The influence of concrete curing time on the fracture parameters of plain concrete and short cut fiber reinforced concrete was investigated. Three-point bending tests on pre-notched concrete beam specimens were performed. Fracture parameters of specimen were analyzed based on the poly-linear approximation analysis of tension softening diagram with the data of a load-load point displacement curve. It was found that the critical load-point displacement got small with the increase of curing time and of concrete strength, the fracture energy of normal strength concrete was almost same as that of high strength concrete, and the fracture energy of the short cut fiber reinforced concrete became greater with the increase of curing time and of concrete strength. Tension softening diagram of short cut fiber reinforced concrete were approximated by tri-linear, using effective tensile strength, effective fracture energy and stress at 0.5mm crack opening displacement in poly-linear tension softening diagram.

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Permeability of placing joint of cement mortar during casting was measured for the specimens placed at various interval times by using kerosine as permeation liquid instead of water, and a water path in the specimens was observed. The longer placing interval time of the two mortars, the easier liquid leaked through the placing joint. The pore structure was furthermore measured at various positions including placing joint in the specimens by a mercury intrusion method. Pore volume at placing joint is clearly much compared to the other area in the specimen. It is concluded that the existence of porous zone at placing joint results in an increase of permeability.

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For the purpose of developing a model for predicting the bending strength of glued laminated timber (glulam) beam, the resistance mechanism and fracture process were examined experimentally. Ninety glulam that consisted of various conditions were analyzed. Here the conditions were difference of beam depth, lamina thickness and lamina composition. Though the fracture process was complex, it is necessary for the predicting model for reproducing fracture process to consider fracture of lamina at many parts, progress of cracks and partly cracks. Four suppositions that have to be taken in predicting model were made clear through comparison between this experiment on glulam and previous experiment on lamina.

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Preventive capabilities of repair methods against salt damages to reinforced concrete structures were studied by comparing three different repair materials. Surface covering and chipping-molding repair were applied and subjected to an accelerated test and outdoor exposure test for 10 years. The preventive capabilities of these methods were compared in terms of the rate of corroded area and the rate of corrosion weight loss of the reinforcing bars. It was proven that the chipping-molding method extending over the backside of reinforcing steel using SBR polymer cement mortar with a corrosion inhibitor was effective while the surface covering method was applicable when the amount of chloride in concrete structures was excessive. The rate of corroded area of reinforcing steel repaired with the chipping-molding method was relevant to parameters such as duration of acceleration, amount of chlorides, type of repair material, use of inhibitor and water-cement ratio of concrete, while that repaired with the surface covering method was relevant to the duration of acceleration, amount of chlorides and use of inhibitor. The rate of corroded area may be predicted with these parameters.

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The author experimented to make the following relation clear about the external wall which is finished with the tile, the kind of tile, the condition of the removement, the environment at taking a thermograph, the wavelength of thermo-camera and the characteristic of the thermographs and the precision to distinguish removed parts. By the experiments using the test walls, the following item became clear. (1) The removement of tiles and the removement of fundamental mortar differ in the temperature response speed to the change of solar radiation. (2) As for the walls without solar radiation, it is possible to apply the thermography method, but it is rather unclear. (3) When the solar radiation lashes to the wall, as dark as the color of tile, it is easier to distinguish the removed part. The distinction precision by LW machine is better than the SW machine, when noise is small. (4) When the solar radiation doesn't lash, the wavelength influence to precision of distinction. On the LW machine, when taking the thermograph luster tile, the precision of distinction declines by the noise. (5) It is necessary about 1.0 ℃ to distinguish the shape of the removed part when the solar radiation lashes, and about 0.5 ℃ when the solar radiation dosen't lash. The removment of tyle can be distinguished with smaller temperature difference than removment of mortar. (6) The SW machine is influenced by the reflection of the sun and the contrast of the sunshine and the shade. The LW machine is influenced by the object such as the sky and the opposite building. (7) The author ordered apply-ability for each measurement wavelength, in the thermography method.

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The purpose of this study is to present a quantification method of visibility of glasslike opening materials in case of watching a person in a room from the outside. At first, we constructed psychological scales by sensory tests. Secondly, we obtained distribution data of relative luminance from images of the opening materials under the condition of setting a black and white panel as the object. As a result, we extracted physical quantity from the data and we showed the possibility of expressing visibility of glasslike opening materials.

