Particle geometry of aggregate used in concrete is fully expressed in terms of three independent properties: form, angularity (or roundness), and surface texture. In this study the author proposed an evaluating method to integrate the three shape characteristics into a shape index using the specific surface area and mean particle diameter that are measured by the permeability test and the sieve analysis test, respectively. The shape index is able to include the surface texture of particles, and to evaluate the shape of mixed aggregate with fine and coarse aggregates.
In this investigation the trend of research on accelerated carbonation of concrete and the changes in the conditions of experiment were followed in Japan. A survey on the history of the standards of test for concrete was conducted in time series, a flow of enactment and revision of the standards was followed. In addition the test condition of JIS was compared with those of European methods and on the application of the standard of accelerated carbonation test for concrete, a statistical survey of the requested tests was conducted.
In order to verify frost damage resistance of Lightweight concrete type 2 supposed to be poured to roof slab of high buildings at winter season, the authors have investigated by accelerated experiment on 1,000 cycle’s freeze-thaw in atmosphere, and by exposed experiment during 4 years at outside in cold areas. As the result of accelerated experiment, relative dynamic modulus of elasticity was over 100% for the concrete specimen covered on surface, and around 90% for the specimen no covered. And as the result of exposed experiment, it was over 100% for the specimen no covered.
Until now, demolition work has been upgraded about technical matters and qualification system. However, actual state of demolition work from Engineer and skilled worker’s standpoint has not been fully elucidated. Therefore, the purpose of this study is to investigate the actual state of demolition work by the questionnaire survey targeted to subcontractors. As a result, this paper showed the actual state of demolition work about preliminary survey, calculation, consciousness of accepting order and contract system, construction scheme, construction control and human materials.
The authors developed a system to improve the performance of construction supervisors. The system provides an image which shows the situation of currently working top-floor to computer monitor of supervisor. Cameras are attached on the tower- crane, and the raw-images from cameras are transformed and assembled by the program. The system was used in actual site and evaluated in term of practical utility. According to the result, the authors confirmed that the system describes images of working top-floor which supervisors can recognize the situation without physical observation.
Investigating the degradation state of coating of Tokyo Tower has been conducted about ten times till today since the completion in 1958. After that, continuing partial investigation suitably, investigation mainly concerned with viewing from four years every six years is conducted, and the necessity of repair coating systems is judged. This paper reports the results of an investigation carried out for the purpose of assessment of the situation for coating systems of the incidental institution of a steel tower main coating systems (galvanized steel and steel).
In connection with a rise of the global environment of these days and concern about extension of life span, examination of repair coating specification which considered reduction of VOC in coating systems of Tokyo Tower has been needed. In order to consider future VOC reduction, test construction of the water paint system, and continuous evaluation has been carried out over in 2006. This report the circumstances which selected the future repair coating system based on the evaluation result of the construction nature of a water paint system, and durability which performed test construction.
This paper presents a technique to evaluate regional differences of loss ratio of building damages caused by long period strong motions. Loss estimation is important, since the impact of building loss on the business must be evaluated to construct business continuity plan. Loss ratio of model buildings are calculated by 3D elasto-plastic response analyses using long period strong motions in consideration of response spectra variations. Regional differences of two kinds of high-rise buildings have been analyzed against huge Nankai trough earthquake. The proposed technique has revealed regional differences in the magnitude and the type of building loss, and the measures.
Vibration characteristics of a high-rise building has examined by microtremor observation, free vibration test and earthquake observation. Natural frequencies and damping ratios for lower modes are estimated by microtremor tests, free vibration tests with AMD and man-powered excitations. Natural frequencies are shown to be lowered approximately 2% comparing to the situation soon after the construction. Relatively low damping ratios less than 1% are stably obtained. Amplitude dependent characteristics are slightly observed in estimated natural frequencies. Vibration characteristics during low-level earthquake response are estimated. Obtained properties during several years are effective for structural health evaluation after the large earthquake response.
