To evaluate the seismic behavior of railway bridges supported by isolation rubber bearings, it is important to clarify the dynamic interactions between the continuous track structures and the bridges. Shaking table tests were implemented with a part of real size slab track structures and the dynamic constraining force by the track structures during the earthquake was investigated. Then a non-linear hysteresis model of that constraining force was proposed. Furthermore, the effects of the track structures on the seismic behavior of bridges were studied by nonlinear dynamic response analyses with the use of the proposed model. As a result, it was confirmed that the seismic response of the bridge piers and the rubber bearings vary about 10 - 20% with the effect of track structures.

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 Fatigue cracks along cutouts of diaphragms or transverse ribs in orthotropic steel deck have been reported. Various alternative cutout details have been proposed. However, most of them result in the poor fabrication performance or insufficient fatigue resistance. This study examined the fatigue resistance of the cutout changing the geometrical shapes and dimensions, and a series of finite element analysis was performed with minute shell and solid elements. The improved cutout details release the stress concentration by approximately 75% compared to the conventional ones. In addition, fatigue tests on the full scale specimens were carried out and the test result demonstrated that proposed cutout details significantly improved the fatigue resistance.

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 The design method of the beam-to-column connections of steel rigid frame piers is not specified concretely in the Specifications for Highway Bridges and is conventionally in compliance with the design standards of expressway companies. However, as this is an elastic design method that takes into account local stress concentration caused by shear lag, this method can decrease construction workability and economic efficiency by making the beam-to-column connections heavier than the general part of the beams and columns. In addition, it has yet to be proven that this method is applicable in the case of large-scale earthquakes.
 This is the background to our carrying out a series of studies to establish a new method for designing beam-to-column connections by clarifying their load-carrying capacity and elasto-plastic behavior.
 This paper summarizes, further examines and organizes the knowledge acquired through a series of studies and proposes a design method for beam-to-column connections that takes into account their elasto-plastic behavior and the effects of fillets, as well as verifying the applicability and effectiveness thereof through the trial design of an actual structure using this method.

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 We carried out centrifuge tests to clarify the seismic behavior of batter-pile foundations. A vertical-pile foundation and a batter-pile foundation without the presence of a superstructure were installed parallel to each other in a soil container filled with dry sand, and were excited simultaneously. Through a comparison of the acceleration and displacement response of the footing, as well as the axial and bending strains of the piles for the two pile foundations, the nonlinear kinematic response of the seismic behavior of the batter-pile foundation was experimentally investigated.
 The main conclusions of the study are as follows:
1) The response of the footing of the vertical-pile foundation to motion to the right is clockwise rotation. On the other hand, that of the batter-pile foundation is rotation in the opposite direction to that of the vertical-pile foundation.
2) The aseismicity for the horizontal acceleration of the footing can be improved by using batter piles in almost all frequency ranges.
3) Bending and axial strains of the batter-pile foundation are larger than those of the vertical-pile foundation. In other words, batter piles require large cross-sectional capabilities to compensate for their aseismicity.
4) The effect of the aseismicity of the batter-pile foundation increased and the bending and axial strains at the pile head of the batter pile approached those of the vertical pile as the maximum acceleration of the input motion increased. These phenomena are considered to be related to soil stiffness reduction induced by soil nonlinearity.

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 One of corrosion forms in beam ends of steel bridges is loss of the web thickness. Re-corrosion in a few years has been detected occasionally on the cover steel plate to recover the web cross section which is a conventional repair/reinforcement method. In this research, spraying rubber-latex mortar on the both sides of the corroded web of a steel I beam is proposed and the reinforcement effect is confirmed by vertical loading tests. Furthermore, FEM analyses are conducted to evaluate increment of stiffness, yielding load and load carrying capacity of reinforced beam with the rubber mortar. Finally, a design method for the necessary thickness of rubber latex mortar is discussed.

