Creep test of Fc100N/mm2 concrete and strain measurement of reinforced columns in an actual building was performed and creep strain with structures building was considered. As a result, creep factor obtained from creep test by a test piece was revised according to sectional form, and when adding elasticity strain and creep strain which form every structures flame building on each floor, it was confirmed that it’s possible to predict axial strain to construction load.
It is important to develop an information traceability system on the process of concrete production. One method is to record the information about the concrete production with IC-tags, and to install them inside the concrete. This method has a characteristic to keep the information inside the concrete itself. On the other hand, this method requires communication performance between IC-tags inside the concrete and the reader outside the concrete. The communication performance of IC-tags installed inside the small-size specimens was clarified in our previous study. This paper describes a study on the communication performance of several types of IC-tags installed inside the large-size concrete specimens.
After a disaster, it is needed to provide large amount of temporary houses promptly for people who lose their own houses. In this paper, a housing construction technique that is suitable for Japanese historical surroundings is proposed. It is making use of the Japanese plaster technique inherited for hundreds years. And the frame of this system is the shell structure that is one of the most efficient structural system, therefore, it can be built with very little amount of material.
In order to clarify fundamental properties of the casting calcium carbonate with 60% fly ash content, the reaction property and the compressive strength are investigated. The result are as follows; 1) The reaction property of the casting varies with different types of fly ash. 2) In the case of using fly ash, which has more amount of CaO, the casting has less the rate of water absorption. 3) Initial compressive strength of the casting is less than 10N/mm2. But the casting acquires the compressive strength more than 40 N/mm2 as the carbonation proceeds.
The IC tags assisted inspection, information recording and tracing system was developed. In the system the IC tags were used as to give permission for conducting inspection and to give codes to receive and record information. The practicality of the system was verified on the construction site of the steel structure. The system worked well as to assist the inspection works but it required a certain amount of extra pre-works such as database preparation and IC-tags installation to the steel members. The system also required additional time in conducting the inspection works compared to the conventional inspecting methods.
The mortar spreading method, to which the high density lithium nitrite solution added, applied actual size substrates were exposed along the coast of Okinawa and the repression effect of salinity infiltration was evaluated. This method had repressed the infiltration of flying salinity form the Sea for approx. 15 years. It was estimated that the salinity infiltration had been repressed because pores in the mortar had become finer and the gap had been filled with the water. Moreover, it was confirmed that little sub-nitrate ion in mortar eluted from the surface of this mortar and diffusion factor in the mortar was low.
Very fine plastic shrinkage crack is often reported to occur on vacuum processed concrete slab, which is considered due to cement-richness of a surface layer. A shrinkage-reduction admixture is used in order to prevent such plastic shrinkage cracks. Although the cracks can be avoided by this method, white powders of CaCO3 sometimes appear on the surface. The effects of the admixture and curing condition were investigated on the amount of powders and the bond strength. It was found that appropriate addition of the admixture successfully reduces the plastic shrinkage cracks without producing powders on the surface.
A technique is proposed to estimate probable maximum loss based seismic performance of reinforced concrete buildings using three dimensional elasto-plastic analyses and Monte Carlo simulation. It is difficult to analyze damage of the buildings in detail to achieve a target seismic performance using usual PML estimation methods. The proposed technique enables us to analyze loss of structural and non-structural elements separately. As these analyses enable us to identify the structural or non-structural elements that the most loss are caused by, we can update structural design efficiently. PML of two example buildings are calculated to compare seismic performance of these buildings.
We carried out benchmark tests for the strong motion simulation methods using various theoretical methods (the wavenumber integration method, the discrete wavenumber method, and the thin layer method). All the results generally show good agreements, but the results for damping media show large discrepancies, especially in the later phases at very far stations. This is because the most methods used the quality factors of the complex parts of the medium velocities, whereas one method used the factors not only in the complex parts, but also in the real parts, in order to satisfy the causality condition in the waveforms.
We performed a benchmark test for the strong motion simulation methods using stochastic Green’s function method. All the results calculated by six teams from different institutions generally show good agreement to each other. Since random numbers are used in generating time histories and so on, synthesized amplitude shows variation in particular frequencies. When applying the stochastic Green’s function method, this variation should be in mind.