The method for estimation of foundation-input-motion based on ambient vibration tests is presented. In the proposed method, several theirs of construction are averaged to estimate foundation-input-motion. But, if we average them simply in frequency domain, we obtain foundation-input-motion which is affected by superstructure. We exclude affection of superstructure by using Fourier-spectral-ratio of top-floor’s per basement-floor’s. Relation between estimation precision and number of averaging samples are discussed. Base-isolated buildings have isolated-layer between basement and superstructure. Therefore, inertial force of superstructure doesn’t affect foundation-input-motion of earthquakes. By using earthquakes data of base-isolated buildings, we obtain foundation-input-motion which is not affected by superstructure.
The seismic response behavior of five-story building structures composed of shipping containers was evaluated analytically. During shipping, containers are connected to each other at their cast iron corners with unique connecting hardware. Various benefits can be obtained by applying this connecting and stacking system of shipping containers to building structures, such as rapid construction time and low cost. The nonlinear analytical models included the contact and friction behavior at the connections. Under multiple earthquake ground motions, the structural damage was found to be limited, suggesting that the use of shipping containers to create safe building structures is feasible.
We performed high density microtremor measurements and earthquake observation for a mid-rise RC building which is prepared for seismic retrofitting. S-wave velocity profile of surface around soft ground is estimated and the soil-structure interaction effect on the dynamic characteristics of the building is indicated. Based on the high density measurement, we estimate that the foundation-input-motion and denote the complex three-dimensional vibration characteristics including out-of-plane deformation of the first floor slab.
Seismic observation in Japan has drastically developed in the recent 15 years. Besides thousands of stations on ground surface for seismic intensity and ground motion, a number of earthquake response observations of buildings has been developed for data accumulation and structural health monitoring. However, the reality of the earthquake observations of buildings, such as the actual number of observed buildings and the used equipment, is not exactly clear. In this report, the current status of the earthquake observations of buildings is discussed based on the newly developed database, as well as the future scope of observation and data utilization.
The purpose of this study is in order to grasp the behavior of rubber bearings in strong motion by using the three-dimensional analysis model. It was confirmed that the axial force of rubber bearings received not only the earthquake ground motion but also the influence of the building shape. Because effective area of rubber bearings supporting isolated buildings is decreased by horizontal deformation, the axial force acting on effective area becomes large. The axial force evaluation method which is used in this paper is effective in most cases, but it is necessary to note it to become undervaluation in part.
This study investigates the dynamic responses of a super high-rise residential building during the 2011 off the Pacific coast of Tohoku earthquake and its pre- and after-shocks based on temporally consecutive nonlinear response analyses. The missing input motion records during the main-shock are compensated from the soil-pile-foundation interaction analysis and records at the tip of piles. The earthquake response simulation is compatible well with records in the building. Distribution of the maximum story drift angle is also discussed in related with the actual indoor damages.
Pulling test was carried out in order to examine the pulling out characteristic of permanent ground anchors of compression type having a large diameter settled in hard clay and soft rock. It was found that the level of the ultimate frictional stress was equal to the value of anchors which has usual diameter in the past, and the ultimate frictional stress was possible to presume by using the value of undrained shear strength, and the displacement of anchorage zone at the pulling out time was about 10mm.
The grid-form deep mixing walls method is one of the liquefaction countermeasure methods. In order to design the grid-form deep mixing walls, it is necessary to carry out seismic response analysis with FEM model based on the result of soil investigations. Few geotechnical engineers can design the method because it is difficult to conduct of the analysis. In this report, the simplified evaluation tool is introduced that the effect of the liquefaction countermeasure can be judged. To confirm the effectiveness of the tool, Dcy values considered the effect of grid-form walls are compared with settlements of centrifuge model tests.
By the 2011 off the Pacific coast of Tohoku Earthquake, a great amount of disaster waste and tsunami deposit was produced. Authors aimed to apply the research findings to reclaimed ground for residential land using useless disaster wastes. In this paper, laboratory element tests were performed to verify the mechanical properties. The test results shown the values of stiffnesses and hysteretic damping ratios of geomaterials were depending on the mixtures materials, and compressive strengths increased substantially due to accretion of the density using such as mud as tsunami deposit.
