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Article type: Cover
1978 Volume 265 Pages
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Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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Article type: Cover
1978 Volume 265 Pages
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Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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Article type: Appendix
1978 Volume 265 Pages
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Published: March 30, 1978
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Article type: Index
1978 Volume 265 Pages
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Published: March 30, 1978
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Article type: Appendix
1978 Volume 265 Pages
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Published: March 30, 1978
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MOOHAN KIM, TAKASHI YOKOYAMA, MASAYUKI TABATA, YOSHIRO KOH, EIJI KAMAD ...
Article type: Article
1978 Volume 265 Pages
1-10
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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Laboratory freezing and thawing tests were performed to undertake to provide comprehensive laboratory data on air entrainment which influence to frost resistance of normal weight aggregate concrete at early ages. And it is the aim of this study to present qualitatively and quantitatively a suitable air entrainment which is valid and necessary to prevent the early frost damage of normal weight aggregate concrete by comparing and investigating air content with the other factors influencing to frost damage of concrete at early ages. On the basis of these test conditions, the following observation and conclusions would appear to be warranted; 1. The use of intentionally entrained air results in an excellent effect in frost resistance of concrete at early ages. In case of normal weight aggregate concrete, the adequate amount of intentionally entrained air was found to be 4 percent or more of nominal air content in placing concrete, which is enough capable to get the inferential strength ratio of 80 percent or more after 5 cycles of freezing and thawing, and it is very clear that there is a correlation between air content and early frost resistance of concrete. 2. The influence of freezing temperature, freezing and thawing cycles and kinds of aggregate are not to be compared with intentionally entrained air in the effect of early frost resistance of normal weight aggregate concrete. 3. The strength and water cement ratio give comparatively a corresponding influence in frost resistance of concrete at early ages, while slump give little influence in frost resistance of concrete at early ages. 4. The restoration of strength after early frost damage is to be increased by the curing in water and humid air, but it is considered in actually impossible to expect in practical structures.
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OSAMU ISOBATA
Article type: Article
1978 Volume 265 Pages
11-18
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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A new constitutive model for concrete under multi axial stresses is proposed in relation to the nonlinear stress analysis of the concrete structure by the FEM. An anisotropic formulation is shown by introducing parameters concerning Young's modulus and Poisson's ratio so as to satisfy the reciprocal theorem. Linear relationship of the incremental stress and strain is used by the assumption that the axes of anisotropy are chosen in the principal stress directions and the parameters are represented as the function of the strains in those directions. The fracture condition of the mathematical model consists of the tension cut-off and the octahedral shear failure criteria. The stress-strain relationship of the biaxial compression tests is discussed to determine the values of parameters. And the numerical method is applied to the two ultimate pressure tests on the scaled model prestressed concrete pressure vessels to discuss the compatibility of the measured and calculated data.
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REIJI TANAKA
Article type: Article
1978 Volume 265 Pages
19-31
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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Recently, many high strength steel bars are used in the reinforced concrete members. But, there are no studies solved this question "How high strength steel bars can be utilized effectively in the R.C. members?". Solving this question is very important to development of high strength steel bars. This study gives an anser to this question. First, this study proves that the steel strength could be utilized effectively in the R.C. members, have a upper limitation, and that the upper limitation is restricted by the following valuable conditions. Secondary, in this study, the upper limitation restricted by the following conditions is analyzed by a theolitical coluculation. Valuable conditions considered in this study are written (1) Flexural failure of the beam and column cross-section. (2) Flexural ductility of the beam and column cross-section. (3) Shear failure of the beam and column member. (4) Shear failure of the beams and columns connection. (5) Reduction of the flexural strength by the bars setted through the beams and columns connection. (6) Anchcorage failure of the bend bars. (7) Bond failure at the beam and column member. In the previous papers (Part I, Part II), the upper limitation of the steel strength can be utilized in the reinforced concrete beams, was analyzed by the upper conditions (1), (2), (3), (4). In this paper, it was proved that the steel strength could be utilized effectively in the reinforced concrete column, was limited by the upper conditions (2), (3), and, the upper limitation was analyzed by the condition (2), (3).