This report describes improvement of numerical precision of the thin layer method, an effective tool to evaluate theoretical ground motions in flatly layered soil, as a follow-up on the previous paper, Part-1. We focus on some numerical improvements, i.e., different damping factors for S- and P-waves of media, tuning factors of consistent and lumped matrices. To precisely evaluate the first order differentiation of displacement in terms of depth direction, needed in the calculation of couple source solutions, a higher order approximation of displacement field is incorporated. These are validated by site responses of flatly layered soil subjected to obliquely incident SV-wave and dislocation point source.
Non-linear interaction between the soil and foundations is one of the means to affect the seismic responses of structure. Focusing on the ductility of the fibers and the elasticity of rubber-chips, authors have developed an artificial geo-material, which is stable up to a high strain region, by mixing cement, rubber-chips from scrap tires, and fibrous materials. This paper discusses the shear mechanism and the properties of the compound based on laboratory studies. Authors also expect that this compound would effect on reducing the environment load since it is made of scrap tires and waste soil generated in construction sites.
We performed a benchmark test for the strong motion simulation methods using numerical methods (finite difference method and finite element method). All the results calculated by six teams from different institutions generally show good agreement to each other. We found minor differences are generated by the choice of property on the grid just at the boundary of layers. The performance of absorbing zone makes differences in terms of artificial reflection waves from the model boundary.
We investigated the disagreement of predicted long period ground motion using two 3D velocity models and searched for the cause of this disagreement in the 3D models. VE of the predicted long period ground motions by Tokai-Tonankai Earthquake vary 50-100 cm/s in period of 5-10s at Yokohama, Shinjuku and Chiba. Different models of seismological bedrock at basin edge and basin structure in Sagami-bay produce the disagreement of the calculated ground motion. For now, several 3D models are proposed, which shall be compared and the differences of predicted long period ground motions shall be grasped from the point of view of structural response.
We constructed a database from published materials and other data on base-isolated buildings. The database contains some items that have not been analyzed before, for example, clearance and design earthquake waves which show the performance of base-isolated buildings. Using the constructed database, we analyzed the present situation and trends of base-isolated buildings in Japan.
Recently, vibration control devices are often adopted in Japanese buildings. Then, the seismic behavior of the buildings with them should be seized in the design stage accurately. However, that accuracy is not enough because the test data and analyses of the full-scale building are insufficient. This paper presents the 3 dimensional simulation of the experiment of the full-scale 5-story steel building using steel dampers conducted by E-Defense in 2009. Although the analysis results agreed the test results almost well, some differences were seen. Therefore, additional analyses were performed to study the effect of used models and parameters.
In order to investigate the practical use of the seismic deformation method in liquefiable ground, the questionnaire was conducted for structural engineers. The following were concluded. The ground deformation was not considered for the secondary design in the lateral resistance of the pile foundation. There was a difference among structural engineers for the estimation of ground deformation and the reduction of soil reaction spring. A simple design method that is considered of the effect of ground deformation will be needed for aseismic design of the pile foundation.
Based on past field test data on the horizontally loaded single piles, the authors have proposed a p-y model, which relates unit subgrade reaction force and pile displacement, for single piles. Particular attention was paid to evaluate the coefficient of horizontal subgrade reaction taking the pile diameter and the soil properties into account. The hyperbolic model presented in this paper shows good applicability to simulate the non-linear response of single piles subjected to horizontal loads regardless of the types of piles and soils, which can be useful for the advanced seismic design of piles.
Existing traditional houses have high risk of collapse during severe earthquake ground motion and the results of the seismic diagnosis are far below the required values in the Building Standard Low. However, renovation for earthquake-resistant structures is not carried out smoothly. It is one of the causes of that owners cannot imagine the relationship between seismic reinforcement and its effect. This paper described a performance evaluating guide to promote seismic reinforcement of traditional houses.
This paper elucidated two problems to calculate the structural performance evaluation of the moment resistance timber frame (“frame”) with a vertical load by structural analysis on actual design. Problems as follows; ultimate strength of the frame that connection is brittle, and frame structural performance that critical section position of columnbeam connection is not on structural axis. For numerical analysis, it is confirmed that ultimate strength of the frame is fallen because of a vertical load, and critical section position should evaluate appropriate position for each connection specification.