This paper presents an equivalent pier method, in which three kinds of spring (kb at the pier base, ks along the pier shaft and kc of the pile compressibility) are used, for quickly and easily calculating the vertical spring of pile groups subjected to vertical load. Parametric studies of pile groups varying parameters, such as pile spacing, pile length, Young’s modulus of soil and number of piles, were performed. The validity of the vertical spring of pile groups using the equivalent pier method was examined by comparing with the results of hybrid analysis of pile groups.
The purpose of this study is to define hysteretic characteristic model of nuki-column joints of Japanese traditional wooden frames using extended NCL model. Based on the results of static cyclic loading tests, typical characteristic loop shape of joints was determined and the formula for determining shape of skeleton curve of joints was proposed. By coupling the typical characteristic loop and the calculated skeleton curve, the extended NCL model for nuki-column joints was defined. It was confirmed that the analysis results of hysteretic energy dissipation by the proposed model showed good agreement with the experiment results.
In this study, the strength and deformation relationship of mud walls is estimated from the results of element tests for each wall clay which consists of mud walls. Full-scale static lateral loading tests for various types of mud walls with initial failure in shear are performed. Element tests are also conducted to grasp the material characteristics of each wall clay. The estimation results are compared with the results of full-scale tests, and the accuracy is examined.
In this paper we described the structural performance of the moment resisting beam-column joint for glulam. The connection is composed of a couple of columns and a beam with wooden dowels or screws, so it resists moment by fasteners’ shear resistance and embedding to beam with columns. The structural key issue of the proposed joint is fracture of beam caused by a loss of section modulus. As the results of the moment resisting tests and calculations, the initial rotation stiffness and yield moment were predicted, and influencing factors were observed.
Wide width beams are frequently designed in R/C moment resisting frame. Using mechanical anchorage for such beam reinforcements, development strength of a part which is not able to anchor in column section may be deteriorated. In order to solve this problem, the authors proposed new reinforcement detailing. In this study, R/C L-shaped joint connected with wide width beam using mechanical anchorage is tested. Consequently, the authors clarify ultimate strength and beam end ductility of these L-shaped joints.
Effective utilization of 590N/mm2 class high-strength reinforcement is able to reduce number of footing beam reinforcements. However its validity is not verified by experiment. In this study, R/C L-shaped joint using 590 N/mm2 class high-strength reinforcement and mechanical anchorage is tested. Consequently, the authors clarified that the proposed design formula can be applied for estimation ultimate strength of such joint as well as using normal-strength reinforcement.
Based on the actual procedure for retrofitting designs of the 5-story school building in N university, the effect of variations of facade design on seismic performance was investigated through static and dynamic response analyses. The X-shape appearance of retrofitted model showed 108% strength enhancement against that of non-retrofitted model. This facade design was choosen in the use of the actual retrofit of the building, corresponding to the analytical results.
This paper proposes a new hoop arrangement for mechanical splices in RC columns. Pilot tests were conducted using two RC column specimens with/without mechanical couplers where the proposed hoop arrangement was applied. As a result of cyclic loading tests, the proposed hoop arrangement did not significantly affect the column shear performance, namely, damage under allowable shear stress and ultimate shear strength. Feasibility of the proposed method was experimentally verified for practical application.
This paper describes the results of experimental study on effect of lateral restriction of prestressed concrete poles using high strength concrete about bending deformation performance. I paid my attention to two types for lateral restriction and performed bending tests for external force to twice the design load. As a result, according to each form, I found two types at the time of destruction and found the force-drift angle relationship and the maximum ductility factor with ability of energy absorption. I particularly clarified the difference in deformation performance after first crack occurred.
This paper proposes an evaluation method for the eccentricity shape factor (Fe) of moment-resisting steel frames. The model used is a multi-story building with uniaxial eccentricity, for the unbalanced stiffness and shear strength characteristics are simulated. The evaluation is performed by individual calculations for the deformation of every story as the deformation angle is increased to its limit. The results of elastic-plastic 3D analysis show that the evaluation method for Fe provides an appropriate representation of the influence of eccentricity.