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 In this research, to study mechanical behavior of a steel pier which four steel pipes are connected by shear hysteresis dampers made of low yielding steel, experiments and FE analyses were carried out. The experiments were conducted by four loading patterns which were monotonic torsional moment loading, cyclic loading under fixed axial force, and cyclic loading under fixed axial force and torsional moment. The experimental loading pattern models were also analyzed by finite element method. In addition, the parametric analyses were executed, which parameters were the amount of torsional moment, the loading direction and the width thickness ratio of the web panels. The results provided beneficial knowledge for design of the steel pier taking into the effects of account the torsional moment and shear plate buckling.

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 In this paper, influence of number of rows of bolts and plate thickness on slip resistance is discussed with slip resistance tests. Slip tests of high strength bolted friction type joints painted by inorganic zinc rich were carried out with test specimens which have combinations of 38/50/75mm thickness plates and 3/8/12 rows of bolts. As a result of these tests, it was observed that all specimens had slip coefficients over 0.4 which is specified in the current deign code and the slip resistance of the 12-row-specimens decreased approximately 7% compared with 8-row-specimens.

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 Wind loads, which are known to be an essential factor in the design of structures for photovoltaic arrays, can be obtained from the product of kinetic pressure, wind-force coefficient (C_W) and array area, under JIS C8955. However, usage of C_W is limited to an array angle-of-attack (θ) between 15 and 45 degrees, and is not applicable where angle-of-attack is low (θ=approx. 10 degrees). However, such low θ are being used increasingly in recent years. In addition, when objects having a wing-form shape are moving close to the ground, a ground-effect may arise, resulting in an increase in lift power. The impact on the ground effect due to the distance between the wing-shaped form and the ground, that is the height of an array structure above the ground, has not been examined up until now. By taking these factors into account and properly estimating wind loads, it will be possible to ensure safety and economical performance of arrays. In this research, the authors conducted a wind tunnel test using a 1/20 scale array model to estimate and refine C_W taking into account the array's angle-of-attack and its structure height. Favorable results were obtained through this research.

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 A lot of kinds of the welded joints are employed in steel structures, and transverse butt welded joints are the most fundamental ones. In case that the joints have lack-of-penetration, the fatigue strength drastically decreases. In fact, there are some cases that the fatigue damage has been detected due to the lack-of-penetration. Therefore, some researches have been done about the fatigue strength of the transverse butt joint with the lack-of-penetration. However, fatigue strength of the joints with weld reinforcement in addition to the lack of penetration has not been made clear yet.
 In this study, in order to make clear the fatigue strength of the transverse butt welded joints and propose the fatigue strength evaluation expression for obtaining the fatigue strength, fatigue tests and fatigue crack propagation analyses have been carried out on model specimens and analytical models with various shape and size of reinforcements, length of lack of penetration and plate thickness.

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 Many bridges were washed away by the tsunami that followed in the wake of the 2011 Great East Japan Earthquake. This research experimentally investigated a hydrodynamic measure that involves adding baffle plates to the bridge girders. Vertical, inclined and semicircular baffle plates were added to the sides of the bridge girders. The hydrodynamic force acting on the girders was measured, and the flow pattern in the vicinity of the girders was observed. A plate girder bridge with 4 I-girder model experienced large horizontal and vertical upward force during the simulated tsunami. The results showed that the vertical force acting on the bridge was reduced by adding baffle plates, which decreased the risk of the bridge being washed away. Influence of ice with the tsunami wave was also considered.

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 As for on-site of the maintenance and strengthening work for steel bridges, the high strength bolted friction type joints are often applied. But, the surface preparation of the existing steel member may not be able to be processed abrasive blast-cleaning depending on site conditions. Therefore, the slippage tests were carried out using splice plates processed the inorganic zinc rich paint on surface and connected plates varied surface roughness on surface. As a result of the slip test, it was found that the slip factor and surface roughness have a linear relationship up to painted 75μm thickness of inorganic zinc-rich paint. And it is proposed that in case that painted 50μm~150μm thickness of inorganic zinc-rich paint, the slip factor is 0.4 in case of Ra (arithmetic mean estimation) > 5μm, but it is 0.2 in case of Ra < 5μm.

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 There were the following typos in the article, "Journal of Japan Society of Civil Engineers, Ser. A1 (Structural Engineering & Earthquake Engineering (SE/EE)) Vol. 69 (2013) , No. 2 pp. 372-391"

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