In this study, bending tests of continuous footing foundation reinforced by the several kind of seismic retrofit constructions were carried out. The retrofit constructions used in this study were made by additional concrete casting and carbon fiber sheet reinforcing. The tests were carried out by the three-point bending that has 3.6m length spans. The specimens whose beam and footing retrofitted by the additional casting had equivalent seismic resistance as the reinforced concrete foundations. But the other specimens didn’t have enough seismic resistance.
This paper describes analysis of observed seismic records and their simulation using a 3-D frame model for the traditional wooden temple, Higashi-Honganji Goeidou. From the records, the first predominant frequency decreases with increase of deformation. The seismic response of the top is much greater than that of the bottom. The response of west side is about half of the east side, due to the mud walls. The 3-D frame model was configured on the basis of the results of investigation and shaking table tests. The simulation results show good agreement with the records.
The effect of the strength prediction accuracy on the evaluated values for the duration of load (DOL) factor was discussed particularly for the engineered wood products. When the dead load for the long term loading test is determined basically by multiplying the stress ratio to the average material strength the DOL factor will be inadequately evaluated. And the wide distribution of the strength properties will cause higher DOL factor. The DOL factor was well evaluated by adjusting the stress ratio of each test specimen by considering the time to failure characteristic of the test specimens.
This report describes about development of wooden panels rahmen construction that considers construction of site. The development policy was assumed to be composed of a light material, high strength and high rigidity, and long span beam. Developing excellent rahmen construction in construction on the site became possible by composing the rahmen engine frame of the wooden panel. It was confirmed that wooden panels rahmen construction had an enough rigidity for a horizontal and vertical load. And it confirmed it by the experiment.
This paper examined the validity of electromagnetic radiation test to find an internal loss in columns of Japanese traditional wooden temple, Kiyomizu, in Kyoto. First, the test was performed for the specimen. The results showed that the test was able to detect 10cm over internal loss. Secondly, the test was performed for the column of Kiyomizu and some deteriorated columns were found. Finally, the earthquake response analysis was conducted for the Kiyomizu model which was assumed internal loss. In the result, the internal loss which exist column bottoms has minor influence on the seismic performance of Kiyomizu.
The solution of lacks in strength and rigidity is required of conventional wooden frame construction. Newly developed bolt with drift-pins increases strength of beam with dovetail joint in above construction. By using dovetail joints, we can use almost similar method to conventional frame erection. Pipe substituted for tenon with drift-pins joins column to beam on account of continuous beam type. Newly developed software for CAD and CAM leads to drawing for precut, quality control and boring by machine under the discussion with structural designer. Test results of full sized joints show that above reinforcement gives above construction required strength in structural design.
Aluminum seismic retrofit frame can be easily installed from the outside to an existing wooden house. And, aluminum seismic retrofit frame can suppress a big transformation without closing the opening under the earthquake. In this report, first of all, the performance of the aluminum frame was requested by experimenting on a joint part and the frame. And, the performance of aluminum frame of various sizes was requested by the analysis. Finally, the thing that the seismic force was able to transmit to aluminum seismic retrofit frame was confirmed by the structure study.
This report proposed a high racking resistance and high rigidity wooden glued panel. And, it is what examined about a basic performance. The specification of this panel is the wooden glued panel that bonding connected the plywood of 9mm in thickness to both sides of the frame material. The bending stiffness evaluation was able to be applied by the Kikuchi’s law. And, we were able to achieve wooden glued panel that had a high racking resistance and a high rigidity. The shear stiffness of bearing walls with opening was able to be applied by the sheathing area ratio.
The demands of building owners have changed in recent years: they now wish to be able to continue using buildings with small repair cost even after a severe earthquake. A building system with dampers is one structural type which meets these performance requirements, for which the dampers need good performance and applicability. The RC brace damper using the de-bonded axial rebars is one of the solutions. The tested results for the RC brace dampers showed good performances as damping members. A Frame test showed excellent performance for the building system.
Recently, RC buildings with core wall structures have been constructed. The coupling beams connecting core walls are possible to be failed by bond splitting during an earthquake. Short span beams using SHCC (Strain Hardening Cementitious Composites) with PVA fibers have been developed to improve brittle behavior. In this study, cantilever-shaped specimens were subjected to bond splitting tests to investigate bond characteristics of SHCC beams. The experimental bond strength shows higher value than calculated strength by conventional formulas for RC beams. The effect of SHCC can be expressed by modifying the term of lateral reinforcement ratio in these formulas.
