著者

白井 克弘 大町 達夫

出版者

公益社団法人 土木学会

雑誌

構造工学論文集 A (ISSN:1881820X)

巻号頁・発行日

vol.53A, pp.306-312, 2007 (Released:2007-08-01)

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The objective of this paper is how to control waveforms by means of all pass functions. Causal time functions such as earthquake records are factorized into minimum phase shift (MPS) and all pass (AP) functions, which is called factorization. This concept is applied to impulse response of SDOF to investigate effects of AP phases when they are parametrically changed. With linear AP phase shifts, waveforms of the response are unchanged but the time delays appear. With nonlinear AP phase shifts, waveforms of the response show irregular attenuation, and their maximum amplitudes are smaller than the original ones.

著者

小塩 達也 O'Brien Eugene Taylor Susan

出版者

公益社団法人 土木学会

雑誌

構造工学論文集 A (ISSN:1881820X)

巻号頁・発行日

vol.65A, pp.600-606, 2019-03-15 (Released:2020-01-27)

参考文献数

10

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Weigh-in-Motion measures vehicle load on roadway without stopping traffic. Bridge Weigh-in-Motion (BWIM) uses bridges as a weight scale. The advantages of BWIM are its invisibleness to drivers, low cost and simple installation. This study tested a potential of "Contactless Bridge Weigh-in-Motion" without any sensor in bridge. A digital high-speed camera captured bridge deflection by long distance lens, and another camera captures passing vehicle on road surface. Gross vehicle weight is calculated by influence area method by integration of deflection time history and estimated vehicle speed by traffic image. The accuracy of the BWIM system was under 20% for test vehicles with known gross vehicle weight.

著者

秦 吉弥 矢部 正明 枦木 正喜 高橋 良和 葛西 昭 松崎 裕 秋山 充良

出版者

公益社団法人 土木学会

雑誌

構造工学論文集 A (ISSN:1881820X)

巻号頁・発行日

vol.63A, pp.251-264, 2017 (Released:2018-06-08)

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下記の論文は撤回されました.記秦吉弥,矢部正明,枦木正喜,高橋良和,葛西昭,松崎裕,秋山充良:臨時余震観測に基づく2016年熊本地震における九州自動車道沿いの被災橋梁に作用した地震動の評価,構造工学論文集,Vol. 63A,pp. 251-264,2017.撤回の理由2019年3月15日に大阪大学より公表された研究活動上の特定不正行為に関する調査結果において,本論文に対して第一著者による特定不正行為(ねつ造)が認定されたため,撤回した.

著者

秦 吉弥 中村 晋 野津 厚

出版者

公益社団法人 土木学会

雑誌

構造工学論文集 A (ISSN:1881820X)

巻号頁・発行日

vol.58A, pp.250-263, 2012 (Released:2013-04-19)

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下記の論文は撤回されました.記秦吉弥,中村晋,野津厚:2011年東北地方太平洋沖地震における藤沼ダムでの地震動の評価-海溝型巨大地震へのサイト特性置換手法の適用-,構造工学論文集,Vol. 58A,pp. 250-263,2012.撤回の理由2019年3月15日に大阪大学より公表された研究活動上の特定不正行為に関する調査結果において,本論文に対して第一著者による特定不正行為(ねつ造)が認定されたため,撤回した.

著者

石井 徳章 阿南 景子 巻幡 敏秋 奥 達也 大原 健史

出版者

公益社団法人 土木学会

雑誌

構造工学論文集 A (ISSN:1881820X)

巻号頁・発行日

vol.53A, pp.589-596, 2007 (Released:2007-08-01)

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This paper describes a serious failure of 37-ton Tainter gate in Japan and presents its failure re-investigation, where the major characteristics of static structural strength and self-excited vibration are addressed with the aid of current FEM high technologies and our theoretical calculations developed for the 87-ton Tainter-gate failure at Folsom dam in California. The Tainter-gate failure occurred on July 2nd 1967 at W Dam, constructed at the upstream of Yura River in Kyoto Prefecture in Japan. The failure investigation at that time concluded that the radial strut structure was not high enough in strength for the hydrostatic load to induce the serious in-ward buckling failure of the main radial struts. In the present study, FEM simulations were made to address that the gate failure could not take place, caused only by the static hydraulic load. Subsequently, the theoretical calculations developed for the Folsom Tainter-gate failure was incorporated into FEM simulations to address that W gate also induced the coupled-mode violent self-excited vibration at its incipient failure, while the gate was being closed at small gate openings, closely similar as on the Folsom gate failure.

著者

髙西 照彦

出版者

公益社団法人 土木学会

雑誌

構造工学論文集 A (ISSN:1881820X)

巻号頁・発行日

vol.59A, pp.353-361, 2013 (Released:2014-03-14)

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In order to control vibration on a structure having two degrees of freedom system of swaying and twisting vibrations during harmonic ground shaking, two kinds of tuned system damper are installed on the structure. In this paper, one method is proposed to determine approximate optimum dynamic parameters of these two dampers (optimum frequency ratio, mass ratio of a damper to that of the structure and optimum damping constant). A five dimensional nonlinear simultaneous equation which satisfy conditions minimizing response of acceleration of two corners of structure was deduced. This equation was resolved by using iterative procedure by Newton's method and five optimum values of dynamic parameters were obtained.

著者

小川 一志

出版者

公益社団法人 土木学会

雑誌

構造工学論文集 A (ISSN:1881820X)

巻号頁・発行日

vol.53A, pp.550-559, 2007 (Released:2007-08-01)

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An Impact Mass Damper (IMD) is a simple damping device which consists of a weight and a cushion attached on a tower. It utilizes energy dissipation due to collision between the weight and the cushion on the tower. Considering damping capacity of the IMD depends on the collision, the impact force caused by collision cannot be neglected and it may have a bad effect on habitability of the tower. This paper proposes the new IMD idea which has the lower impact force and the enough damping capacity to suppress the harmful vibration, by investigating the vibration characteristics of the cushion.

