In this paper, we describe the study of the monitoring test using the full-size simulated models related to durability of coating and effect of surface coating of concrete for preventing penetration of the salts transported by sea breezes. First we study the effects of factors influencing durability against the concrete which coated and uncoated. Next, we have the result of the concrete properties, chloride contents and carbonated thickness. Finally we conduct the properties of concrete durability (chloride contents and carbonated thickness etc.) up to 20 years age and the method of monitoring test using the full-size members simulating general part of the real structures.
Applicability of high-strength/high fluidity concrete using eco cement to environment-conscious CFT was examined. As a result, the following conclusions were obtained. (1) The high-strength/high fluidity concrete can be made by using eco cement. (2) The amount of the chlorine ion of this concrete can be measured by the bleeding water gathered at 60 min. after mixing. (3) Core strength of high-strength/high-fluidity concrete using eco cement is almost the same as the case to use ordinary Portland cement. (4) Elastic modulus of concrete using eco cement can be estimated by the expression of JASS5.
The dry brick masonry method has been limited to a simple wall plan that is the straight line and rectangular, etc. In this study, the layout logic of a curved wall and a bay window wall for the dry brick masonry method was examined. And the construction experiment of a special formed wall was done, and the feasibility of a curved wall and a bay window wall was examined. The conclusions are as follows. The layout logic of a curved wall is that the bolt hole is allocated on the circular arc by 120mm pitch, the starting point and the terminal are on the grid center, circular arc length becomes the multiple of 120, and the number of bolt holes at intervals becomes an even number. It was able to be confirmed that a curved wall and a bay window wall of the dry brick masonry method were good at the masonry by the construction experiment.
The authors have been developing low-rise reinforced concrete masonry buildings with the wall thickness of 150mm, for the purpose of the increase of inner space of buildings, the decrease of building weight, and the usage of the standard building module of 300mm. In order to realize the buildings, compressive behaviors of fully grouted concrete masonry prisms, using newly developed small-size units with the strength of 40N/mm2 class and grout concrete of the strength of 40-60N/mm2, were investigated. Special pre-mixed cement mortal was used for the joints to obtain high out-of-plane bending performance.
The water-proof test method of placing joint and cracking parts of concrete under high water pressure is proposed for evaluating the under ground concrete structure. The shape and size of concrete specimen, the high water pressure test apparatus and the leading crack apparatus are developed. The effects of the period of placing joint, the type of water stop material, the kind of waterproofing membrane with cracking at its behind on the water proof performance ware tested under the high pressure. The test results are shown clearly differences in type of material and kind of construction specification. The proposed test method can evaluate the water proof performance of under ground concrete structure under high water pressure.
Many tower cranes were damaged by the Hyogo-ken Nanbu earthquake in 1995. There were two kinds of serious damage types. But the strength of those damaged tower cranes corresponded to the design code. The causes of these damages were examined by the numerical analysis simulation. The reason for the cause that damage grew up was that the seismic force amplified with the building was input to the tower crane. Therefore, the damage of tower cranes connected with the building was serious. However, the seismic performance of the tower cranes improves by the friction dampers installed in the stays.
As for historic structures, aged deterioration such as weathering is conspicuous on the surface of brick and stone structures. The purpose of this study is to devise a tester which can measure surface strength distribution of structures by slight-destructive inspection. As the first step, a tester has been devised experimentally, and the material and the form of the drill bit have been determined by the basic experiments. As a result, we found that the most suitable quality of the meterial for a bit tip was a diamond, and column type one was desirable judging from the stability of the drill speed. A surface strength test using this diamond bit on an actual terra cotta has demonstrated the possibility of definite evaluation of the relative strength and thickness of the glaze, and the relative strength of the foundation. Evaluation of the absolute strength of materials will be discussed in the following steps.
In recent years, external insulation building is chiefly constructured to the cold district. But it is easy to be deteriorated variously about siding materials. One of the main causes is thought that temperature change of siding materials by being exposed to the sun. State of dry and wet of siding materials changes by the season and weather is also the main cause. This research clarified that relation between wall composition and expansion and shrinkage of the siding materials in external insulation building.