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TOSHIRO SUZUKI, KENICHIRO TAMAMATSU, ISAO KUBODERA
Article type: Article
1978 Volume 265 Pages
33-43
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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The experimental study was made on the three dimensional elasto-plastic behavior of space frames consisted of two rigid frames in one direction and two tensile braced frames in the other direction which are general structural system of low steel structures. Test specimens were one story-one bay space frames constructed with four columns and four beams of H-shaped members and with four tensile braces of round steels, and were tested under horizontally loading combined with axial load. From these experimental results, the following difference of the elasto-plastic behavior of space frames from plane frames were clarified. 1. Additional axial force in columns caused by deformation of braced frames makes the difference to the restoring forces of two parallel rigid frames, and torsion of frame is accumulated with repetition of loading cycles. 2. The maximum restoring force and plastic deformation capacity in direction of strong axis of H-shaped columns decrease under the influence of the deformation of columns in direction of weak axis.
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KUNIAKI UDAGAWA, KOICHI TAKANASHI, HISASHI TANAKA
Article type: Article
1978 Volume 265 Pages
45-52
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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In the preceding report, Part I, the following discussion was stated : When H-shaped steel beams are subjected to cyclic and reversed loadings with constant deflection amplitudes, load deflection hysteresis loops are stable within a certain critical deflection amplidute, while they become unstable beyond that deflection. However, the stationary hysteresis loops are again obtained, if the deflection amplitudes are reduced to within the critical one, even after the beams are damaged to deteriorate the strength. If the strength deterioration of the beams subjected to random deflections can be predicted from the results of the constant deflection amplitude tests, it is thought to be one of clues to prediction for failure of beams during an earthquake. Accordingly, in this paper how the strength of beams deteriorates due to various ratios of deflection amplitudes in the unstable deflection amplitude region is examined, and, based on those data, how to evaluate the strength deterioration of the beams subjected to random deflections is shown.
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TAKESHI UCHIYAMA, YOSHIZO DOBASHI
Article type: Article
1978 Volume 265 Pages
53-61
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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The design methods of the reinforced concrete staircase composed of either a system of folded plates or a helicoidal shell have been debated in terms of elastic beam theories, exclusive of very few instances of more rational approaches form elastic, elasto-plastic, vibrationary or other theories of plates and shells. To come before discussion of the entitled design procedure in the existing variform cases of both structural types, the report develops such a method of analysis of elasto-plastic behaviors of the relevant R.C. structures as finite element method using laminated elements, for the purpose of finding general design priciples by comparing the analytical with the available experimental results.
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TOSHIO MOCHIZUKI, HIROSHI KITAGAWA, TOSHIKAZU KOIZUMI, FUMIO NAGASHIMA
Article type: Article
1978 Volume 265 Pages
63-70
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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A new theoretical technique has been presented for the assesment of earthquake response of general yielding structure in previous papers (Part 1〜Part 4). In this paper, the applicability of this theoretical method is verified with on-line real time dynamic test for the pile-ground system. A test apparatus-computer on-line real time system has been developed for the purpose of estimating the vibrational response of structure consisted of members which have nonlinear force-deflecion relation accurately. That is, the tests on restoring force characteristics of members are incorporated into the loops of response analysis executing step by step with digital computer. In above the mentioned two kind of methods, a pile-ground system is converted into the single-degree-of-freedom system excited by accelerations which are sine waves, White noise. El Centro (1940, N-S), Taft (1952, E-W) and Tokyo 101. From the results of the analysis and on-line tests, the average ratio of discreparce is about 10% in the maximum response of acceleration, velocity and displacement between the two methods. It is concluded that the theoretical technique is sufficiently adapted for a dynamic hysteretic properties of structure.
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Shinji Ishimaru
Article type: Article
1978 Volume 265 Pages
71-80
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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TETSUO KUBO
Article type: Article
1978 Volume 265 Pages
81-91
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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For certain important structural systems such as nuclear reactor facilities, dynamic response analysis would be required in the future considering multi-component effects of ground motion input. In a case of simulation of three-dimensional ground motions by use of stochastic processes, a question immediately arises "Should the components of motion be cross correlated in a statistical sense?". If correlated, in addition to properties which establish the respective components, one must specify cross-correlations for the components. An orthogonal set of principal axes is defined for three-dimensional ground motion processes. These principal axes are determined to have maximum, minimum and intermediate values of variance and have zero values of covariance. This property reveals that the corresponding components of motion along the principal axes are fully uncorrelated with one another. Since real earthquake accelerograms are well represented by Gaussian random processes, the three components of motion along a set of the principal axes are statistically independent of one another. Using the concept of principal axes and applying a moving-window technique to the accelerograms recorded during the San Fernando earthquake of February 9, 1971, time-dependent characteristics of three-dimensional ground motion along a set of principal axes are determined. Results of the analysis indicate a significant correlation between horizontal directions of the major and intermediate principal axes and directions from the recording stations to the fault slip zone. In view of the existance of principal axes, it is concluded that the three components of motion can be generated in a stochastic manner being independent of one another, provided that a set of axes along which they are directed is treated as a set of principal axes.
