This paper describes the air entraining performance of polycarboxylate type water reducer. From the results obtained in this study, it is concluded that Methoxypoly (n=10) ethyleneglycol methacrylate - methacrylic acid copolymer (PC-10) can be purified by utilizing its cloud point; The purified polymer obtained from PC-10 through using its cloud point shows the lower air entraining performance than that of PC-10, and the ingredient that displays the strongest air entraining effect for PC-10 is methoxypoly (n=10) ethylene glycol, which remains in PC-10 as a raw material or an elimination product generated by an alkaline hydrolysis of PC-10 in the cement-water system; In order to decrease the air entraining performance of PC, the side chains of it should be sufficiently hydrophilic: we reached the preliminary conclusion that as the end group of side chains, -H or -CH₃ group should be required and the side chains' length should be more than 30 moles in the additional number of ethylene oxide when the end group is -CH₃ group.

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The diffusivity of CO₂ in the gas phase of concrete pores is an important factor in the prediction of carbonation progress of concrete. In this study, the distribution of gas diffusivity from already carbonated surface zone to non-carbonated center zone in specimens, which are accelerated carbonation (in a controlled at 20 °C, 60 % R.H. and 5% CO₂) with several mix proportions were examined. Quantity open porosity, Ca(OH)₂ and CaCO₃ in specimens were also determined. As a result of this experiment, the diffusion coefficients in specimen from full carbonated surface zone to partially carbonated zone which is reacting with cement hydration by diffused CO₂ were not constant. It is indicated that the prediction of carbonation progress of concrete take account of this result.

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JIS A 1108 (Method of test for compressive strength of concrete) was changed in 1999, allowing a much wider range of loading speeds to be used. Since there is a possibility that the wider range of loading speeds would cause the test results to be scattered compressive strengths of concrete at arbitrary loading speeds were examined. The results are as follows. 1) The value of compressive strength at the maximum loading speed (1.0N/mm²/sec.) were higher by 3 % or less compared with those at the basic loading speed (0.6N/mm²/sec.). At the result at minimum loading speed (0.2N/mm²/sec.), the value of strength were lower by 5 % or less compared with those at the basic loading speed. 2) The influence of loading speed within the range of JIS A1108 on the values of modulus of elasticity and Poisson's ratio is small. 3) The transverse strain of the specimen increases at an early stage when the loading speed is slow.

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Energy consumption and CO₂ emission due to construction of buildings in China and Japan are described in this report. As more than 400 industrial sectors are contained in Japanese IO table and 30 sectors in Chinese IO tables, energy consumption and CO₂ intensities of dominant materials used in building are derived from energy consumption in factories and equipments are derived from IO analysis. Energy and CO₂ intensities of main materials used in building construction in China and Japan and the calculation methods are shown in this report. Office buildings in both countries are calculated as a case study. The intensities of materials in China are 2-3 times larger than Japan and energy consumption and CO₂ emission due to construction of office building in China is 10-20% larger than in Japan. Though energy consumption of structure in China is 2-3 times larger than in Japan, interior finish works and equipments for air conditioning etc. are smaller. Energy consumption due to Chinese office building construction are almost same as Japanese.

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In order to validate the LES(large eddy simulation) model for strong wind in actual urban area, this research performs the direct comparison between wind data estimated by LES and full-scale measurement data. Generally, LES cannot evaluate the absolute wind velocity, but can only a relative value to the reference wind velocity. In order to introduce the absolute value, we employ the meteorological model(MM5). In this study, first, based on the observation data on the rooftop of the high-rise buildings and several surrounding ground-level points, we clarify the flow characteristics of strong winds during cyclogenesis. Second, we numerically simulated the mean wind speed and the maximum instantaneous wind speed and validated the LES method through the comparison with the observation data. Accordingly the applicability of the present LES model for an actual shape of urban area has been clarified.