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The load and resistance factor format is one of the practical format for the reliability based design for structures. However, it is generally difficult to calculate those factors, because loads should be treated as a time dependent random variable with a skewed probability distribution function. In order to calculate those factors more conveniently, this paper shows a simple method which can evaluate them considering both time dependency and skewness of random variable, utilizing the load coincidence method and the third moment method.

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Evaluation of aerodynamic instability when wind blows aslant to a building has become increasingly important with progress in aerodynamic control of buildings. However, no evaluation method has yet been established for this case, although an evaluation method has been proposed for the case where wind blows normal to a prism. This proposed method uses a vibration-induced wind force coefficient as an index. This paper proposes an evaluation method for a vibration-induced wind force coefficient when wind blows aslant to a square building with and without a corner recess. The variation of vibration-induced wind force coefficient (Cf) with wind direction is clarified. Furthermore, variation of negative aerodynamic damping ratio with wind direction is clarified by transferring CI to it. The evaluation method is confirmed by comparing vibration tests results and negative aerodynamic damping ratios. It is thus confirmed that the proposed method can be applied to evaluate the occurrence of aerodynamic instabilities when wind blows aslant to a square type building.

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The present study deals with the system reliability evaluation of multi failure mode systems by application of the second-order bounds method which guarantees practical convergence of reliability, particularly, in case of prominent failure modes approximately in parallel with inefficiency of numerical simulation. Practical activity of the present method is positively discussed on numerical comparison between the ultimate limit state and the serviceability limit state of six story, two span rectangular frames.

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In this paper, based on vibration tests of a conventional wooden house with base-isolation devices that were newly developed for light-weight building, base-isolation efficiencies of specimen and seismic behavior characteristics of slide-type base-isolated building were examined. The leading results are as follows. 1) The specimen has enough base-isolation efficiency. 2) Vertical seismic motion has almost no effect to horizontal response displacement. 3) Maximum response displacement under two-way seismic motion nearly agrees with that under one-way seismic motion on principal axis of input velocity.

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We discussed characteristics of pressures and external forces acting on laminated rubber bearings supporting slender buildings subject to seismic horizontal ground motions by numerical simulations. A prediction method of maximum pressures acting on the rubber bearing during uplift caused by the horizontal ground motions was proposed from the above discussion and the sway-rocking model of which the rubber bearing does not degrade vertical stiflhess under tension. The accuracy of the proposed method was examined with numerical simulations. It is found from the results that the proposed method predicts the maximum negative pressure and the maximum positive pressure with enough accuracy.

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This paper discusses the changes brought about dynamic characteristics of floor structure and human sensitivity to vibration by differences in the damping performance of floor structure. For this study, the vibration tests of floor structures fitted with tuned mass damper were performed. From the test results, the tuned mass damper improves the damping effect of floor structure, and suppresses the overlapping and amplification of floor vibration caused by walking. Floor structures with smaller natural frequency receive greater controlling effects and the analytical results correspond well to the test results. Vibration level (JIS C 1510) and maximum converted acceleration are useful guides for evaluating human sensitivity to vibration.

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A new system identification technique using cross spectrum of ARMA model is presented to estimate modal characteristics of buildings from microtremor records. By using this method, one can identify modal characteristics of buildings with soil-structure interaction, where mode shapes and damping factors are estimated accurately from the building response record excited by wind forces as well as ground motion. Moreover, the modal characteristics are able to be separated accurately from one another. In this paper, we derive the theory of this technique, and demonstrate its applicability through numerical simulations for a SR model.

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This paper presents principal solutions of connecting spring and damper systems for optimum vibration control method under several criteria. These solutions are derived from the theory of stationary points of transfer functions defined as displacement response under each component of ground motion; displacement, velocity and acceleration. The model is defined as a pair of one-mass systems connected by a spring and a damper. Two controlling cases are defined; one case in which only the main structural system is considered as the controlling target, and another case in which both structural systems are considered. It has been difficult to solve the problem of controlling both structural systems. This paper presents a systematic method to solve this problem. It has been well known that there exist the stationary points of transfer function independent of the connecting damper. This paper newly shows the existence of the stationary point independent of not only connecting damper but also connecting spring. And the existence of stationary point has important significance for vibration control.