Base isolated high-rise housing must offer safe and comfortable life not only for an earthquake but also for a storm. In order to raise base isolated effect for an earthquake, base isolated story should be made mobile for small power. On the other hand, once base isolated story moves by a storm, excessive displacement will remain, so a stopper is necessary against a storm. In design of base isolated high-rise building, we need to solve this contradiction. We developed a rational trigger system using a device “Shear-pin with a gap resisting wind load” which ensures base isolated performance and applied it to two projects.
There is a difference in the vibration characteristics between the real building and the analysis model used at the design stage. In this research, the micro-tremor measurement, the free vibration test by the human power and the seismic observation were carried out for the steel structure office building of 14 stories. These tests and observation results were examined from the small vibration level to the medium-earthquake response revel. And the validity of the dynamic analysis model used at the design stage was discussed.
The structural damages of buildings have gradually decreased in recent earthquake disasters. However, during strong earthquakes, human damages were caused by the overturning of furniture on the floor or the falling of the ceiling. We carried out questionnaire surveys to grasp consciousness of inhabitants and the actual circumstances of measures about the indoor damages. It is analyzed on the questionnaire results of the number more than 600 parts. The consciousness of inhabitants has examined for reduction of the human damages with the indoor damages. For disaster-prevention in strong earthquakes, it also summarized the present problems in measures about the indoor damages.
The broadband strong motions by large magnitude subducting earthquakes need to be estimated accurately to promote rational and effective earthquake resistant design of large structures or plans for counter measures of seismic disaster in urban area. We simulated the broadband strong motions in the Tokyo metropolitan area during the great 1923 Kanto earthquake by hybrid method. The distribution of seismic intensity calculated from the simulated strong motions fits the distribution of ratio of collapsed houses during the Kanto earthquake. From this result, the simulated broadband strong motion time histories can be applied to the earthquake resistant design of structures and the plans for counter measures of seismic disaster.
Thin layer method is numerically effective tool to evaluate theoretical ground motions due to large-scale seismic fault, especially when fault parmeters have large complexity or soil property gradually varies in depth direction. In spite of those advantages, there remain several problems in connection with its formulation, e.g., discretization artifacts, artifical reflection of waves impinging at the bottom, and numerical instability when epicentral distance is extremely small. This paper describes some modeling techniques to improve these numerical problems and shows its validation. This method is also applied to ground motion evaluation at near-fault, surface faulting and the 2007 Noto Hanto earthquake.
We have already proposed optimum response control method of the system using linear viscous element with inertial mass connected in series to a linear elastic bracing element. In this paper, we discuss the method of substituting equivalent nonlinear viscous element for linear viscous element in the optimum control system. The proposed method is validated through numerous time history analyses over a wide range of mass ratio (added mass/main mass), and phases and spectrum characteristics of earthquakes.
Not only the seismic retrofitting but also the prevention measures of the indoor furniture overturning are important for the human damage reduction at the earthquake. Then, the vibration test was done in this study with three kinds of furniture and 11 kinds of overturning prevention apparatuses. Effectiveness of the overturning prevention apparatus was brought at the strong motion together with the experiment in the past. Moreover, the experiment animation is disclosed on WEB, and a diversified evaluation like easiness to install and the economy, etc. is done.
The sloshing damping devices using floating net was developed for the damage measures of the oil storage tanks with floating roof by earthquake generated sloshing of liquid. In this paper, the shaking table tests with a scale-down model tank and the free vibration tests with a real model tank were executed and the effect of the floating net of sloshing wave height control was confirmed. Moreover, the presumption equation of the damping factor of the floating net was considered.
The effects of embedded fill and cut soil on the ground motions as well as on the response of structures supported on the sites were investigated by the micro tremor measurement. The main findings obtained through the study are as follows: 1) The predominant frequency measured on the embedded fill site is almost independent on the depth of the fill soil. The amplitudes of the ground motion tend to increase with increase of the depth. 2) The effects of soil on the structural response tend to be more pronounced for a structure supported on the embedded fill soil than the structure on the cut soil.
