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The mechanism of degradation due to kitchen drainage of lining material for building pits Part1
Shingo YOSHIDA, Tamotsu HASEGAWA, Hiromu TAKAHASHI
2015 Volume 80 Issue 717 Pages
1621-1628
Published: 2015
Released on J-STAGE: November 30, 2015
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In order to elucidate the mechanism of degradation due to kitchen drainage of epoxy resin used as a lining material for building pits, several investigations and experiments were conducted. The drainage water and the floating substance from the pit of building A and B were sampled and analyzed. Trace amounts of short-chain fatty acids were detected from the drainage water, whereas trace amounts of short-chain fatty acids and large amounts of long-chain fatty acids were detected from the floating substances. Experiments to immerse epoxy resin test pieces in the drainage water, the floating substances, the aqueous solution of short-chain fatty acids, and the large amounts of long-chain fatty acids were carried out. Both test pieces immersed in the floating substances and long-chain fatty acids became expanded by swelling. From the results above, it should be concluded that long-chain fatty acids contained in the floating substances are the factors affecting the degradation of epoxy resin as a lining material in pits.
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Hiroki TAKAHASHI, Takeshi YOKOI, Shigeo KAJIURA, Yutaka YOKOYAMA, Rumi ...
2015 Volume 80 Issue 717 Pages
1629-1636
Published: 2015
Released on J-STAGE: November 30, 2015
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The aim of this study is to investigate the difference between skilled workers and beginners focusing on the applied force and the movement of their arms during simplified plastering with mortar.
The force was recorded by force plate and the arm movement was recorded by myo-electric potential from four shoulder and forearm muscles. Five skilled workers and seven beginners were selected as the subjects. They plastered with 200g weight mortar at a time.
As a result, the force and the myo-electric potential of shoulders by the skilled workers tended to be larger until 1.0s from the rising of the force.
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Kwengjoo KOH, Keiichiro SUITA, Masatoshi INUKAI, Tetsuya SASAKI
2015 Volume 80 Issue 717 Pages
1637-1647
Published: 2015
Released on J-STAGE: November 30, 2015
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This paper presents results of full-scale loading test of the corner part of rocking type precast concrete curtain walls subjested to large story drift over 0.17 rad. From test results, the method to estimate the rotation of panels and the deformation of joints are proposed. The failure of curtain walls occurred at the bearing support of a panel and the collision between panels led the failure of the panel at the corner and some pieces of broken concrete have fallen. The method to predict the collision of panels are also proposed and the validity of the method is verified by test results.
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Yu SUZUKI, Akira MITA
2015 Volume 80 Issue 717 Pages
1649-1656
Published: 2015
Released on J-STAGE: November 30, 2015
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In this paper, we propose a method using adaptive extended Kalman filter (AEKF) to estimate inter-story drift angles of all stories from modal responses of a tall building. Along with the inter-story drift angles, natural frequencies, damping ratios are to be estimated. Feasibility of the proposed method is demonstrated by comparing with the existing method.
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Toshiharu ARAKAWA, Ryuki TANIGUCHI, Naohiro NAKAMURA, Takuya KINOSHITA ...
2015 Volume 80 Issue 717 Pages
1657-1666
Published: 2015
Released on J-STAGE: November 30, 2015
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This study evaluates vibration characteristics for a middle-rise steel building based on earthquake observation data. The object building used for school is 44 m height, and eleven stories. Earthquake observation data are recorded on the floor level of RF, 10F, 8F, 5F and ground surface. Data observed during the 2011 off the Pacific Coast of Tohoku Earthquake and ones observed before and after this earthquake are used. Natural frequencies and damping ratios of 1st, 2nd and 3rd mode are estimated byusing ARX model.This analysis identifies that vibration characteristics depend on time passage or vibration amplitude.
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Shuang XING, Yuji MIYAMOTO
2015 Volume 80 Issue 717 Pages
1667-1676
Published: 2015
Released on J-STAGE: November 30, 2015
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This paper focuses on the influence of frozen soil on seismic response of a building supported by pile foundation. Firstly, the saturated sand soil was frozen artificially, and then shaking table tests were conducted. Secondly, seismic responses of building with a different natural frequency or with a different freezing depth in the saturated soil were investigated respectively, and then, bending moments acting on pile in saturated soil and frozen soil were also analyzed. Furthermore, three dimensional finite element analyses were also conducted to investigate the effects of frozen soil on seismic response of a building supported by pile foundation.