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Input motion of an actual embedded foundation subjected to spatially variable seismic ground motions can be simulated by using the spatial averaging procedure of free-field ground motions considering random (spatially incoherent component) and deterministic(time delay along the propagation path) effects. The simulation results are discussed by the records of earthquake observations and the data of excitation experiment. The conclusions are summed up as follows: (1) The horizontal-translational component and torsional component calculated from the realistic spatial-correlation model of ground motions at the site, almost agreed with the actual records of thirteen earthquake events. (2) The amplitude characteristics of translational component estimated from the spatially variable motions shows the reduction of 20 percent at the frequency of 8Hz in comparison to the characteristics due to uniform S-wave vertical incidence.

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The foundation system is determined depending on the type of structure and soil characteristics. When the bearing layer exists in deep, the pile foundation is generally employed. The wall foundation is combined, when the more rigid performance of foundation is required. Although it is basically prohibited, the composite foundation is sometimes employed as the bearing layer has steep slope condition. The structure on the composite foundation is subjected to the rotational and torsional input motions not only the horizontal motion. The rigorous method should be applied to evaluate the seismic safety of foundation and structures. The improvement of convergence problem due to the internal damping make the explicit method be more useful to the dynamic analyses for the large 3-dimensional models. The developed implicit-explicit hybrid analyses method is applicable to the soil structure interaction models and can predict the dynamic behavior of complex composite foundations. The nonlinear analyses of RC building on the composite foundation is carried out by the proposed 3-dimensional analysis method

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If we joint two glued laminated timbers using finger joint as the grain of these members being parallel, we have a lot of experimental data on mechanical property of these members with finger joints. But, the mechanical property is not yet clarified when the grain of two members are not parallel. We conducted some experiments on moment resisting finger joint of glued laminated timber and phenol FRP, and examined the mechanical property of the latter. In this paper results of tension tests and bending tests of glued laminated timber and phenol FRP are described.

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It is useful to arrange unevenness, like surface roughness or shear key, on joint of precast concrete structure for transferring shear force. But the boundary of shape between surface roughness and shear key is not clear. This study has been carried out to make clear that boundary from viewpoint of a pattern of shear failure. From the past studies performed by the authors, it has become known that the ratio of foot length to height of unevenness, as recognized generally, was more than five. And it has become known too that there are two groups of unevenness like a right-angled isosceles triangle however they have the same ratio of the foot length to the height, one group is considered as surface roughness and the other is as shear key. As a result the authors has made clear the boundary between surface roughness and shear key.

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This paper proposes a seismic retrofitting technique for existing R/C buildings by attaching steel bracing frames to the columns projected from the exterior walls of buildings. Two types of the experimental parameters were focussed in this paper. One is the joint technique between the retrofitting steel columns (beam) and the R/C column (beam). The other is whether or not to anchor the base of the steel columns to the foundations of R/C frames. The cyclic lateral loads were applied to the model specimens, which were about 1/3 the size of R/C frames in school buildings under a constant axial load in the experiments. The experiments and the analyses leaded the following conclusion. The full lateral load carrying capacity was developed in all the specimens regardless of the joint techniques between the steel frames and the R/C frames if the bases of the steel frames were anchored to the foundations of R/C frames. However, the R/C columns failed in shear if they were not anchored.

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Many of previous studies regarding main reinforcing steel bars (rebars) lap splice describe the respective rebars as being lapped side by side (horizontal splicing). The case of lap splice in which the respective spliced rebars are lapped by placing one on top of the other (vertical splicing), as used in precast shell form system, etc., are still not too clear. In order to comprehend the bond splitting strength of vertical splicing, a pure bending test was conducted. The test parameters were the transverse reinforcement ratio and existence of inner supplementary tie. As the result, the effect of transverse reinforcement on bond splitting strength of vertical splicing was about twice of horizontal splicing. An equation was obtained regarding the bond splitting strength of vertical splicing that reflect the difference with the horizontal splicing.

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Expressions for limiting vertical forces acting on beam-columns and beams were proposed first in order to control the cumulative damage of steel frames. The expressions were derived from a condition for stopping the progress of cumulative damage in frames. To verify the validity of the proposed expressions, one-story and two-story steel frames were analyzed by finite element method. Analytical results show that the proposed expressions are useful for controlling the cumulative damage of steel frames subjected to a repeated horizontal loading such as a seismic force. In addition to that, a design method of separating structural elements supporting a vertical force and those resisting a horizontal force is proposed to control the cumulative damage of frames. Some prototype steel frame models designed by the method are analyzed numerically, and the resisting performance and the stability of the frames with the accumulation of damage are discussed.

