission (AE) method which is one of the non-destructive tests to evaluate damage in the rubber bearings. Cyclic compression tests were performed to the rubber bearings and five AE sensors were attached on the rubber surface. The results showed that AE activities and AE parameters could evaluate the possibility of existing internal damage. Further, the location of internal damage was estimated using source location analysis, and the accuracy of analysis was verified using the microscope observation of cutting plane of the specimen.
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Minoru YAMAMOTO, Shoichi NAKAI, Toru SEKIGUCHI, Kiyoshi FUKUTAKE, Yoic ...
2015 Volume 15 Issue 7 Pages
7_343-7_353
Published: 2015
Released on J-STAGE: December 25, 2015
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The authors have been exploring the feasibility of a special type of foundation, named insulated pile foundation, which consists of a raft foundation and a set of piles installed in the ground that are not connected to the raft. In this paper, seismic observation of scaled models constructed on an actual ground is described together with its simulation analysis. Scaled models include a spread foundation, a piled foundation and a proposed insulated pile foundation. From this study, it was found that the proposed foundation can reduce the response of the foundation during earthquakes and that it also reduces the stress of piles near the pile head by a great deal.
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- System Development for Evaluation on Municipal Basis -
Hiroki KATO, Nobuoto NOJIMA
2015 Volume 15 Issue 7 Pages
7_354-7_367
Published: 2015
Released on J-STAGE: December 25, 2015
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The two-step assessment model for post-earthquake lifeline serviceability of electric power, water and city gas supply systems has been modified and validated by authors. In this paper, we proposed a simple method for performing nationwide evaluation on municipality basis by applying seismic intensity representative of each municipality. Evaluation on arbitrary administrative division (47 prefectures and/or six regional blocks covering the entire Japan) can be performed by summing up the municipal results. For the convenience of users, we developed an Excel/VBA-based tool for quick assessment based on arbitrary input of seismic intensity information. As a demonstration of the system, the affected population and its decreasing process have been shown for a past earthquake (Niigataken Chuetsu Earthquake, 2004) and a scenario-earthquake (The anticipated Nankai Megathrust Earthquake, basic case). As advanced applications, the required amount of emergency water supply and the number of evacuee are evaluated on the basis of the predicted time history of population without water supply.
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Ryota NAKAZAWA, Fumio YAMAZAKI
2015 Volume 15 Issue 7 Pages
7_368-7_377
Published: 2015
Released on J-STAGE: December 25, 2015
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Damage estimation for scenario earthquakes is extensively carried out by local governments in Japan for emergency response planning. However, local governments usually do not possess detailed grid data of lifeline systems with pipe material, diameter and length's information in the grid cell of GIS. The accuracy of lifeline’s mesh data is considered to be highly related to the accuracy of damage assessment results. Therefore, to improve the accuracy of earthquake damage assessment, a correlation analysis is carried out to estimate the sewer pipeline length within a grid cell of 250 m from the corresponding road network’s GIS data for Urayasu city, Chiba prefecture, Japan. The estimated sewer pipeline lengths were compared with the actual lengths from the GIS network data, and the efficiency of the estimation method from road network data is demonstrated.
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Saaya IWASE, Fumio YAMAZAKI
2015 Volume 15 Issue 7 Pages
7_378-7_389
Published: 2015
Released on J-STAGE: December 25, 2015
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Tokyo Metropolitan Government (TMG) conducts a community-based seismic risk assessment for all the city-blocks of Tokyo Metropolis every five years. The 7th seismic risk assessment survey was carried out for two kinds of risk due to earthquakes: building damage due to strong shaking, and fire outbreak and spread. A bedrock motion with the peak ground velocity 30 cm/s was assumed uniformly for all the study areas and site amplification was considered based on topography and subsurface soil type. Building damage was evaluated using empirical vulnerability functions. In this paper, a statistical analysis was conducted for the result of the building damage assessment by the TMG. In the multiple regression analysis, the number of severely damaged buildings per unit area was considered as the dependent variable and several explanation variables were employed, such as the number of buildings for each structural type and construction period, the soil amplification factor. The regression analysis was conducted for all the 5,133 city-blocks of Tokyo Metropolis and an accurate prediction equation was derived.