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Seismic response of one-story structure with the significant stiffness eccentricity, developing a torsional mode, is studied in this paper. Viscous damping is added to reduce both the translational and torsional vibration of the structure. The structure in such a case possesses the so-called non-proportional damping, which makes the conventional modal analysis using undamped vibration mode more inaccurate. On the other hand, more accurate method using the complex-valued mode is not easy for practical analysis, and is not very effective to understand dynamic response characteristies of the structure. Hence, this paper proposes a new modal analysis which uses the real-valued mode and yet treats the non-proportional damping effect with a unique correction process. Many cases of non-proportional damping are examined, and the reasonable accuracy of the proposed method is demonstrated through comparison with the other existing methods.

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Sloshing of a floating roof in an open-topped cylindrical liquid storage tank under wind loads is investigated analytically. Wind tunnel test in a turbulent boundary layer is carried out to measure the wind pressure distributing over the roof surface. The measured data for the wind pressure is utilized to predict the wind-induced dynamic response of the floating roof, which is idealized herein as an isotropic elastic plate of uniform stiffness and mass. The dynamic interaction between the liquid and the floating roof is taken into account exactly within the framework of linear potential theory. Numerical results are presented which illustrate the significant effect of wind loads on the sloshing response of the floating roof.

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In this paper, the influences of the phase characteristic and the response spectrum characteristic of the earthquake wave on the earthquake input energy are examined based on the earthquake response analysis using the simulated seismic wave which is adjusted the normalized response spectrum. As a result, the characteristic of ƒ value proposed by Akiyama and Kitamura is clarified, and proposes the response spectrum effect value S_M and ƒ^* value considering S_M value. The earthquake input energy of any earthquake wave without the case that earthquake response analysis is able to estimate using ƒ^* value. Moreover in this paper, ƒ^* value corresponding to the earthquake load which Japanese Building Standard Act provide is presumed by conducting seismic response analysis of real buildings. Therefore, on the comparing with ƒ^* values of the existing seismic waves, the quantitative evaluation about that earthquake damage can be performed. The evaluation of the earthquake input energy based on ƒ^* value as well as acceleration at the maximum is necessary for the evaluation of the earthquake wave. The ƒ^* values are useful on the evaluation of the input earthquake wave.

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We hypothesized that the scale of the predicted Nankai Earthquake will increase gradually year by year as the time passes from the last occurrence in December 1946, and then we estimated strong motions chronologically from 2009 to 2060 for western Japan based on the up-to-date strong motion prediction method, i.e., the so-called statistical Green's function method with hierarchical source heterogeneities. Next, we input the derived chronological strong motions into a set of nonlinear response analysis models proposed by Nagato and Kawase and estimated building damage ratios for different structure types and numbers of floors. When we compare the evolutional damage ratios of buildings in the subject regions with those for the reference case (corresponding to the scenario that will happen in 2036), we found that for every 10 years of delay in occurrence of the mega-thrust Nankai event we must expect 40% of increase in building damage, mainly in the epicentral areas.

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To control base displacement in seismic isolation structures subjected to large input level earthquake, variable oil damper (VOD) has been proposed and developed. Damping force of the VOD is changed automatically by internal mechanism without computer and power supply, when base displacement becomes large. In this study, the mechanical properties of the VOD and its application for seismic isolation structures are investigated. Results of experimental and analytical studies shows that the response displacement of isolated story is decreased, while response acceleration and story drift of superstructure are slightly increased by the VOD effect.

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Authors have proposed an analytical method for H-shaped steel beam-column involving local buckling behavior. And we have studied methods to analyze the elastoplastic buckling behavior of truss members. In this paper, we will extend both methods for H-shaped steel truss member. Then, we will propose a consistent and convenient truss element for H-shaped steel member involving overall and local buckling behavior. This truss element is formulated based on thermodynamics. In formulating, the yield function and the evolution equation considering local buckling are confirmed by analytical results of discrete model. And the softening property caused by local buckling is given from study on plate buckling behavior. Finally we will examine the validity and usefulness of our method through some numerical examples.