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Of the beam-column frames which are used in vibration-controlled structures, we conducted repeated static and dynamic tests on the model of flange plates at welded beam-end, using steel type and ambient temperature as parameters. As a result, the following conclusions were obtained. 1) While the transverse stress distribution is convex in the elastic zone, it is reversed into concave in the plastic zone. 2) The higher the strength of steel, the smaller the cumulative plastic deformation magnification. However, all test specimens are fully capable of accommodating the damage which they sustain during the period of using a building. 3) The rise of yield strength due to ambient temperature and test speed is more pronounced in low-strength steels. 4) From the viewpoint of the right steel for the right place, SM490A and SN400A are the most suitable for vibration-controlled structural frames with damners as they fully meet requisite performances.

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This study aims at clarifying the characteristics of the effects of vertical ground motions on seismic responses of steel frames. The inelastic response of multi-story frames is characterized mainly by the restoring force of the lower parts of the frames. The vertical-motion-induced varying axial force affects the response of frames with weak columns to a greater degree than those with weak beams. Therefore, the effects of vertical motions were investigated by conducting on-line tests and numerical analyses using steel beam-column models which represented the behavior of the lower part of frames. It was clarified that the effects of vertical ground motions on earthquake response are small when the ratio of natural period in a vertical direction to that in a horizontal direction is 0.2 or less.

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In the previous article, a design criterion to prevent the premature rupture of beam-end flange of beam-to-column moment resisting connection, in which beam flanges and web are both welded to the column face, was presented. In this paper, the maximum moment resistance and the plastic rotation capacity of the beam-to-column moment resisting connection, in which beam flanges are welded to column through the continuity plates and web is connected to column face by bolts, are analysed and a criterion to prevent the occurrence of connection rupture until the beam develops its own plastic rotation capacity is presented.

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We carried out the tension and compression loading tests of the steel tube filled with the expansive concrete. The results of these experiments may be summarized as follows: (1) This tube may keep very high stiffness under a high tension or high compression load owing to the chemical prestress. (2) The apparent axial initial stiffness of the concrete in the tube is about 2〜2.5 times the Young's modulus of the usual concrete and independent of the prestress value. (3) The apparent tensile strength of the concrete in the tube is mostly depend on the prestress in its higher range. (4) The apparent compression strength of the concrete in the tube is more than 40MPa even if the steel tube is under the yielding.

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New methodology using log-normal distribution was introduced in order to predict wind resistance of plate float glass in buildings based on failure probability theory. New glass surface strength parameters were obtained for reliability design mainly to failure probability 0.001 from 1926 samples of 6, 8, 10, 12, 15 and 19mm thickness. The validity was assured by comparison between experimental results of fracture tests and calculations for rectangular glass under uniform pressure. We presented new wind pressure design charts. The parameters of the charts are the aspect ratio and the glass area. The results showed that the design pressure of some cases was less than that of Notification No.109 by the Ministry of Construction.

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With the increasing of requirement for atrium and public space in architecture, various glass facades have been constructed. The sense of transparency is pursued not only for glass material itself but also for its supporting system. Instead of traditional glass supporting system with mullion and sash, the combination of cable truss and "Dot Point System" recently become popular as a glass supporting system. This paper reports the new glass supporting system named "MJG (Minimum Joint Glazing)" instead of these Dot Point Systems. MJG is the system using a clamp which is able to pinch four glass panels at their corners with no hole, proposed by J. Schlaich. This new system is expected to product more attractive and transparent glass facades. This paper proposes a design method for glass panel by carrying out both experiments and analyses on the following items. (1) Structural characteristics of glass panel under wind-load. (2) Following behavior for out-of plane and relative story deformation of glass panel. (3) Proposal for new glass supporting structures considered of joint performance.

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The importance of logistic system is not widely recognized in Japanese construction industry. Physical distribution and its cost of the materials used for the construction project, therefore, have not been investigated. This report describes estimated transportation cost based on investigations of the transportation vehicles which bring in and out materials for construction sites. And evaluates the impact for improving productivity of the industry. The investigations shows that four to five vehicles transport materials in a day and fifty-seven to sixty-seven percent of loading capacity of the vehicles in volume are used. Estimations show that five to ten percent of construction cost are spent for the transportation based on the hiring cost of the vehicles. Studies on construction logistics, as the conclusion, should be carried out as the one possible solution for improving productivity for construction projects.

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