It is important to establish an accurate vulnerability function to estimate seismic damage. The purpose of this study is to expand vulnerability functions of wooden buildings using seismic diagnosis data based on equivalent linear models. The vulnerability functions consider characteristics of the region such as ground and building characteristics. The paper describes a method to calculate ratio of building damage in a region. The accuracy of the method is verified using the damage data of the Great Hanshin-Awaji Earthquake Disaster.
In case of the bearing capacity of a pile, tapered piles installed by the press-in method have more convenient points than straight-sided piles. Some sorts of in-situ tests, including press-in tests, axial compressive tests, uplift tests and lateral tests, were carried out on the steel pipe tapered piles in Kanto Loam. This paper presents the outline of the tests, the results of the tests and so on. Moreover, the discussions about the test results are presented.
Rotary penetration small size steel piles are used for foundation systems of light weight structures such as residential buildings. But, compared to construction cost, exact calculation of the bearing capacity of such footings mobilizing both soil and pile reactions is rather complex. A simple and rational design method for such footings is proposed and examined. In the method, the stiffness of soils and steel piles are separately evaluated based on Sweden Sounding Test, and then, the complex action mechanism of the foundation system including soil and pile reactions is studied. As a result, the evaluated stress in footing beams can be reduced to 50%, if the soil reaction is taken into account in addition to the pile reaction.
The dispersion in the characteristics of adjacent ground is examined based on the several cone penetration tests. It is shown that (1) N-values in the same stratum vary due to the small shift in the depth of the hard and soft points, and are in good agreement if the depth is corrected; (2) Althought the coefficient of variation from the all measured data is large, the mean value coefficient from certain range of depth is comparatively small; (3) It is conclude that the coefficient of variation used for a pile skin friction has to be selected based on the mean values within a certain range of depth.
In this paper, the modeling error for the NPP building fragility evaluation in the strong nonlinear area of the seismic response model is investigated. In the study, the restoring characteristic model of the RC bearing wall used for the response analysis of the lumped mass model was focused. 7 parts where the nonlinear level is expected to be strong during the strong earthquake in typical nuclear reactor buildings were extracted, then seismic response analysis using the model were conducted and the fragility curves were calculated. Comparing with the results of FEM model, the modeling error (β uN) was estimated about 0.1.
In disasters, spatial structures such as school gymnasium fill the role of the shelter. Seismic evaluation and seismic retrofit of gymnasiums and halls have been done. However, the scheme of seismic evaluation and retrofit of spatial structures have been done through the usage of those of frame buildings of normal scale almost without paying attention to demanded abilities of spatial structures. Besides, the phenomena peculiar to spatial structures such as vertical vibration and unevenness of deformation are not necessarily treated with sufficient considerations. Consequently, it is important to investigate the applicable range of the present seismic evaluation scheme of spatial structures. This paper principally aims at clarifying the applicability and problems of the present seismic evaluation of spatial structures. As the first stage for such purpose, elastic time history analysis has been carried out for existing school gymnasiums and their dynamic behavior is examined. From the comparison of these results with those obtained through the seismic evaluation scheme, some problems of the present evaluation are considered.
A new method has been proposed by authors to measure membrane stresses in two different directions separately, where instead of measuring the membrane stresses directly, the natural frequencies of the membrane within fixed rectangular region resonated by white noise external excitation with the frequency of 0 to 500Hz induced by sound is utilized. The new method makes use of the resonance phenomena of the membrane, where the effect of added mass of surrounding air was found not to be able to ignore for high accuracy measurement, and theoretically evaluated by using an equivalent circular plate. In this paper, not only the process of the equipment improvement toward high accuracy and the result of experimental test on every process to verify its accuracy, but also the experimental test of actual suspension membrane structure are presented.