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TOSHIO OJIMA, MASAKAZU MORIYAMA
Article type: Article
1978 Volume 265 Pages
93-103
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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In Part 1, it was observed by field survey in summer that the surface temperatures of various land uses were very different. In this paper, the first, the calculation method of the heat budget about 10 land uses of architectural scale (We called these land uses "10m LUN" i.e. 10m land use number) is described. "10m LUN" are (0) water surface, (1) naked ground, (2) paddy field, (3) grass, (4) shrub, (5) forest, (6) asphalt pavement, (7) Kawara roof, (8) zinc roof, (9) RC roof. Especially important factors about the heat budget are (1) earth surface albedo; p, (2) convective heat transfer coefficient; α_c, (3) mass transfer coefficient; k_q, (4) evaporative ratio; f, (5) thermal characteristics of materials-specific heat; C_p, specific weight; γ, thermal conductivity; λ. The values of these factors were assumed for annual calculation. The second, the results of the observations at the green area (Nagai Park in Osaka city) and various land uses (Tokyo area) were compared with the result of the calculation. From an analysis of the observation in Nagai Park (1974.8.5-8.8), the values of the calculated surface temperature coincided with the values of the observation, as a result of a combination of α_c and f. It was presumed that α_c : Slatyer and MacIlroy's equation and f=0.7. The result was comparatively rational. In an analysis of the observation in Tokyo area (1973.9.2-9.3), the calculation of the heat budget was done about various land uses. Although the surface temperature of the observation varied widely, but its values coincided comparatively with the values of the calculation. But the calculated surface temperature of natural earth surface (10m LUN (1)-(5)) vary widely with the assumption of the evaporative ratio f. The rational assumption about it remains to be proved.
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MASAMICHI ENAI, NOBORU ARATANI
Article type: Article
1978 Volume 265 Pages
105-113
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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In this report, the authors obtained the mean temperature at the ceiling θ^^-_sc and of the floor level θ^^-_sf during the hours of heating and mean outdoor temperature θ^^-_o in a day, and calculated θ^^-_is=(θ^^-_sc+θ^^-_sf)/2 as the controlled room air temperature and k=(θ^^-_sc-θ^^-_sf)/(θ^^-_is-θ^^-_o) as the ratio expressing the standard of thermal conditions. Generally as the more the thickness of insulation gets, and the smaller the temperature difference of θ^^-_sc and θ^^-_sf becomes, the ratio k gets smaller. In the early season of heating θ^^-_is in sufficiently insulated houses is controlled low than that in insufficiently insulated houses. And in the case of the convectional heating system, θ^^-_is increases according to the falling of θ^^-_o. On the contrary in the case of the partially and intermittently heated houses by using a stove (semi-radiation type), θ^^-_is decreases according to the falling of θ^^-_o, and in such houses the larger the ratio k becomes, the lower θ^^-_is is controlled. The reason is supposed as follows. In the insufficiently insulated houses, more heat supply will be required in accordance with the falling of θ^^-_o and the radiation from a stove will become stronger to the living space and it will warm human body directly, and thus the controlled room air temperature θ^^-_is will be lower. In this state, if the whole house will be heated by using a stove, the coldness of the floor level and the strong radiation around the stove will spoil the thermal living condition because of the cold air circulation from the adjoining rooms and the stronger radiation by trying to heat more. As the partial heating shall be necessarily done in such insufficiently insulated houses, the intermittent heating shall be inevitably kept because the warmth around a stove will not be necessary at night when there is no one there.
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TOSHIO OJIMA, TATSUO OKA, HIDETAKA KOMIYA
Article type: Article
1978 Volume 265 Pages
115-124
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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A heat product device as an urban model which was 3m×3m and was controlled by electrical heater from 2 to 5kw/m^2, was placed in natural wind field to investigate the temperature distributions using 76 thermocouples above the model. Wind profiles and eddy diffusivities were also observed. Summary of results obtained may be as follows. 1. H_m which is the quantity of heat in a certain volume of air above the model and indicates the intensity of the temperature distribution, is proportional to the surface temperature on the model when wind velocity is fixed, and inverse proportional to wind velocity. 2. Observed eddy diffusivities in horizontal direction (D_m) and in vertical direction (D_z) are expressed as, D_m∝V_m・z D_z∝V_m・z^n wher z is height from ground surface, V_m is wind velocity and n is a parameter which is 1.0 when V_m is larger than 1.2m/s and decreases with decrease of wind velocity when V_m is smaller than 1.2m/s. 3. Measured temperature was compared with calculated temperature by a numerical method using the relations above as conditions. Calculated results were well in agreement with experiment results in comparisons of these isotherms, where the correlation coefficients between these results were from 0.88 to 0.98.