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Hiroyuki MIURA, Saburoh MIDORIKAWA, Masashi MATSUOKA
2015 Volume 15 Issue 7 Pages
7_390-7_403
Published: 2015
Released on J-STAGE: December 25, 2015
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The effect of observation direction on building damage detection from high-resolution SAR images is discussed by using two pairs of TerraSAR-X images and building damage data in the area damaged by the 2010 Haiti earthquake in order to improve the detection accuracy. The ascending pair and the descending pair of the images observed before and after the earthquake are analyzed. Linear discrimination analysis is applied to the pairs of the images in order to identify the collapsed buildings. The result shows that the accuracy of the damage detection depends on the relation between the observation direction and the building direction. The analysis based on the two pairs of the images achieves higher accuracy than the analysis based on a pair of the images.
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Soji KATO, Yasuko KUWATA
2015 Volume 15 Issue 7 Pages
7_404-7_415
Published: 2015
Released on J-STAGE: December 25, 2015
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The Pacific coast of the Tohoku earthquake that occurred on March 11, 2011 and its aftershocks caused liquefaction in the large area in the mouth of the Tone river. This study attempts to make clear the spatial relationship between buried-pipeline damage and sand-boiling for the liquefaction-induced damage concentration areas in the Kashima region. After specifying sand-boiling area from the aerial photographs, the database of water and sewer pipelines covered with liquefaction sand-boiling are developed in the Geographical Information System. As the result, the pipeline damage ratio in the sand-boiling area became 10 times as high as that in liquefaction-induced damage concentration area. The water-pipeline damage much occurs as the pipe length in the sand-boiling area increases. The location of pipeline damage moves from the center to boundary of sand-boiling according to the pipe length in the sand-boiling area.
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Yoshihisa MARUYAMA, Shigeru NAGATA, Kazue WAKAMATSU
2015 Volume 15 Issue 7 Pages
7_416-7_427
Published: 2015
Released on J-STAGE: December 25, 2015
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The 2011 off the Pacific coast of Tohoku Earthquake caused severe damage to water distribution pipes in the eastern part of Japan. This study investigates the relationship between the damage ratios of water distribution pipes and the peak ground velocities for all affected areas. According to the results, the empirical fragility functions constructed after the previous earthquakes were applicable to estimate the damage ratios after the 2011 Tohoku Earthquake. To obtain more accurate estimations, the correction coefficients for the effects of liquefaction and developed hill should be properly considered in the future study.
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Makoto KAMIYAMA, Hideo KOIDE, Yasuji SAWADA, Hiroshi AKITA, Noriyuki C ...
2015 Volume 15 Issue 7 Pages
7_428-7_443
Published: 2015
Released on J-STAGE: December 25, 2015
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This paper discusses the displacements and strains of ground caused by the crustal movements due to the 2011 Great East Japan Earthquake and the 2008 Iwate-Miyagi Inland Earthquake to investigate the damage distribution of civil engineering structures. The distributions of the co-seismic strains agree well with the ones of damaged sites of civil engineering systems. It is concluded that co-seismic strains induced by crustal movements can damage civil engineering systems when they exceed some 10
-4.7(0.00002)~10
-4.5(0.00003).
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Aino SAKAMOTO, Takenori HIDA, Yoshiyasu YAMANE, Tatsuo IWAOKA, Masayuk ...
2015 Volume 15 Issue 7 Pages
7_444-7_453
Published: 2015
Released on J-STAGE: December 25, 2015
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The super high-rise buildings suffered indoor damages during the 2011 off the Pacific Coast of Tohoku Earthquake. This paper presented comparison of floor responses and indoor damage level of 2 super high-rise residential buildings based on questionnaire survey for the residents. Furthermore, we estimated the response of the buildings during the main shock, based on the nonlinear response analyses. System identification method was applied to the floor response data in order to investigate the cause of difference of the damages between two buildings. As a result, the following conclusions were reached: 1) The maximum acceleration of RC super-high rise buildings during the 2011 off the pacific coast of Tohoku Earthquake could be estimated based on the questionnaire survey on the action difficulty and overturning ratio of furniture. 2) The response of SRC building was larger than the RC building during the earthquake. This difference was caused by the following factors; a) The relationship between predominant period of the input motion and natural periods of two buildings. b) The equivalent damping factor of the SRC building was smaller than that of the RC building.
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