Wind response characteristics of a five-storied pagoda were clarified in this study. The wind response analysis was carried out using wind forces obtained from wind tunnel tests with a scaled model of five-storied pagoda and an elasto-plastic structural model of the five-storied pagoda considered with non-linear structural system of traditional wooden members.
This paper deals with the experimental study of the eartuquake resisting wall using toughened glass. Load bearing tests were conducted to determine the ultimate horizontal strength and deformation capacity. The result shows the wall using toughened glass has enough strength as the earthquake resisting wall for wooden house.
Kenaf has less cellulose and lignin and more hemi-cellulose. Therefore, a board can be built only with a kenaf. Moreover, kenaf may contribute toward the reduction of green house gases. Nowadays, chemical sensitivity has been a problem with the volatile organic compound (VOC) emitted from building materials. This problem may be solved by using an inorganic compound for the adhesives of building materials. This research aims at development of kenaf board using the sodium silicate solution which is an inorganic compound as adhesives and examination of the bending strength of the proposed kenaf board. Consequently, it is clarified that the influence of the water content and the additional ratio of adhesives on the bending strength of the kenaf board.
For the purpose of evaluating the seismic performance of masugumi, which is one of the most important architectural components in ancient Japanese wooden buildings, the shaking table tests using a full-size masugumi component were carried out. From the comparison of shaking table tests with static lateral loading tests, which had been carried out before, it was found that the initial stiffness obtained from shaking table tests was in agreement with the one obtained from static loading tests. In this paper, the rotating angle and slip deformation of each element of masugumi are also discussed.
This paper describes the structural performance of tensile bolt with bond on wood post-beam construction. The structural key issue of the moment-resisting joint using this bolt is to evaluate the tensile strength of embedding bolt with bond. Tensile tests in the variant of the dimension, bond, shape of insert hole, embedded-dowel length and so on were carried out. To predict the strength of the bolt, the tests for sliced timber through bolt were also carried out. As the results of their tests and calculations, influencing factors of the bolt were defined and moment-resisting performance was predicted using result of tensile bolt test.
A passive control device with viscous energy absorber has been developed to mitigate the earthquakes damage to wooden houses. This paper describes the experimental results conducted for performance evaluation of houses with the control devices based on shaking-table-tests. Five framed specimens with and without the control device have been tested. It was shown that the maximum displacement of the structures with control device has decreased about as much as 1/3 to 1/2 comparing to the structure without the control device.
The authors of this paper have developed a earthquake force reduction system for the wooden houses. This contruction method involves the fixing of a friction damper in the form of a brace to the wooden frame using steel brackets and pipes for added damping effect. In order to confirm the damping properties of this earthquake force reduction system, static and dynamic shear force loading tests were conducted on a plane incorporating the friction damper. The results showed that the bracket and steel pipe were sufficiently rigid and flexible to fulfill the original damping effect of said friction damper and the loading deformation curve of the total plane clearly indicated sufficient damping properties.
This paper describes the results of investigations operated on four timber apartment houses and their seismic diagnosis. The results of the seismic diagnosis were far below the required values in the Building Standard Law. The authors conducted structural reinforcement repair work on two of these apartment houses in collaboration with the Foundation of Sumida Community Development Cooperation in Kyojima. Detailed investigation accompanied by partial destruction of the memgbers were conducted before the repair work, and deterioration of the hidden members were revealed. Their structural performance evaluation is discussed based on the results of the detailed investigation and repair work.
The authors have clarified the bucking strength of compressive plate section members with eccentric lateral support by theoretical and numerical analyses and loading tests in the previous papers, and suggested that the eccentric lateral support for plate-section column has equal effect to the support along the whole section. This paper discusses the buckling strength of the plate section members with eccentric lateral support under bending. The design method of such members relating bending and compression is suggested, followed by the applications to the plate section columns for actual buildings.
This paper presents research results on changes in material characteristics of the existing steel super-tall-chimney affected due to corrosion. The research was carried out on the strength, fatigue characteristics, residual stresses, macro-and micro-compositions, etc. of corroded sections. It is concluded that there is no adverse influence of corrosion on the material characteristics.