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MITSUHIRO UDAGAWA, KEN-ICHI KIMURA
Article type: Article
1978 Volume 265 Pages
125-132
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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The practical procedure for the calculation of room temperatures and heat extraction rates for a multi-room building is described. The concept of multi-room in which the temperature of the adjacent rooms does not have to be assumed is important for the simulation of the room temperature or the heat extraction rate in the buildings such as residential housing with a mixture of intermittently conditioned and unconditioned rooms. The procedure for simulating the room temperature or heat extraction rate using time series concept with weighting factor method is useful for a single room, but cannot easily be used for multi-room calculation. Although the iterative methods for multi-room calculation based on the heat gain calculated for each single room to simulate the room temperature of the unconditioned rooms have been presented by Ochifuji and Takeda, iteration should require a large amount of computer time and might not be suitable for practical use. With the algorithms described in this paper, the heat extraction rate in conditioned rooms and the temperature in unconditioned rooms can be obtained by solving a set of simultaneous equations with a dimension of total number of the rooms. The simultaneous equations are composed of the heat balance equations among the rooms in which the heat conduction equations within all of the room enclosure components such as walls, and partitions are conceived and all the room surface temperatures are eliminated. In this method iteration is unnecessory. As the implicit finite difference method is used, this method allows for changing the time increment and the thermal properties of room enclosure components in the course of executing calculation. For example, it is possible to make calculations in such a case that drapes are drawn down during the night. Example calculations were made for a well insulated town house with 6 rooms and the effect of the insulated rain proof door was examined using the weather data of Tokyo in winter. The results showed that heating was not required in the south facing rooms on sunny winter days even in the night and in 20℃ could be maintained with a heating rate of 500 kcal/h in the north rooms with uninsulated double windows. It was found that the insulated rain proof door made the daily heating load less by 40% and the mean room temperature higher by 0.5〜1.5℃.
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SADAAKI OGISO, KENGO MATUMOTO
Article type: Article
1978 Volume 265 Pages
133-141
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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1. Effect of the Slenderness of Buildings The error due to the approximate calculation was examined in the last reports (1971.4). The factor of correction for that error was also indicated as the Table 2 in that report. But that Table was not arranged for the practical use. In this report, that Table was arranged as "the factor of correction due to the slenderness of buildings". 2. Result from the Drawing Experiments 3. Correction to the Direct Result by the Independent Assumption in the Theory of Probability 4. Analysis of the Effect of the Style of Building Distribution 5. Conclusive Indication of the Factor of Correction
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RINTARO KAWAMICHI
Article type: Article
1978 Volume 265 Pages
143-152
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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The present study is intended to explore two points as follows. (1) Is there such tendency as interpersonal relationships actually suffer a change by the increase of density in daily-life settings? (2) Is there any consistency with the tendency regardless of the disparity of spatial conditions? Analyses and examinations are performed separately into two kinds of residential areas; one is naturally built-up areas and the other is planned estates. In the naturally built-up areas some tendencies are found according to the increase of the density. They are a decrease of the number of friends and an inclination toward both extremities in the types of the geographical distribution of friends, and a decrease of the amount of hours spent for outdoor plays. These tendencies can be said as a whole "a tendency to shrinkage on the friend-formation". However, their tendencies cannot be recognized as a response of the effects of density per se, because they are not found consistently through two kinds of residential areas. In case of the planned estates, the effects of spatial conditions on the friend-formation is rather clear. It is considered as a whole the negative effects of the high density act on the human interpersonal relationships correspondingly with the condition of spatial settings.
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KIMIO TAKANO
Article type: Article
1978 Volume 265 Pages
153-162
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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To imagine a situation is considered to be the general method in planning and design. For example, in architectural planning, the existance of a model has much effect on imagining a situation. Nevertheless in the field concerned with an earthquake, excessive insufficiency of models it difficult to imagine the condition under an earthquake. The purpose of this study is to analyze the background for which to imagine situation is necessary, to present the story simulation, the method to imagine a situation systematically and to report the conception of the simulation model.
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TETSUO TAMAI
Article type: Article
1978 Volume 265 Pages
163-172
Published: March 30, 1978
Released on J-STAGE: August 22, 2017
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