Pin‐supported walls for enhancing the seismic performance of building structures     

Zhe Qu  Akira Wada  Shojiro Motoyui  Hiroyasu Sakata  Shoichi Kishiki 《地震工程与结构动力学》2012,41(14):2075-2091

An application of a pin‐supported wall‐frame system in retrofitting an eleven‐story steel reinforced concrete frame is introduced. The retrofit aims at enhancing integrity and avoiding weak story failure in an existing moment‐resisting frame. Seismic performance of the building before and after the retrofit is assessed through nonlinear dynamic analysis. The results show that the pin‐supported walls are effective in controlling the deformation pattern of the ductile frame and hence in avoiding weak story failure. With the well‐controlled deformation pattern, carefully arranged energy dissipating devices are able to concentrate energy dissipations so that damage to the rest of the structure can be significantly reduced. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

U–Pb and fission‐track dating of a submarine pyroclastic rock from southwest Japan          下载免费PDF全文

Takashi Ninomiya  Sho Taniguchi  Shoichi Shimoyama  Koichiro Watanabe  Tohru Danhara  Hideki Iwano  Kazuyuki Shiraishi  Chitaro Gouzu 《Island Arc》2017,26(6)

The Okinoshima Formation crops out on Okinoshima Island and comprises a thick sequence (> 200 m) of pyroclastic rocks and alternating beds of sandstone and mudstone. Because Okinoshima Island is located between Honshu and Tsushima Island, the Okinoshima Formation potentially provides an important record of volcanism during the opening of the Japan Sea in northwest Kyushu, as well as a record of the formation of the present Genkai Sea region. In consideration of the lack of previous geochronological work, dating (fission‐track and U–Pb) of igneous zircons extracted from the Okinoshima Formation were undertaken and studied the clay mineral alteration in the pyroclastic material in order to reveal its thermal history. These data are used to constrain the age of the Okinoshima Formation and the present Genkai Sea region. Our results show that no thermal event has reset the fission‐track age after deposition of the pyroclastic rocks, and that the Okinoshima Formation was deposited at 16.2 Ma. The present Genkai Sea region is a deep‐sea basin, and its formation at 16.2 Ma was accompanied by submarine volcanism and rapid subsidence that marked the climactic stage of Japan Sea formation. After 16 Ma, the tectonic setting of the present Genkai Sea region changed from one of extension (related to the formation of the Japan Sea) to one of compression, with uplift occurring under the influence of the clockwise rotation of southwest Japan. Consequently, after 16 Ma the present Genkai Sea region became isolated from the forming processes of the Japan Sea.  相似文献   

Accuracy assessment of QuickBird stereo imagery   总被引：2，自引：0，他引：2  

Mayumi Noguchi  Clive S. Fraser  Takayuki Nakamura  Takahiro  Shimono  Shoichi Oki 《The Photogrammetric Record》2004,19(106):128-137

The Geographical Survey Institute of Japan has recently carried out an evaluation of the metric performance of QuickBird stereo satellite imagery. This paper describes the accuracy assessment of the sensor orientation and geopositioning phases of the study, the aim of which was twofold. First, it was desired to confirm the metric potential of QuickBird imagery for 1:25 000 scale topographic mapping. Second, a determination was to be made of the accuracy attainable from the Basic image product. The techniques of rational functions and affine bundle adjustment were employed, the former with bias compensation. The results obtained both reassert the high precision of the rational functions approach and cast doubt upon the applicability of the 3D affine model for accurate geopositioning from QuickBird imagery.  相似文献   

Simulation analysis of ground liquefaction induced by earthquake     

Tadahiko Shiomi  Shoichi Tsukuni  Munenori Hatanaka  Yoshiyuki Tanaka  Yoshio Suzuki  Tadayoshi Hirose 《Computers and Geotechnics》1987,4(4):221-245

A dynamic effective stress analysis with the finite element method has long been recommended to predict the liquefaction phenomena of sandy soil by authors and Zienkiewicz et al. as well as the similar approaches by the others. Our approach of the analysis is summarized in the first.