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Inverse formulation of variational principles of mechanics and structural optimization part 1
Kohju IKAGO
2015 Volume 80 Issue 717 Pages
1677-1686
Published: 2015
Released on J-STAGE: November 30, 2015
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The shape, boundary conditions of the loads and displacements, and distributions of mass and stiffness of a continuum are given in classical variational principles, whereas an inverse variational principle deals with a type of problems where boundary shape is unknown. Another type of inverse formulation of variational principle proposed in this paper is applicable to sizing optimization or a stiffness identification problem. This paper discusses an inverse formulation of Rayleigh's principle that is useful to identify unknown stiffness for a given eigenvalue and eigenmode.
An analytical example is employed to illustrate that the inverse minimum principle of potential energy proposed in this paper is useful in identifying discretized stiffness distribution of a shear structure having designated eigenvalue and eigenmode.
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Hiroaki OGINO, Takuzo YAMASHITA, Mika KANEKO, Daigoro ISOBE
2015 Volume 80 Issue 717 Pages
1687-1697
Published: 2015
Released on J-STAGE: November 30, 2015
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In this paper, a finite element code which enables to analyze behaviors of furniture under seismic excitation was developed. An algorithm considering frictional contact based upon the penalty method was implemented and some analyses were performed. The developed code was validated by comparing the results with motion experiments of steel cabinets and medical equipment under seismic excitations. In addition, the motion behaviors of medical equipment with casters were numerically investigated for different numerical conditions such as constraints of casters. From the numerical results, it is confirmed that overturning behaviors of steel cabinets under different seismic excitations are well simulated and that the constraints of casters have a great influence on the motion behaviors of medical equipment.
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Osamu KANEKO, Shiori KAWAMATA, Shoichi NAKAI, Toru SEKIGUCHI, Tomohisa ...
2015 Volume 80 Issue 717 Pages
1699-1706
Published: 2015
Released on J-STAGE: November 30, 2015
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The authors carried out static analyses using a foundation structure model in order to simulate the process leading to distinctive damage of pile foundations during the 2011 off the Pacific coast of Tohoku earthquake. Remarkable points of the proposed method were evaluation of nonlinear load-deformation characteristics of pile element and rotational stiffness at pile head depended on axial force and formulation of nonlinear behaviors of soil spring including group pile effect. Results obtained from the analysis in two stages to the process to failure of piles for each loading direction explain fairly well the actual damage of pile foundations. The proposed method can be considered as a practical seismic design method of foundations for severe earthquakes.
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Yoshihiro KIMURA, Yasunori KISHINO, Shuji TAMURA
2015 Volume 80 Issue 717 Pages
1707-1716
Published: 2015
Released on J-STAGE: November 30, 2015
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The steel piles beneath the building structures may buckle when the soil becomes liquefied during the large earthquake. In our previous papers, the static buckling behavior of the steel pile is clarified, but the shaking tests of the frames with circular tube piles and the soil, has not been performed to clarify the dynamic buckling behavior. In this paper, the centrifuge test which is a kind of the shaking tests, is applied for the dynamic behavior of small scaled models with the similarity rule, and it is shown that the collapse mechanism issued from dynamic flexural buckling for the piles in liquefied soil is described, and the piles' strength with liquefied soil is larger than that without soil because of the subgrade reaction.
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Kazuhiko NARITA, Yuki TERAZAWA, Kou MAEHARA, Yuichi MATSUOKA, Ryota MA ...
2015 Volume 80 Issue 717 Pages
1717-1725
Published: 2015
Released on J-STAGE: November 30, 2015
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A large numbers of steel roof bearings in RC gymnasia are damaged at past earthquakes at the 2011 Tohoku Earthquake, mainly due to the out-of-plane response of cantilevered RC walls supporting the roof frame. In the conventional seismic retrofit method, bearings reinforcement with steel corner plates and replacement of all the roof braces are required, therefore uneconomical. In this paper, a detailed energy-dissipation bearing with friction dampers for steel roof reducing the response of cantilevered RC walls is fabricated and dynamic loading tests are carried out. Using the experimental results, their response reduction effect is confirmed by analytical models.