In the series of experimental studies concerning low strength concrete members, it was pointed out that the flexural and shear strength of members with plain round bars was lower than the calculated values. This result is due to the occurrence of bond slip failure before yielding or shear cracking. A calculation flow to obtain the strength of the RC member with low strength concrete and plain round bar is proposed. This flow is verified with data of the previous studies.
For the central stations in big cities that serve regional area, it is impossible to discontinue the railway operations and difficult to transfer the railway tracks. The passengers’ safety and convenience need to be secured at first in order to start the development of the stations. This paper describes the case of JR Hakata Station project which solved such issues in the large central station development which were restricted by urban conditions, using various structural methods and techniques.
When strengthening historic unreinforced masonry structures, it is important to preserve their appearance. Considering that mortar joints are the weakest part of a brick wall, we proposed a new repair technique using the injection of epoxy resin into these joints. The proposed method is to inject low viscous epoxy resin into the mortar using a very low pressure. This paper presents the results of the fundamental loading tests with brick elements and brick walls. Based on the test results, the following conclusions were made. (1) An increase in the strength of the element was observed in each test. (2) The effects of epoxy resin injection were confirmed in the brick wall without the axial force.
It is known that the axial strength of composite columns could be calculated by the strength superposing method due to the many experimental results of axial compression of composite columns. However, in case of the composite columns in which recycled concrete are used, the contribution of the confinement effect to the structural performance has not yet been clarified. Therefore, twenty-one composite columns were tested under axial compression loading to investigate the effects of concrete type, such as normal concrete, recycled aggregate concrete and fiber reinforced concrete. The application of recycled aggregate concrete to the composite structures are discussed in this paper based on test results.
In this paper, we developed a crowd simulation model using the ellipse-based RVO model and compared theoretic models based on observation in order to represent high-density crowd walking. In the case of one-way pedestrian flow, the ellipse-based RVO model represented crowd walking at the density of 5.5 people per square meter. In the case of two-way pedestrian flow, the ellipse-based RVO model represented opposed flow at the density of 3.0 people per square meter while the RVO model which was the existing circle-based method did not occur opposed flow.
The likelihood of structural collapse of fire involved wooden buildings was analyzed by using the results of 22 existing full-scale fire experiments. This analysis is intended to provide firefighters with warning information of structural collapse during their activities. The occurrence of structural collapse was related to the macroscopic behavior of fire observed from outdoors. Onset of window flame and entire burning of the building were found as the two important signs which take place in advance of structural collapse.
It is very important to reduce vibration caused by train running for the station building which included railway tracks. Floating slabs as isolated tracks were used to avoid the problem of structure-borne noise in new Hakata station building. In order to replace tracks of commercial line to floating slabs, for example the steel girder fastened rails directly were used and special travelling cranes were designed to remove the temporary steel girders. As results of vibration measurement, the floating slabs turned out to reduced the vibration level on the station building floor by 25dB.
The method of the experiment is to use total of six color, three primary color (R,G,B) and three mixed color (Y,C,M), and to change the purity (increasing and decreasing method) of it to find the difference in the unpleasantness during working through measuring the perception towards the light color. As a result, like the result in the previous research, the unpleasantness during working increases and the purity of the light color increases, and the fact that there is a range that doesn’t feel unpleasant within the range that color can be perceived. In addition, the evaluation result of the range that color can be perceived including the stimulus range and the evaluation result of the unpleasantness during working are plotted in the CIE 1931 xy chromaticity diagram.
Cooling system had been installed for all metropolitan high schools in 2008 to improve indoor thermal condition and to increase learning efficiency of students. On the other hand it raises energy consumption and CO2 emission. In order to resolve such problems, thermal performances of building envelop such as insulation and solar reflectance should be improved. This paper presents the results of filed measurement about indoor condition of class rooms which are applied various countermeasures to find out adequate method to realize better indoor condition with lower energy. High reflective roof can decrease heat emission from it to urban air. The heat load calculation was conducted to study appropriate method to make indoor comfortable.
The performance of the envelopes of housing has been improved along with the promotion of energy conservation as national policy in response to the Kyoto Protocol. However, the levels of expectations for housing comfort by residents have also been increasing. In this paper, thermal environments and air conditioning behavior in housings compatible with the Energy Saving Standard of 1999 were investigated.