Until recently, however, these approaches has not commonly been used as the means of design, although its capability of prediction is appreciated by geotechnicians. This method has been neglected because of the lack of verification studies of soil models of sand and mathematical formulation for boundary problems of liquefaction phenomena. Therefore the verification of the numerical method to evaluate liquefaction potential are urgent requirement of the recent engineering practice. To respond this requirement, extensive numerical studies on the liquefation simulations are performed by DIANA program for shaking table tests which have been conducted by the authors. The test models are soil-structure type models with combination of homogenous ground and partially improved ground by compaction.

The good performance of our approach is proved by the results of numerical simulation showing good agreement with experimental data in terms of response acceleration, excess pore pressure, and deformation profile. It is also demonstrated that the numerical results can provide substantial information to understand the mechanisms of soil ground behavior which is not easily obtained by experiments.

The procedure to identify soil constants for the reflecting surface model is also reported in details.  相似文献   

Japanese Ocean Flux Data Sets with Use of Remote Sensing Observations (J-OFURO)   总被引：1，自引：1，他引：1  

Masahisa Kubota  Naoto Iwasaka  Shoichi Kizu  Masanori Konda  Kunio Kutsuwada 《Journal of Oceanography》2002,58(1):213-225

We have constructed ocean surface data sets using mainly satellite data and called them Japanese Ocean Flux data sets with Use of Remote sensing Observations (J-OFURO). The data sets include shortwave radiation, longwave radiation, latent heat flux, sensible heat flux, and momentum flux etc. This article introduces J-OFURO and compares it with other global flux data sets such as European Centre for Medium Range Weather Forecasting (ECMWF) and National Center for Environmental Prediction (NCEP) reanalysis data and da Silva et al. (1994). The usual ECMWF data are used for comparison of zonal wind. The comparison is carried out for a meridional profile along the dateline for January and July 1993. Although the overall spatial variation is common for all the products, there is a large difference between them in places. J-OFURO shortwave radiation in July shows larger meridional contrast than other data sets. On the other hand, J-OFURO underestimates longwave radiation flux at low- and mid-latitudes in the Southern Hemisphere. J-OFURO latent heat flux in January overestimates at 10°N–20°N and underestimates at 25°N–40°N. Finally, J-OFURO shows a larger oceanic net heat loss at 10°N–20°N and a smaller loss north of 20°N in January. The data of da Silva et al. in July show small net heat loss around 20°S and large gain around 20°N, while the NCEP reanalysis (NRA) data show the opposite. The da Silva et al. zonal wind speed overestimates at low-latitudes in January, while ECMWF wind data seem to underestimate the easterlies. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Probability Distribution of Surface Wave Slope Derived Using Sun Glitter Images from Geostationary Meteorological Satellite and Surface Vector Winds from Scatterometers     

Naoto Ebuchi  Shoichi Kizu 《Journal of Oceanography》2002,58(3):477-486

The probability distribution of the sea surface slope has been estimated using sun glitter images derived from the visible wavelength radiometer on the Geostationary Meteorological Satellite (GMS) and surface vector winds observed by spaceborne scatterometers. The brightness of the visible images is converted to the probability of wave surfaces which reflect the sunlight toward GMS in grids of 0.25° × 0.25° (latitude × longitude). The slope and azimuth angle required for the reflection of the sun's rays toward GMS are calculated for each grid from the geometry of GMS observation and location of the sun. The GMS images are then collocated with surface wind data observed by three scatterometers. Using the collocated data set of about 30 million points obtained in a period of 4 years from 1995 to 1999, the probability distribution function of the surface slope is estimated as a function of wind speed and azimuth angle relative to the wind direction. The results are compared with those of Cox and Munk (1954a). The surface slope estimated by the present method shows a narrower distribution and much less directivity relative to the wind direction than that reported by Cox and Munk. It is expected that their data were obtained under conditions of growing wind waves. In general, wind waves are not always developing, and the slope distribution might differ from the results of Cox and Munk. Most of our data are obtained in the subtropical seas under clear-sky conditions. This difference in the conditions may be the reason for the difference of slope distribution. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Analysis of rainfall characteristics of the Madden–Julian oscillation using TRMM satellite data     

Juntaro Morita  Yukari N. Takayabu  Shoichi Shige  Yasumasa Kodama 《Dynamics of Atmospheres and Oceans》2006,42(1-4):107