Investigation on the relationship between seismic damage to non-structural elements and structural characteristics is one of important issue to consider mitigation method of seismic damage to non-structural elements. In this paper, relationship between structural characteristics of school gymnasiums and seismic damage to non-structural elements due to the 2011 Tohoku earthquake and aftershocks is reported. In the investigation, seismic damage of ceilings, windowpanes, outer walls, and inner walls were observed. Such damage is directly linked with serious damage to a human body.
There is a great demand to the exterior supplemental steel brace for seismic retrofit, in order to complete the construction work while the building space is in service. The pre-stress is used as an installation method of steel braces, and the authorized design guideline is available. The reliability of this seismic retrofit method strongly depends on the existence of the pre-stressing force. There was an opportunity to adopt an exterior supplemental steel brace and the pre-stressing force was monitored in site for more than nine years. The reliability of this seismic retrofit scheme was confirmed.
In recent earthquake, most of new buildings doesn’t collapse but can’t guarantee a continued functionality after earthquake. This paper presents the case studies using 3 databases developed, which are damage evaluation, reparability evaluation and functionality evaluation, for post-earthquake resilient evaluation system. Regarding the result of reparability evaluation for hospital building, repair cost and repair time for each component are calculated. Regarding the result of functionality evaluation, post-earthquake scenario is shown for users lived in residential complex as seismic performance display.
The greatest feature of carbon fiber reinforced plastics (CFRP) is an overwhelming high-specific strength. CFRP can change architectural space innovatively. CFRP is a general material as one of the high-performance materials in other fields besides construction. Then, structural use of CFRP already has various track records such as airplane and automobile. Compared with other uses, the use period of construction is long, and higher durability is required especially of structural materials. In this research, experimental verifications are carried out for clarifying durability for the purpose of using CFRP expansively as a structural material of construction.
A series of sheathed timber-framed walls finished with wood are designed and verified against fire resistance tests for the development of 1-hour Quasi-fireproof construction suitable for large scale timber buildings. The results reveal feasibility of designs with noncombustible underlayer thinner than conventional rated designs and insignificance of seismic effect on the fire resistance of the tested designs.
To accumulate measurements of building vibrations, Sub Committee on Measurement and Analysis of Environmental Vibration and Goto laboratory at Hosei University have jointly carried out the measurement of building vibrations caused by conventional railway in a two-story wooden apartment house since 2003. In this period, for the purpose of replacing grade crossings with overpasses, the railway structure was shifted from ground railway to elevated railway. Since measurements were obtained between before and after making elevated railway, this paper focuses on the change in the building vibration characteristics and building vibration amplifications for ground-borne vibrations.
This study proposes a lighting method that reduces energy usage and improves evaluation of lighting environment. Method focused on planning the zone, changing lighting equipment and considering the surface of space. This method was applied to a renovation of a commercial building with multiple tasks. Comparing before and after the renovation, it proved successful in reducing energy usage, decreasing luminous flux, improving evaluation of the lighting environment, and physical quantities of the environment.
In recent years, research has been promoted into the improvement in workplace performance by the Workplace Productivity Research Consortium in IBEC,1) 2) and awareness of workplace productivity in offices has been increasing in Japan as a technically advanced country. The O building 3), which was completed in 2011, is a research office, in which various workplaces are configured to improve productivity; the dwelling environment including air conditioning systems is designed for application to that “location,” and verification is carried out in the operational stage. An outline of this work is presented as our knowledge of the importance of workplace productivity in the future.
The government aims a realization of Zero-energy-house till 2030. There are many existing houses where we should live for a long time in Japan. We have to think about a solution for the renovation intended to realize the Zero-energy in existing houses. In this research, two existing houses were renovated. One is a two-family house, and the other is a house for seniors. By monitoring them, it was found that we can save energy up to a certain degree. However, there are some problems to realize the Zero-energy, especially in this case.
The purpose of this study is to investigate the main factors of the air temperature distribution in basin city in summer. Hadano is a basin city located in Kanagawa. At first, authors measured the air temperature of 14 points in Hadano during the summer (July 13 - August 31) in 2011. As a result, the spatial distribution patterns of the maximum and minimum temperature are different from each other. In the analyses, authors picked green coverage, ventilation condition, amount of solar radiation and elevation, as main factors of forming air temperature distributions. As a result, daytime temperature is influenced by the ventilation and nighttime temperature is strongly influenced by green cover.