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The purpose of this paper is to propose a rational inverse problem approach to the seismic retrofitting of an existing building connected with an adjacent newly-built outer frame by viscous dampers. The mass and stiffness of the existing building together with the mass of the outer frame are given. Then the stiffness of the outer frame and the damping coefficient of the connecting dampers are found so that the requirements on the maximum interstory drift of the existing building and on the retrofitting possibility by the outer frame are satisfied. By introducing an approximate but effective relation of an overall damping ratio h⁽¹⁾ with a connecting-damper damping ratio h^R of the rigidly supported model, a repetitive procedure required in the previous paper has been removed. It is concluded that the proposed approach is an effective method for designing the outer frame and the connecting dampers.

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It is recently more important to grasp the collapse behavior of structure, to make a better structural design. Though large span structures like dome are designed so that these members retain elastic properties for Level 2 earthquake motions, it is so useful to predict the collapse behavior against unknown large earthquakes. However, the roof structure of large span structures consisted of truss beams has so many members, therefore it is not realistic for structural designers to analyze with the full discrete model which can express in-plane and out-of-plane post-buckling behavior of truss chord members. Therefore, the simple and systematical analytical tool which can evaluate these collapse behavior of truss chord members is needed. In this study, we consider the section of the truss beams separated by lateral stiffening members as one element section and propose a convenient beam element which can evaluate the lateral post-buckling behavior of truss beams.

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The theoretical predictions brought into discussion by author's previous papers motivated us to carry out a series of experimental studies on the load-displacement behavior of laminated rubber bearings in an excessively large deformation. One of the key issues intrigued us is that the slenderness of the specimen plays an important role to stabilize the buckling behavior even under extreme circumstances of large deformation. Another issue also interesting and important is the shear stiffness associated with the rubber has a vital effect on the stability of the bearings in a large deformed shape. The result of the experiments strongly supports the theoretical predictions and it unveiled the superbly stable load supporting capacity latent in the laminated rubber bearings with rather slender configuration.

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Shape optimization of shell roofs subjected to strong wind is carried out to minimize the maximum vertical displacement. The three dimensional (3D) fluid flow analysis is performed to obtain highly precise dynamic wind load. To reduce the large computational cost of the 3D analysis, the multigrid method is employed to solve the pressure Poisson equation. The objective function of the optimization problem is expected to have strong nonlinearity. Employing Response Surface Model (RSM), the objective function is approximated as a smooth function so that computational cost of the optimization is reduced. Analyses for several experimental points are required to generate RSM. It is not practical to perform 3D analyses for all experimental points due to huge computational cost. Variable Complexity Model (VCM) is useful for generating RSM. VCM is the method combining a high-fidelity model and a low-fidelity model. As the method of generating RSM, two kinds of methods are employed ; (1) VCM (2) 3D analyses for all the experimental points. Optimized shapes are obtained by both methods. Although the value of the objective function of (1) is slightly larger than that of (2), the computation for (1) is much faster than that for (2).

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The present paper proposes an efficient method for evaluating the elasto-plastic buckling loads of two-way single layer lattice domes under vertical loads. The connections are assumed semi-rigid as formed with screwed bolt-to-ball joints. The procedure of the method is composed of the following steps: linear buckling analysis to find the generalized slenderness ratio of the specific member that is the most relevant to their loading capacities; the generalized slenderness ratio is applied to obtain the axial strength for the specific member, based on which the elasto-plastic buckling load is evaluated. The comparison of the evaluated buckling loads with those obtained from FEM elasto-plastic buckling analyses proves that the procedure is valid and efficient enough to be applied in design practice. Based on safety factors, given in some recommendations, the allowable column strength is also proposed for proportioning the members of the single layer lattice domes.

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It is important that dynamic performance of bearing walls is elucidated for aseismic capacity of timber structures. Therefore resistance of bearing walls becomes important. I report this article about Influence of loading by constant speed on shear properties of nailed wooden bearing walls. And I paid my attention to resistance of bearing walls and based on experimental result I evaluated three phenomena.