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Daiki KANEKO, Hiroyuki NOGUCHI
2015 Volume 80 Issue 717 Pages
1727-1733
Published: 2015
Released on J-STAGE: November 30, 2015
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The purpose of this study is to reveal the shear properties and evaluate the damping coefficient of the wooden bearing wall. Since a recent ideaof "seismic performance design method" has come to be required in timber structure. And therefore "time history calculation" and "limit strength calculations" are needed even in timber structure. However, the data of the timber structure to their calculation is insufficient. So by fulfilling the above object, we want to allow those calculations in wooden bearing wall, and hopes to improve the seismic design accuracy of timber structure.
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Yuki SHIRAI, Satoshi YAMADA, Hiroyasu SAKATA, Yuko SHIMADA, Shoichi KI ...
2015 Volume 80 Issue 717 Pages
1735-1744
Published: 2015
Released on J-STAGE: November 30, 2015
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The purpose of this study is to describe the failure behavior, ultimate strength, yield strength of anchorbolts and the surrounding concrete under combined loads and the effect of reinforcement in the concrete. Monotonic loading tests were conducted for both headed and bonded anchor bolts in ordinary concrete. The ultimate strength when the anchor bolt ruptures or the bond fractures under combined loads are in good correlations with the design recommendation. However, the ultimate strengths when concrete cone failure occurs are in poor correlation with the design recommendation. New equations are proposed for evaluating the ultimate strength under combined loads. Stiffness deterioration occurs when the anchor bolts yield. The yield strength under combined loads is in good correlations with the estimates based on a beamon an elasticfoundation theory and the M-N interaction curve.
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Ryota MATSUI, Shunji URUI, Masaki TOKUNO, Toru TAKEUCHI
2015 Volume 80 Issue 717 Pages
1745-1754
Published: 2015
Released on J-STAGE: November 30, 2015
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The 2011 Tohoku Earthquake ruptured several asperities at the same time, which generated a large scale and long period ground motion. Recently the higher level of the earthquake ground motion is considered in structural design, and the nonlinearity characteristics such as large plasticity or fracture of members are inevitable issues in seismic performance evaluation of the steel structures. This paper presents the seismic performance of the braced frames is assessed by the time history response analysis program taking fracture of the end of beams and braces into account. The incremental dynamic analysis (IDA) is hired, in order to grasp the ultimate state under extremely large ground motions. The fragility curve was constituted from the analysis results, which provides the member fracture has definitely effect on the seismic performance of the braced frames.
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Shingo KOMATSU, Takao TAKAMATSU, Hiroyuki TAMAI, Teruaki YAMANISHI
2015 Volume 80 Issue 717 Pages
1755-1762
Published: 2015
Released on J-STAGE: November 30, 2015
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The authors propose an anti-symmetric Z-type NC braced frame as a new structural system for a seismic response reduction mechanism based on elastic energy accumulation capability produced by a wedge device. The previous paper described the seismic response reduction performance of a single-story braced frame due to elastic energy accumulation based on shaking table tests and actual-scale numerical analyses. The purpose of this paper is to expand this system to multi-story braced frames. Shaking table tests on two-story specimens are carried out to clarify basic performance, and numerical analyses are used to verify reappearance. Numerical analyses of actual-scale two-story braced frames are conducted to examine seismic response behavior and response reduction capability of multi-story braced frames.
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Hitoshi KUWAMURA, Tsuyoshi KOYAMA, Hiroki OKUNO, Yoshiharu SATO
2015 Volume 80 Issue 717 Pages
1763-1771
Published: 2015
Released on J-STAGE: November 30, 2015
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A testing method for quantifying inundation resistance of flooded houses is developed and is applied to a housing wall furnished with a window. The testing apparatus is composed of a main frame for fixing the tested wall, a reservoir and piping for supplying the outdoor floodwater, and a collector for gathering the inflow of water. The water depths of outside inundation space and inside collector are continuously measured by level gauges. The inundation flows from outside to inside are through an opening for under-floor ventilation, a joint discontinuity at the bottom of wall, and gaps in and around the sash frame of the window. The dimensions and heights of these floodwater inlets are estimated from the test results by employing Torricelli's theorem. Such information will enable engineers to calculate the rate of indoor inundation, which is substantially important for evacuation of residents and valuables.
