Fundamental Studies on the Earthquake Resistant Design of Bridge Structures

This paper describes an outline on the results of fundamental studies on the earthquake resistant design of bridge structures, on which the author has been working since 1948. At first, characteristics of small amplitude vibration of bridge structures are treated theoretically, and at the same time, characteristics of the large amplitude vibration of bridge structures are studied by model tests. Then, from the results obtained above, a fundamental method of computation is derived for the earthquake resistant design. In this case, however, the method of computation may be true only within elastic limits of structural materials and foundation ground. The method of computation for the non-elastic portion is still being studied

Vibrational Characteristics and Aseismic Design of Sub-merged Bridge Piers

This paper presents the dynamic water pressure on the cylindrical sub-merged bridge piers during earthquakes, and the vibrational characteristics of flexible sub-merged bridge piers. Moreover the authors discuss the damping effect of water and the aseismic design of sub-merged bridge piers consulting the theoretical and experimental analysis

A Dynamical Consideration on Earthquake Damages of Bridge Piers : First Report

As was also noted from the results of the Fukui Earthquake of June 1948, it is now quite evident that the earthquake damage of the bridge substructure decisively affects the damage of the whole bridge, directly or indirectly, with almost no exception. In view of this fact, it is attempted in this paper to make a dynamical study from both theoretical and experimental points of view on the mechanism of earthquake damages of the bridge substructure and thereby contribute to the earthquake-proof design and construction of bridge piers

A Statistical Study of the Maximum Ground Motion in Strong Earthquakes

This paper presents the results of a theoretical analysis of the statistical properties of the maximum ground motions in strong earthquakes. The statistical model of earthquakes is proposed so as to be consistent with the past records of occurrence of earthquakes and with strong motion accelerograms, on the basis of which the methods are discussed to find the probability distribution of the maximum ground motion in a single earthquake and that for a certain future period. Numerical results are given in the form of charts and seismic maps

Analysis of Flexural Behavior and Lateral Buckling of Inelastic Steel Beams under Cyclic Loads

Inelastic steel beams are analyzed with emphasis on their transient flexural behavior and lateral buckling under cyclic loads. The constraint and load conditions are chosen so that they simulate inelastic beams, of a frame structure subjected to a horizontal seismic motion. An analytical model of inelastic beams is proposed that accounts for basic transient behaviors of mild steel. On this basis, a detailed discussion is made on the mechanism of transient behaviors including those of the plasic hinge, loaddeflection relation, lateral buckling load, etc. A physical interpretation is given as regards the transient flexural behavior and the deformation capacity for the lateral buckling of steel beams under monotonic and cyclic loadings

Random Fatigue Analysis of Structural Steel Bars Subjected to Plastic Bending

Low-cycle fatigue life of structural steel bars subjected to random plastic flexural deformation is analyzed. Fatigue tests are performed on 100×100 SS41 H bars under constant-amplitude and randomly varying repeated loads. Fatigue life for random loads is estimated by using the linear cumulative damage law. Damage per unit time (or cycle) is predicted by (1) the equivalent amplitude factor and (2) peak-trough and plastic deformation criteria. Estimated results are compared with test results

Seismic Response Analysis of Joint-Connected Buried Pipelines Including Bent Sections

Response analysis of joint-connected buried pipelines including bent sections has been carried out using analytical models, types of which are commonly used in the actual underground lifeline systems. The details of the structures and materials along the trunk routes of the Kyoto City Water Supply Districts have been intensively examined to establish these analytical models. Response analysis for four representative models of buried pipelines has been performed with some analytical parameters of pipe-structures, input ground motions, and soil springs, etc., focusing on the effects of the structural and input ground motion parameters on the response behavior of pipelines

選択的セロトニン再取り込み阻害薬とセロトニン4受容体作動薬の直腸吻合部におけるインビボ神経再建に与える効果の比較

It was recently reported that activation of enteric neural 5-HT(4) receptors (SR4) promotes reconstruction of enteric neural circuit injury in distal gut of guinea pigs and that this reconstruction involves neural stem cells. We aimed to explore a novel approach using a selective serotonin reuptake inhibitor (SSRI), which increases endogenous 5-HT, to repair enteric nerve fiber injury in the rat distal gut. Enteric nerve fiber injury was performed by rectal transection and subsequent end-to-end one-layer anastomosis. The SSRI fluvoxamine maleate (100 μmol/l) was applied locally at the anastomotic site to compare with the 5-HT(4) agonist mosapride citrate (100 μmol/l) (applied for patent) applied locally and orally. Unlike mosapride, fluvoxamine failed to promote the regeneration of the nerve fiber tract across the anastomosis. Furthermore, fluvoxamine did not generate anti-distal-less homeobox 2 (DLX2)- and anti-SR4-positive cells (neural stem cells) and/or anti-neurofilament (NF)-positive cells (neural cells) in newly formed granulation tissue at the anastomosis, whereas these cell types were observed in mosapride-treated preparations. In contrast to its effects in guinea pigs, mosapride generated 5-bromo-2'-deoxyuridine (BrdU)-positive neural cells in ganglia sites 3 mm oral and anal from the anastomosis 2 wk after nerve fiber injury. All actions of mosapride were observed after local and or oral applications. These findings indicate that local SSRI treatment does not induce in vivo nerve fiber tract growth across the anastomosis in the rat distal gut. Mosapride induces nerve fiber tract growth across the anastomosis, mediated through enteric neural stem cells possibly from neural crest-derived stem cells or mesenchymal stem cells in the bone marrow.博士（医学）・甲616号・平成26年3月17日発行元の規定により、本文の登録不可。本文は以下のURLを参照 "http://dx.doi.org/10.1152/ajpgi.00284.2011