Rainfall characteristics of the Madden–Julian oscillation (MJO) are analyzed primarily using tropical rainfall measuring mission (TRMM) precipitation radar (PR), TRMM microwave imager (TMI) and lighting imaging sensor (LIS) data. Latent heating structure is also examined using latent heating data estimated with the spectral latent heating (SLH) algorithm.The zonal structure, time evolution, and characteristic stages of the MJO precipitation system are described. Stratiform rain fraction increases with the cloud activity, and the amplitude of stratiform rain variation associated with the MJO is larger than that of convective rain by a factor of 1.7. Maximum peaks of both convective rain and stratiform rain precede the minimum peak of the outgoing longwave radiation (OLR) anomaly which is often used as a proxy for the MJO convection. Stratiform rain remains longer than convective rain until 4000 km behind the peak of the mature phase. The stratiform rain contribution results in the top-heavy heating profile of the MJO.Associated with the MJO, there are tri-pole convective rain top heights (RTH) at 10–11, 7 and 3 km, corresponding to the dominance of afternoon showers, organized systems, and shallow convections, respectively. The stratiform rain is basically organized with convective rain, having similar but slightly lower RTH and slightly lags the convective rain maximum. It is notable that relatively moderate (7 km) RTH is dominant in the mature phase of the MJO, while very tall rainfall with RTH over 10 km and lightning frequency increase in the suppressed phase. The rain-yield-per flash (RPF) varies about 20–100% of the mean value of 2–10 × 10⁹ kg fl⁻¹ over the tropical warm ocean and that of 2–5 × 10⁹ kg fl⁻¹ over the equatorial Islands, between the convectively suppressed phase and the active phase of MJO, in the manner that RPF is smaller in the suppressed phase and larger in the active phase.  相似文献   

Temperature distribution of the upper surface of the subducted Philippine Sea Plate along the Nankai Trough, southwest Japan, from a three-dimensional subduction model: relation to large interplate and low-frequency earthquakes   总被引：1，自引：0，他引：1  

Shoichi Yoshioka  Koji Murakami 《Geophysical Journal International》2007,171(1):302-315

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Numerical simulations of deformation and dynamics of horizontally lying slabs   总被引：2，自引：0，他引：2  

Shoichi Yoshioka  Hiroyasu Sanshadokoro 《Geophysical Journal International》2002,151(1):69-82

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Geochemical constraints on the depositional environment of the 1.84 Ga Embury Lake Formation,Flin Flon Belt,Canada     

Kento Motomura  Shoichi Kiyokawa  Minoru Ikehara  Kentaro Tanaka  Yuji Sano 《Island Arc》2020,29(1)

The Flin Flon Belt of Canada contains Paleoproterozoic volcanic–sedimentary sequences that are related to the Trans‐Hudson Orogeny. The sequences include island arc volcanic and volcaniclastic rocks (Amisk Group) that are unconformably overlain by subaerial sedimentary rocks (Missi Group), and younger deep facies sediments. In the Flin Flon area, several north–south trending faults divide the sequences into blocks and obscure the depositional environment of the deep facies sediments. Locally, within the Flin Flon area, the Embury Lake Formation is in fault contact with island arc volcanic–sedimentary sequences of the Amisk and Missi Groups. To identify the depositional environment of the Embury Lake Formation, we used lithologic and geochemical approaches. Here, we report carbon isotopic values in organic matter (δ¹³C_org) and sulfur isotopes (δ³⁴S), as well as total organic carbon and total sulfur measurements for the black shale in the formation. Samples were taken from a drill core that contains alternating bands of sandstone and black shale. Pyrite in the black shale is divided into four textural types: euhedral, vein‐type, elliptical, and microcrystalline. Microcrystalline pyrite is typically generated by microbially mediated sulfate reduction. An extremely low S/C ratio (avg. = 0.04) is consistent with lacustrine deposition. The ranges of δ¹³C_org (?36 ‰ to ?27 ‰) and δ³⁴S (+3.0 ‰ to +7.7 ‰) values can be explained by bacterial photosynthesis that involved Calvin cycle and acetyl CoA pathways, and sulfate reduction in a low‐sulfate environment. Considering the depositional age reported in a previous study of < 1.84 Ga, the Embury Lake Formation was likely emplaced in a lacustrine setting during the Trans‐Hudson Orogeny.  相似文献