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This paper describes seismic behavior of three different wood construction, timber frame with moment resisting joints, conventional wood house with shear wall and composite structure consisting moment frame with resisting joint and shear wall on the same floor.. Some performance evaluation procedure such as allowable stress design, horizontal load-carrying capacity method using pushover analysis and so on. The shaking table test was conducted to evaluate the capability of seismic design method. The non-linear skeleton curve is good agreement between analysis and test result in timber frame with moment resisting joint and composite structure but ii is a key point to determine the limit deformation of column and joint in bending. In conventional construction, the skeleton curve calculated from cumulation of shear wall including non-structural wall in structural design is 10 to 20% lower than that of test result as well as the past similar study.

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The mud-plastered wall has come to be regarded as an important earthquake resisting element for Japanese traditional houses through recent researches. However, because its materials, which are completely natural resources, are gathered around the constructing place and every district in Japan has its own constructing method, shear loading tests of mud-plastered walls are needed to clarify the shear resisting performance of a mud-plastered wall in every district. In this study, to evaluate the shear resisting performance of every mud-plastered wall in Japan at lower cost, the numerical analysis model of mud-plastered walls by means of Rigid bodies-spring model (RBSM) are discussed. Moreover, the validity of the former proposed shear resisting mechanisms to estimate the shear strength for mud-plastered walls are discussed from the analysis results.

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Experimental investigations on retrofitting soft-first-story RC frames by thick hybrid wall technique as a strengthening-ductile method are briefly explained. The mathematical models and hysteretic behaviors of the members retrofitted by thick hybrid wall technique were assessed and calibrated through the experimentally observed mechanisms. An existing soft-first-story RC building was selected to evaluate the efficiency of thick hybrid wall method on improving seismic performance of the building during strong earthquake excitations. The building was assumed to be retrofitted by two types of retrofitting methods including installation of shear wall (strengthening type) and application of thick hybrid wall (strengthening-ductile type). The evaluations were implemented approximately by seismic vulnerability assessment based on the guidelines by Japan Building Disaster Prevention Association and exactly by nonlinear dynamic response analysis. The analytical results showed the retrofitted building obtained reasonable performance for design basis earthquake at life safety limit state. Moreover, as a case study, the collapse prevention performance of the building retrofitted by thick hybrid wall was checked under an upper-bound of earthquake excitations based on recorded strong earthquakes (which herein are called maximum capable earthquake), and the obtained results demonstrated an acceptable performance.

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This research deals with a seismic retrofitting technique of installing CES portal frames to an existing RC frame building. One of characteristics in the retrofitting technique is to employ the precast construction method that precast CES members are connected at the middle of the beam and columns of the portal frame. This retrofitting technique also uses both the adhesive joint method and the post-installed anchoring method to unify the existing RC frame and the installed CES frame. Static loading tests were conducted for a total of four one-bay one-story frames including one bare frame and three retrofitted frames with the experimental parameter of connection details between the existing RC frame and the installed CES frame. Dynamic loading test was also carried out to compare the dynamic behavior with the static behavior of the retrofitted frames. This paper outlines the testing and presents the effect of the installed CES portal frame on the seismic performance of the retrofitted RC frame.

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Semirigid connections of beam-column using high tension bolts and angles were tested under a constant axial force and a repeated horizontal force, and the hysteretic behaviour of the connection is investigated. The restoring force characteristics of the connection is also formulated and the is compared with test results. Test results show that hysteretic behaviour of the connections of beam-column is considerably stable in the large range of deformation, and is traced well by the proposed formulae.

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This paper presents results of full-scale tests conducted to evaluate deformation capacity, failure mode and possible effective retrofit of welded beam-to-column connection adopted in moment frames for early high-rise buildings around 1970s. Test specimens are designed and fabricated to retrofit the moment connections in the 1970s by strengthening of the web connections and improvement of welding detail according to the latest practice. Loading tests are conducted by the cyclic loading protocol to simulate the response of frames subjected to long-period ground motions. The test results are compared with the results on original connections and the effectiveness of the strengthened web-joints on deformation capacity is revealed. The obtained capacity of specimens satisfied deformation demand predicted by numerical response analysis.

