Recently, some methods to utilize the coal ash, that occurs as a waste product of thermal power plant operation, have been investigated. Fly ash fiber, that is produced by fusing coal ash and at high temperature and pulling it into fibers, exhibits high strength, thermal resistance and alkali-proof. Therefore, it was thought that if fly ash fiber could be used in the making of reinforced mortar, precast products of high strength, thermal resistance and durability would result. This report describes test results on the mechanical properties of fly ash fiber reinforced mortar. As a result, it was confirmed that the fly ash fiber reinforce mortar maintained excellent workability, high flexural strength and thermal resistance.

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The influence of polymer modification on the fracture parameters of high-strength concretes was investigated. Fracture toughness test was conducted for various types of specimens which vary the matrix strength, the type of coarse aggregate and the polymer content. Fracture parameters for the high-strength concretes were analyzed based on the poly-linear approximation analysis of the tension softening diagram with the data of load-load point displacement curves. The tensile strength, fracture energy, toughness modulus and crack resistance of the high-strength concretes were improved by adding the appropriate amount of polymer in paste matrixes. The use of polymer was effective in the case of the high-strength concretes containing high-strength aggregate.

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In city area, electromagnetic interference caused by buildings is a very important problem. For example, a well known ghost phenomenon is caused by interaction between incident and reflected waves caused due to the presence of large and tall buildings. The characteristics of the radio waves absorption have been measured by coaxial-wave-guide unit or curtain wall specimens. But these measurements have some demerits. In this paper, a new measurement technique by panel specimen using parallel wire line is proposed and the accuracy of the this technique is verified. An examination of return loss by the fertile concrete panel specimen is carried out. It was shown that the measurement accuracy using parallel wire line and coaxial-wave-guide are almost equal. However, the parallel wire line technique can measure the characteristics of the radio wave absorption without being effected by the electrical environment around.

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The aim of this study is to present a relative evaluation method on hardness and unevenness of floor and road surfaces from the viewpoint of stability of footing applying adults including the aged. First, psychological scale about stability was made by means of the sensory test with 22 sample floors and 46 men and women, 22〜86 years old. Next, physical value of floors measured by our own apparatuses was corresponded to psychological scale. Lastly, the relative evaluation method which contained the relationship between physical value and psychological scale and the measuring method of physical value was presented.

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This paper discusses properties of stress caused by wind pressures acting on stiff two-hinged arches supporting a barrel roof. Wind tunnel test was performed with a turbulence boundary layer wind at geometrical scale S=1/250, which correspond to flat terrain. Models of rectangular low-raise buildings with different raise-span ratios and span-height ratios were used in the test. The following are results of the study, (i) The distributions of mean stress and maximum stress of a stiff arch at the center of a barrel roof, in the same direction as the wind, are similar, (ii) The gust factor of load effects decreases as span ratio increases, (iii) The tendencies of gust factor of load effects are almost same as for flat roofs, (iv) The distributions of mean stress and maximum stress in the stiff arches at the gable ends are different when wind direction is parallel to the span and when wind direction is perpendicular to the span, (v) The stress behavior of stiff arches depends on the fluctuation of wind pressures acting on the barrel roof.

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It is important to estimate effects of deep subsurface structures to long-period ground motion. In this study, the mean subsurface structures between a observatory at Kashiwazaki, Niigata prefecture and epicenters are estimated as a multi-layered model by an inversion of the group velocities using a genetic algorithm. The estimated models for the events located around Niigata have deep pre-Neogene basement and the depth of basement estimated from the epicenter near Toyama trough is especially deep. These features of the models agree with the regional variation of geological data and gravity anomaly. Furthermore, long-period ground motions at the observatory are evaluated by normal mode theory using the estimated models and existing fault parameters. Over whole features of the records were reconstructed by synthetics. It is concluded that the subsurface structure estimated from single station data is so useful to evaluate long-period ground motions.

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It is presented an analysis of mullistoried slab-column structures subjected to lateral loads. The structures under consideration consists of slab, columns, and extension of the slab beyond the support line as a cantilever. Reissner's plate theory is applied to slabs, and Timoshenko' s beam theory to columns. By using the method super- impostion , it is shown that solutions which satisfy identically the differential equation and which satisfy the boundary conditions with any desired degree of accuracy are obtained. Numerical results are compared with those of equivalent frame method by using the effective plate width.

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In constructing a 256-m-high skyscraper on a reclaimed land, there are two problems awaiting solution; one is negative friction of piles due to consolidation settlement of alluvial clay layer under the reclaimed soil layer and settlement of diluvial clay layer locating deeper than the bearing stratum of the building. These were handled in conducting subsurface exploration, foundation design, study on construction methods and construction work at the site controlled by measurements. Land settlement due to construction of a building should be estimated not only by evaluating increase in load and volume compressibility but also by considering 1) changes with time in ground-water table during excavation work and 2) load re-distribution effect due to rigidity of superstructure as a whole

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The pnipose of this paper is to explain the deformation of cantilevered cylindrical shells subjected to transverse end loads at its tip by means of geometrically nonlinear theoretical three-dimensional analysis. As a result, it is clarlified that the deformation of the cross section is mostly caused by the bending moment. Using this result, we also propose the analytical method to calculate the local budding stress in consideration of both the deformation of the circular section subjected to the bending moment and the effect of the restriction of the deformation at its tip. In comparison with experiments on buckling stresses, the proposed method gives the proper upper bound of the backling stress.