The experimental study on precast Concrete Encased Steel (CES) columns is outlined and the structural performance of the precast CES columns is discussed in this paper. The precast CES columns are constructed by connecting precast CES elements using bolts and fiber reinforced mortor. Fiver reinforced concrete is used for the precast CES elements. The purpose of this study is to obtain fundamental data on the structural performance and to construct analytical models of the precast CES columns applicable to pushover analysis used in the Calculation of Response and Limit Strength (CRLS). The results showed that the flexural strength of the precast CES columns is developed by the yielding of their steel and the lateral deformation capacity is about 0.05 rad. in the story drift angle. The shear versus lateral displacement response of the precast CES columns is simulated by the Takeda model.
Building constructions by dividing the members need structural designs considering construction processes. In this paper, the reasons for doing the designs are analyzed by structural analysis and arranged from the view-points of construction procedures, building shapes, building stiffnesses and modeling of construction conditions. And a structural design system considering construction processes for structural engineers is suggested. In the system, templates of construction processes separated from building information and searching construction procedures by genetic algorisms help structural engineers to consider construction processes.
In this paper, we experimented on a numerical experiment and a real large floor to show the vibration propagation characteristic of the dry double floorings which depended on the impulsive force. In the numerical experiment, it was confirmed that the eifference of the shape of the impulsive force was one of causes of the difference by nonlinear. In the real large floor experiment, it was different that the propagation characteristic measured by impulsive force characteristic (1) and (2) (JIS A 1418-2: 2000). The attenuation of the vibration of impulsive force characteristic (1) was small in 80-500Hz (1/3 Oct).
We conducted an examination of the dummy head with an impact force equivalent to the human head and conducted head impact tests using ordinary residential floors. We furthermore examined the effects of impact buffering by changing cross-sectional specifications of the direct-pasted wooden floorings. As a result, we got the followings: (1) The dummy head is probably a useful impact source equivalent to impacts to human heads, (2) Direct-pasted wooden floorings, by selecting the base material, impact buffering would have a considerable effect on fall impacts and it would also be possible to ensure proper elasticity while walking.
Presently long-span void slabs without beams have been used often because of less restriction for making plan. Because of having a long span, large slab makes low natural frequency compared to that with beam, they have a possibility of having a vibration problem. The purpose of these experiments is to establish the way of evaluation of floor vibration, of floor vibration experiment and of design on a aspect of floor vibration. In this paper, we report the result of the analysis of damping constant at a point of design, and explain the damping constant at the natural frequency and about frequency characteristics of damping constants.
This study shows the actual measurement and simulation results of heat flow through a solid floor in contact with the ground and with a vertical layer of edge insulation. The rate of heat flow was estimated to be about 3-5 W/m2 in summer, which was about twice as large as one by a wooden floor. The results also show that the improvement of insulation over the current is not always effective except the outside insulation of the foundation. The use of an overall layer of insulation under the concrete must be studied by the thermal property of the ground under the floor.
The greenhouse cultivation is often used by the agriculture. It is possible to grow vegetables in the greenhouse in summer if the greenhouse is airconditioned. In addition, the amount of agrichemicals decreases, because the insects do not enter the air-conditioned closed greenhouse. However, there are few air-conditioned greenhouses. It is uncertain whether the air-conditioned thermal environment is appropriate to cultivation. Authors measured thermal environment of the greenhouse and electric consumption of air-conditioning in summer, and showed the result of the cooling load and electric consumption calculated with TRNSYS.
The purpose of this research is in creation of “the aesthetic check list” as a design code in case designers are going to create beautiful space. People's aesthetic value was extracted using the Evaluation Grid Method as the method. Next, relation with this aesthetic value, age and sex, besides educational environment was considered. The aesthetic value extracted by the Evaluation Grid Method was made into the keyword of “the aesthetic check list.” And we added a footnote and devised it so that it is a more concrete check list. “The aesthetic check list” is utilized by many people, and we hope that much beautiful air space is created.