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Iathong CHAN, Yuji KOETAKA, Keiichiro SUITA
2015 Volume 80 Issue 717 Pages
1773-1783
Published: 2015
Released on J-STAGE: November 30, 2015
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This paper presents a numerical study on 3D steel moment frames with square tube columns. The major parameters are column overdesign factor, shapes of the frames and input direction of ground motion. From the analysis, it is revealed that the relationships between cumulative plastic deformation of columns and column overdesign factor are not affected by the shapes of frames but influenced by amplitude and input direction of ground motion and width-thickness ratio of columns. The required column overdesign factor to keep the damage of columns below the limit of plastic deformation is proposed under the reliability index of 2.0.
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Hitoshi KUWAMURA, Yoshiharu SATO
2015 Volume 80 Issue 717 Pages
1785-1794
Published: 2015
Released on J-STAGE: November 30, 2015
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Local out-of-plane behaviors of an eccentric connection of non-diaphragm CHS-column to beam were investigated through experimental and numerical tests. Such an eccentricity is often met in the practice that the axes of perimeter beams of a steel structural building are shifted outward from the center of column in order to reduce the gap between beam and external wall. The tests demonstrated that such an eccentricity brings a slightly higher strength and an apparently greater stiffness than those of no eccentricity. This is attributed to the enhancement of the membrane action of the cylindrical body. An idea of combining three models of concentric flanges with actual and virtual widths corresponding to the edges of the eccentric flange was proposed and found to yield a good estimation for stiffness as well as strength of the eccentric connection.
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Hiroyuki NAKAHARA, Kazuhiro UCHIDA, Ryosuke HINEI
2015 Volume 80 Issue 717 Pages
1795-1801
Published: 2015
Released on J-STAGE: November 30, 2015
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A 3D-FEM analysis has been conducted to investigate the shearing behavior of eight circular CFT columns which were tested under cyclic shearing force and already reported. The test results were traced precisely by those of the FEM analysis in any variations of the test parameters which were axial force ratio and diameter to wall-thickness ratio. The shearing strengths calculated by the AIJ Recommendations for CFT, which was established by the superposed strengths of concrete and steel tube, were predicted by the integrated shear stress on the sections by the FEM analysis.
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Seira OWA, Kenichi IKEDA
2015 Volume 80 Issue 717 Pages
1803-1809
Published: 2015
Released on J-STAGE: November 30, 2015
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The experiments of post-installed adhesive anchoring systems of epoxy injection resin type were taken in focusing on bond failure (bond strength) during fire and after fire. The following conclusions were recognized by their experiments.
1. Bond strength decrease in accordance with increase of temperature in post-installed adhesive anchors.
2. Test condition of acting tensile load for specimens after heating up has a bigger influence compare to heating up temperature for specimens after acting tensile load.
3. Remaining bond strength have the same performance of normal temperature in short term up to 250 °C after fire and cooling down to air temperature.
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-Optimization for required fire proofing material volume using genetic algorithm-
Fuminobu OZAKI, Kenzo HAMAGUCHI
2015 Volume 80 Issue 717 Pages
1811-1819
Published: 2015
Released on J-STAGE: November 30, 2015
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In case when fire resistance of a steel frame is verified in seismic regions, it is important to understand effect of seismic design on fire resistant design, to improve both seismic and fire resistant performance. The main purpose of this paper is to clarify relationships between an input amount of fire proofing material and a seismic structural resistant margin, which is given by a quotient of horizontal load-bearing capacity divided by required horizontal load-bearing capacity of the steel frame. To estimate minimum value of the required fire proofing material volume, genetic algorithm (GA) analyses are conducted. From minute investigation of the parametric numerical results, it was clarified that the fire proofing material volume can be reduced in the case of steel frame with the large seismic structural resistant margin, because the redundant seismic frames have the high collapse temperatures and large thermal capacity of the large cross-sectional area members.
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