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Space structures can be said to be correctly designed if they are found to resist against external design loads mainly through their strong capability for membrane stress resultants. Up to now, there have been several attempts to create the bending free shapes which enable us to realize rational shapes for space structures and shells both experimentally and theoretically such as the works by H. Isler, N. F. Ortega and our previous researches as well. Present paper deals with minimization process by which bending free surface for shell structures can be directly obtained through application of the nonlinear programming technique for the objective function which is composed of bending moments components. Axisymetric shells are shown as numerical examples, where effectiveness and usefulness of present treatment are clearly appealed and some investigations on the mechanism through which bending free structures are created are also discussed.

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Five 5/9 scale reinforced concrete columns with reinforcement details typical of concrete buildings designed before 1981 were constructed and tested under high speed loading. Three columns have the shear reinforcement with 90 degree end hooks and their seismic performance were compared with those with 135 degree end hooks. The seismic behaviour of the columns with plain round bars for the longitudinal bars were also compared with those with deformed bars. It was found that the 90 degree end hooks were not effective for the shear reinforcement under seisimc loading and that the seismic behaviour of the columns with plain round bars for the longitudinal bars were different from those with deformed bars.

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Compression-bending tests and compression-bending-shear tests of R/C columns were carried out. Compression was constant and bending/bending-shear was monotonic. The bending moment in compression-bending-shear test was antisymmetric along the column axis. The compressive strength of the concrete ranged from about 300kg/cm^2 to about 600kg/cm^2. The compressive behavior of the concrete around the critical section of R/C column was evaluated by using the compressive stress value k・σ_B of equivalent stress block. The following conclusions were obtained. 1) The value of kmax under compression-bending-shear is larger than that under compression-bending. 2) The value of kmax under compression-bending-shear is affected by the history of compression-bending combination. 3) The value of kmax is little affected by compressive strength of concrete σ_B. 4) The value of k under compression-bending-shear is stable.

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Strength, rigidity, capacity of elongation, bond stress-slip relations etc. of grout-filled coupling steel sleeves with interior projections under cyclic loads were investigated. Experimental variables adopted in this study were development length of reinforcing bars, compressive strength of grout as filler materials and magnitude of cyclic loads. Following main conclusions are obtained (1)Mechanical performance of the splices subjected to cyclic bad is improved significantly with increase in development length of reinforcing bars and compressive strength of grout (2)Assumption of constant bond stress between grout and reinforcing bars in the splices leads equations to estimate strength and failure types of the splices.

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The effect of ground motion on a building is taken as energy input, and is absorbed as structural damage during strong earthquakes. The relation between yield strength distribution and damage distribution has already been determined experimentally by numerical analysis. The purpose of the present study is to contribute an analytical examination of the damage distribution law of the multi-mass shear system. By considering the resonance response of stiff-perfectly plastic multi-mass shear system, the author develops a theoretical damage distribution law, and shows that it is in accord with damage distribution laws previously proposed.

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The basic condition of limit state design for beams is that beams show sufficient plastic deformation capacity by generating plastic hinges at the beam ends. Concerning beams with web perforation, this condition is also satisfied when opening located in a distance from the beam end is not dameged prematurely. In this paper, design formulae for evaluating strength of opening part and limit distance of the opening from the beam end are proposed. And an experiment was performed for verifing the propriety of the design formulae and the plastic deformation capacity of the beams with web opnenings.

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In order to evaluate the ultimate earthquake resistance of multi-story steel frames influenced by the rigidity of column bases, a series inelastic response analysis on steel moment frames with the realistic characteristics of steel members was carried out. Conclusions are summarized as follows; 1) When the rigidity of column bases becomes loose, damage concentration on the lower end of columns of the first story decreases accompanying the increasing of damage in upper beams and panels. 2) The ultimate earthquake resistance of the steel moment frame improves with decrease of the rigidity of the column bases.

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The objective of this paper is to propose a refined strength formula of slender concrete filled steel tubular columns. On the basis of experimental results, current AU design formula is examined, and it is found that the supposed strength of a concrete column is so conservative when the buckling length-section depth ratio becomes large. Accordingly, an elasto-plastic analysis is performed to obtain the concrete column strength. After the concrete column strength is proposed, to use the concrete strength instead of the supposed strength is proposed in the current AIJ design formula. It is shown that experimental maximum load is well estimated by the proposed method.

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As witnessed in Kobe during the 1995 Hyogoken-Nanbu Earthquake, the collapse of building structures causing human deaths resulted mostly from poor engineering. Such unsatisfactory engineering in building construction came from lack of knowledge on structural behaviors, not necessarily from ethical morals of engineers. Japan is one of the most advanced countries in construction engineering, but the basic knowledge as well as the high technology is not distributed into the base of the construction industry. Indeed, it is certain from fact-finding study that most of low-rise buildings in Japan are engineered by the engineers who graduated from technical high-schools, where the educational curriculum on structures is not enough not only in assigned credits but also in teaching staffs and aids. It is agreed by the high-school teachers that experience-based education by means of visual experiment is very important to help the students to learn structural theories. Thus, the distribution of experimental equipment and the strengthening of teaching staffs on structural education in technical high-schools must be firmly promoted, and advanced courses on structural education after high-school graduation must be established in view of lifelong education.

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This report proposes a practical minimum weight design method controlled by the structural performances which the structural engineer specified, and estimation method of other structural performances, for elastic 3-D steel frame. This method is based on Nakamura-Kosaka's strain controlling theory and uses neural network training and non-linear planning method . This method will be effective tool for structural engineer in structural planning stage, because this method can grasp on the structural cost and structural performance easily. This report shows that neural network is an effective tool for the inverse design problem which is difficult to expand theoretically, using the examples.

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