Recently, high-albedo materials and products have been developed to lower the surface temperatures of urban building roofs and roads. In this paper, outdoor exposure experiments and a numerical simulation are conducted to identify the effectiveness of reflective paint. The optical and thermal properties of 137 kinds of reflective paint are measured according to JIS (Japan Industrial Standard) method. In addition, sensible heat emission and heat load are calculated considering a change in the paint performance deteriorated by outdoor exposure.
Attic moisture control is one of the key issues addressed by the hygrothermal design of wood-frame houses. In general, exfiltration and natural ventilation are recognized as the main factors in determining the hygrothermal behavior of an attic. In this paper, whole building HAM analyses for predicting hygrothermal behavior were implemented to study the design value for attic moisture control. Over 30 cases taking both the equivalent opening area of the attic and the airtightness of the ceiling into account were examined. Results of the analyses indicated that the current guidelines regarding the equivalent opening area and airtightness are required in cold climate regions of Japan. However, it was also found that these guidelines may be relaxed in regions with milder climates. Additionally, it should be noted that the design value for attic moisture control was derived from the calculation results.
A study on natural heating and cooling system in a wooden experimental house is as follows. First, we made a floor cooling experiment with the rainwater cooled by underground heat in summer. Next, we made a floor heating experiment with the rainwater warmed by solar heat in winter. As a result, in summer the temperature on the floor fell by about 2 degrees and in winter rose by about 10 degrees.
The maintenance records at a certain large-scale hospital, the total floor area 75,311m2 hospital building and 12,793m2 health checkup center, are investigated. The monthly and daily data of electricity, gas and water consumption are obtained. The paper presents the features of the hospital and the outline of the buildings at first, and then annual or monthly electricity and gas consumption, including CGS operation results, and water consumption are analyzed. Then, using the daily data, the correlation between the energy consumption and the enthalpy of outside air, the difference of the data on holidays, and the annual characteristics of energy and water consumption at weekdays are presented. The paper also shows the daily maximum electric power and the restraint kW-value for the electricity demand management.
This paper introduces a comprehensive assessment tool of the built environment of cities, referred to as “CASBEE-City”. The tool supports local governments and other stakeholders in identifying environmental, social and economic characteristics of their cities and to quantify the effectiveness of city-led policies. As for the other CASBEE tools, CASBEE-City also implements the concept of environmental efficiency and allows evaluation of a city from two aspects simultaneously: the aspect of decreasing negative environmental load emitted outside the city, and that of improving environmental quality and activities inside the city. It is expected to contribute to the realization of sustainable cities.
This study aims to explain the effect of land use and local insolation environment on surrounding air temperature in mountain area. In summer of 2008, we measured the thermal environment in Fukutomi town surrounded by mountains. The insolation environment was estimated by GIS based on the sun orbit. As a result, we confirmed the difference of air temperature variation both in the morning and evening because of the difference of insolation environment in each measurement point around. In addition, we found that not only land use but also diurnal insolation environment affects the air temperature at night.
We made an environmental information system for occupants of buildings to reduce cooling/heating load. We focused on the aim of function is calculation data provide them to know whether they can use natural ventilation or not. It is called “recommendation mode for air-conditioning”. The system is collecting the data from HVAC on the BAC-net (TCP/IP) by using web server (Windows IIS, DB: SQL) and provides occupants to know the mode using their PC monitor in real time.
This study develops an environmental information visualization system for supporting thermal environment design in city planning. This system is constructed on a all-purpose GIS software. As visualization methods of 3D models, wire frame, surface model and solid model are applied according to a target scale or the characteristics of environmental information. The developed system is able to display urban planning data, landscape, thermal environment and historical data in multi-scale and multi-temporal using the 3D GIS.
Kobe-city government has made an effort to adopt ecological architecture methods into public buildings from 15 years ago. As result, many ecological buildings have been constructed, but environmental effect and maintenance conditions of those ecological architecture methods aren’t made clear enough. So we have carried out the survey about those matters by questionnaire’s papers and hearings to the caretakers of those public buildings. In this paper, we report the results and its study.
Though children are user for school building, they suggest limited place (toilets, signboard, biotop etc.) when new school building is designed. It is desirable that designers accept children’s view. This paper reports the simulation of using classroom with card game by children. The card game is able to draw out the children’s actual needs for facilities and goods, and get the concrete usage. Children can express their opinion easily through playing card game, and suggest various usage.