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Eccentric beam-to-square tubular column connections in steel building frames have been investigated by many researchers. For eccentric beam-to-wide flange column connections, fewer efforts have been made in the past. In a recent study by the authors, local strength of the eccentric beam flange-to-wide flange column connections was examined. This paper presents strength evaluation of panel zones in the eccentric beam-to-wide flange column connections. A torsional moment induced by an eccentric beam-flange force is considered in the derivation of the panel zone strength formula. Cyclic loading tests of T-shaped connection models have been conducted to examine the hysteretic characteristics. The test results show that the eccentric connections have adequate ductility and hysteretic energy dissipation capacity. The strength formula of the panel zones has a reasonable accuracy. Elastic-plastic finite element analyses performed for the cruciform connection models demonstrate influence of the stiffener sizes on the panel zone strength.

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For the purpose of making clear the effect of fracture at the end of the girder after earthquake upon ultimate temperature this paper has studied analytically the ultimate temperature of earthquake-resistant steel frame after earthquake. Assuming that steel frame consisting of 3 stories and 1 span undergoes fracture at the end of the girder by earthquake and it is subsequently subjected to fire at the first story refined finite element analyses as well as a simplified theoretical analysis have been conducted at earthquake and at fire. It is found that, in case that residual slope by relative story displacement does not exist their ultimate temperature is less decreased compared with those of frames without fracture at the end of the girder, but in case that residual slope by relative story displacement exists their ultimate temperature is decreased with increase in residual slope by relative story displacement or effective slenderness ratio compared with those of frames without fracture at the end of the girder.

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In the present study, the authors reexamined experimental data on stress sharing of constituent elements of SRC interior beam-column joints to clarify the stress-transfer mechanism of SRC interior beam-column joints. The following conclusions were obtained. The shear strengths of transverse steel flanges depend on the distance and the beam column depth ratio of the transverse flanges. The shear strengths of RC differ in the confined effect on concrete by the differences in steel column cross-sectional shape. It was clarified that concrete stress in the ultimate shear strength of a SRC beam-column joint was transmitted by the strut on the diagonal line of the beam-column joint. A convenient method was proposed for obtaining the strut width. In addition, regarding the effective width of beam-column joints, each stress in the three zones where stress transmission seemed to differ was clarified; an equation of the effective width of beam-column joints was proposed. Adequate shear strength estimation for SRC beam-column joints was also proposed. As a result, the correspondence of calculated and experimental values was drastically improved.

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For-profit buildings in cities such as commercial buildings for rent play a significant role in urban economic activities, and their failure would cause enormous economic loss. To reduce such losses in the event of a severe earthquake, it is necessary to clarify the damage limits of for-profit buildings in terms of business continuity.
This paper investigates the seismic performance of for-profit buildings in terms of economics by introducing an economic damage indicator and discusses the following issues. (1)Permissible repair cost for buildings derived from property information such as construction cost, projected revenues and discount rate, and a resulting “damage limit” for failure in business continuity. (2)Upper-bound investment for earthquake resistance derived from a balance between cost for earthquake resistance and its benefit, and resulting “inevitable damage” in terms of economics. (3)Vulnerability of urban for-profit buildings with low business risk to earthquakes, compared with rural for-profit buildings with high business risk. (4)Significance of establishing a design procedure that considers the “damage limit” and “inevitable damage” in order to reduce economic losses caused by failure in business continuity of urban commercial buildings due to earthquakes.

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This paper proposes a new place-name classification table considering geographical features and soil characteristics, which helps interpretation of seismic hazard maps. This table is classified into two soil groups (stiff soil and soft soil) based on the origin of their Chinese characters. We select bus-stop name from many kinds of place-name. This reason is the following two points. Distribution density of bus-stop is almost evenly in the city, bus-stop name mostly remain past place-name. The validity of the new place-name classification table and bus-stop name is clarified through case studies on the three major metropolitan areas of Japan.

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