著者

大野 友則 橋本 進 中村 弘

出版者

公益社団法人 土木学会

雑誌

構造工学論文集 A (ISSN:1881820X)

巻号頁・発行日

vol.59A, pp.1048-1055, 2013 (Released:2014-03-14)

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In today's turbulent world, civil engineers require methods and guidance on how to design structures to resist various accidents or hostile acts. Due to accidental explosions or bomb attacks on facilities, there is the increased concern for protection of persons on the part of facility owners and facility designers. An exterior mode attack involves the throwing or placing of explosive charges near a facility. The objective of such an attack is generally the destruction of the facility and the social disturbance. In these events, explosive weights are limited to amounts that can be carried by the person. To develop blast resistant techniques, this study is to find experimentally a local failure mode of steel plate due to close-in explosion. In explosive tests, SS400 steel plates with different thicknesses are tested under various conditions. From test results, a perforating limit line for contact and close-in explosion is formulated.

著者

石川 敏之 河野 広隆 長尾 隆史 小林 朗

出版者

公益社団法人 土木学会

雑誌

構造工学論文集 A (ISSN:1881820X)

巻号頁・発行日

vol.61A, pp.808-815, 2015 (Released:2015-05-22)

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In steel members bonded with carbon-fiber reinforced polymer (CFRP) plate, the thermal stresses are introduced in the steel members, the CFRP plates and the adhesive layers when temperature changes because the linear thermal expansion coefficients of steel and CFRP are mismatched. In the previous paper, the authors proposed a technique to reduce thermal stress in steel members strengthened by CFRP plate, which involves bonding aluminum alloy plates with CFRP plates. In this research, the thermal stress introduced in the steel plate with CFRP and aluminum plates was measured over one year. As the result, it was shown the thermal stress in steel plate was neglectable small through the all-season. Additionally, a steel plate bonded carbon fiber strand sheets and aluminium plates side by side was tested. In this method, the thermal stress induced in steel plate was also reduced.

著者

横川 英彰 中島 章典 緒方 友一 青戸 清剛 笠松 正樹

出版者

公益社団法人 土木学会

雑誌

構造工学論文集 A (ISSN:1881820X)

巻号頁・発行日

vol.54, pp.209-217, 2008

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In this research, we examine the reproducibility of the actual dynamic behavior of the simple viaduct model with the pseudo-ground by the dynamic response analysis. First, we conduct the vibration test of the pier and superstructure member, and the movable bearing. Second, we identify the damping property from the experimental results. Third, we construct the numerical model according to the test model so as to reproduce the natural frequency and the damping property of the viaduct model. Finally, we try to reproduce the vibrational behavior with the pseudo-ground by the dynamic response analysis of the numerical model which is constructed on the basis of the finite element method with the rotational spring and dashpot at the pier base. As a result, the dynamic behavior of the viaduct model is successfully reproduced by the numerical model under the earthquake excitation rather than another numerical model considering Rayleigh damping matrix.

著者

広瀬 望 武邊 勝道 大屋 誠 佐藤 誠

出版者

公益社団法人 土木学会

雑誌

構造工学論文集 A (ISSN:1881820X)

巻号頁・発行日

vol.60A, pp.605-612, 2014 (Released:2014-08-01)

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Atmospheric corrosion of the steel surface of a bridge is largely due to salt spays generated over the ocean. The observed data indicate that the salt sprays first adhere to the steel, after which the extent of Cl− on the steel surface increases; however, the mechanism by which these processes occur has not yet been investigated. Our research objectives are to examine the relationship of atmospheric Cl− concentration with the extent of Cl− adhering to the steel surface and to clarify the effect of surface winds on the extent of Cl− adhesion. The results show that the extent of Cl− adhesion is positively correlated with atmospheric Cl− concentration and that the extent of Cl− adhesion depends on surface winds.Therefore, when estimating Cl− on a steel surface, we must consider the atmospheric Cl− concentration and the surface winds.

著者

澁谷 直隆 杉本 博之

出版者

公益社団法人 土木学会

雑誌

構造工学論文集 A (ISSN:1881820X)

巻号頁・発行日

vol.59A, pp.230-243, 2013 (Released:2014-03-14)

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The governments of many communities have been trying to create their bridge maintenance planning. Generally their economic conditions are not good, the low maintenance costs and the smooth annual expenditure are required. For these requirements, the good approximation of the maintenance costs corresponding to the members and the materials of bridges are necessary. And also the real deterioration curves of the members of bridges are required. Some better models of these items are proposed in this paper with the improved GA process and make it possible to formulate the realistic BMS optimization problem. 300 really existed bridges problems are solved and show the effectiveness of the proposed optimization system.

著者

渡辺 勉 曽我部 正道 山崎 貴之 奥田 広之 涌井 一

出版者

公益社団法人 土木学会

雑誌

構造工学論文集 A (ISSN:1881820X)

巻号頁・発行日

vol.53A, pp.77-86, 2007 (Released:2007-08-01)

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Many floating tracks have been used for only low-speed trains as vibration reduction system. A study was carried out on dynamic response and running quality, using various floating tracks for high-speed train. A simulation program, DIASTARS was used in this analysis. In this program, the Shinkansen vehicle is three-dimensionally modeled as having a body, two trucks, and four wheelsets connected to each other by spring and dampers. The floating tracks were modeled by three dimensional finite element methods. In this study, the wheel load variations and vehicle body accelerations were investigated by dynamic interaction analysis between vehicle and track. The parameter was the train speed and the stiffness to support track.