In this paper, measurements and visualization of natural ventilation were performed in the building with a monitor roof in order to examine the effect on the indoor thermal environment and the ventilation property. As a result, it was suggested that a monitor roof was effective to improve the indoor thermal environment because it caused vertical ventilation driven by the difference of temperature between indoor and outdoor or between above and below and it brought increase of discharge rate and drop of indoor.
A sustainable college building with 2 solar chimneys was completed in the Spring of 2004. Since then, authors have continued to measure natural ventilation rate using SF6 and C2H4 as tracer gases to know those of class rooms and whole building. At the same time, thermal conditions, air flow directions and pressure differences were also measured. Based on these data, multi rooms ventilation calculation models were developed, by which effects of some improvements for chimney systems were examined. At the next step, the authors have developed heat balance simulation model around chimney, which showed good accordance with measured values and adequate heat capacities of construction materials were studied to get constant ventilation rate through a day.
This study intends to grasp the consumption of cold and hot water and gas, which are wasted in a short time when cooking and washing-up using a single-lever kitchen faucet, and ultimately aims to examine the effectiveness of single-lever faucets which are initially developed to reduce such wasteful consumption. The first report concentrates on experimentation on washing-up activities using volunteers and the results of the basic experimentation are reported providing a fair idea of how often activities are performed as well as enabling the understanding of short-time usage of cold and hot water and gas, which possibly leads to wasteful consumption.
In 2006, the local government of Shinagawa Ward located in the central Tokyo and we have developed the microclimate measurement network which is called Shinamoni as a new tool for Eco-Conscious Urban planning. This system is design to verify countermeasures of the heat island phenomenon, and to raise awareness of urban environment by providing real-time data on the website. The data is also used for prevention of heat attack and environmental education at elementary schools. In this paper, we introduce the operational situation and the utilization of this system.
The purpose of this study is to be easy for calculating the CO2 emission associate with building construction. In this study, the CO2 intensity is derived from four sector classifications of input output table on 2000. And the CO2 intensity is derived from new sector classification too. A case study on the CO2 emission associate building construction is made from the CO2 intensities that is derived from five sector classifications.
This paper reports the results of a field survey on the indoor thermal environment in two terraced houses in Johor Bahru city, Malaysia. The survey was carried out in a single-story house and a two-story house. The results show that opening windows not only affects ventilation but also controls the influence of the outside thermal environment. Moreover, on the double-story house, the upper floor has the function of thermal insulation for the ground floor.
Low-E glass and gray films for building windows are considered to have an effect of cutting incident solar radiation without intercepting of visibility through windows. We analyzed of spectral transmittance and spectral reflectance of gray films for building windows considering the change of incident angle of solar radiation against vertical glasses. As incident angle of solar radiation increases from 0° to 70°, spectral transmittance increases. And also we clarified its effect on decrease of room temperature by numerical simulation. In the case of a building with an atrium which is located in Kashiwazaki, Niigata, whose total floor area is about 800m2 and whose south wall is covered with windows, solar heat gain was reduced 55% in summer seasons, and 46% in winter seasons.
A new assessment system named CASBEE-HI (Comprehensive Assessment System for Building Environmental Efficiency on Heat Island Relaxation) has been developed for evaluating the effects of various countermeasures related to building design on heat island relaxation. In CASBEE-HI, environmental efficiency concerning the heat island relaxation (BEEHI) is defined as QHI/LHI, where QHI is the quality of outdoor thermal environment within a building site and LHI is the loadings emitted from this building site to increase the heat island effects in its surroundings. To assist the evaluator to examine the wind environment, two different scale wind environment databases were developed. In the present paper, wind environment databases for Tokyo and Osaka are described. The present Tokyo database includes results of three-dimensional CFD analysis in which all the existing buildings in the special 23 wards of Tokyo are reproduced in three-dimensional geometries in a grid network of approximately 500,000,000 meshes with a spatial resolution of 8 m in the horizontal directions.