A study on natural cooling system by rainwater and underground heat with ready-made drums in a wooden experimental house is as follows. First, the temperature of rainwater before an experiment was about 15 degrees. Next, water temperature withdrew to about 16 degrees by underground heat in about 3 days after experiment. As a result of having used control of pump and tank, the room temperature maintained 24 - 29 degrees. And PMV maintained less than ±1. But, only by control of tank, we cannot continue this system.
Climate change such as global warming is proceeding and climate conditions have huge impact on building performance. Thermal calculation is conducted to adapt a building to climate conditions using standard weather data which consists of weather components such as temperature and solar radiation. At present, it is common to use standard weather data that are based on current or past weather conditions. However, most buildings have a lifespan of several decades, during which climate can gradually change. Therefore, energy simulations should incorporate climate change predictions in order to ensure that buildings are adaptable to future climatic conditions and have long-term building performance. The purpose of this study is to construct future standard weather data which based on the future climate conditions using dynamical downscaling method with GCM.
The supply situation of public rental housing by Hong Kong Housing Authority is clarified in order to grasp the present condition of housing supply in Hong Kong. About the supply situation of public rental housing in Hong Kong, the public permanent housing and the private permanent housing are 50 percent respectively, and the public rental housing forms 30 percent of the whole residence. About the supply situation of public rental housing by Hong Kong Housing Authority, reexamination of the new development of public rental housing and supply stoppage of subsidized home ownership housing are performed by conversion of the housing policy in 2006. As of 2012, the redevelopment project and the large-scale repair project of public rental housing which have been superannuated are advanced preponderantly.
In this study, it aimed to clarify about the floor planning and the feature of block type and flat type, in order to grasp the present condition and the measure of HKHA public rental housing in Hong Kong. The block types of Mark series from the 1950s to the 1970s, Slab series after the 1970s and Harmony series after the 1990s have been used in HKHA public rental housing. As each type of housing estates, Harmony series have been used in public rental housing, Trident in tenants purchase scheme and mixed block in home ownership scheme. In Harmony series, the flat types with different scales are put together complexly, and the number of bedrooms and the resident’s number are set up. Although the living floor area is held down to minimum, the lighting and ventilation for forming sanitary living environment are secured.
This is trial study on behavior tracking survey with the automated face recognition technology in group-living. 1) Different values were measured, even with the same behavior. 2) In “movement” and “appearance”, the average value at the time of direct involvement with the staff was significantly higher compared to that of noninvolvement. 3) Furthermore, the average value at the time of indirect involvement with the staff as seen in “TV-watching” and “Inaction” was significantly higher compared to that of noninvolvement. By utilizing this method, it suggests that the detailed research result can be obtained compared to the existing behavior tracking survey.
We have been used to the system of arrow signs so much that we sometimes ignore how inconvenient they are in a certain places like underground hypostyle entrance halls for railway stations. It is true that arrow sign system is quite useful in linear place like crossings in stations and malls, however, in planar space, it is not fully efficient in terms of wayfinding. In this paper, the authors propose 2 hypothetical sign systems for planar space, and experimentally examine their effects in wayfinding in the virtual environment. The results show: 1) polar / rectangular coordinate sign system is more effective in reducing time for wayfinding than the arrow sign system, and 2) the polar / rectangular coordinate sign system is also superior to arrow sign system from the viewpoint of spatial perception.
In Miyagawa Village, we can see many folk houses built by a construction system “TATEAGE”. We investigated “TATEAGE” how to construct. When rebuilding the folk houses from a thatched roofing to a single roofing, some existing wall posts were taken away and long new wall posts were set up. In most cases a space between beams grew larger. “TATEAGE” was constructed about 1900 - 1970.
The purpose of this study is to clarify the construction and the making process of the stone roofs in TSUSHIMA. The stone roofs are found in 5 areas in Japan. I could clarify that TSUSHIMA’s characteristic making process, by mutual aid of all parsons in the village, and techniques of making roofs using the different kinds, shapes, and thicknesses of stone.
We are aimed to clarify that the WS is applicable on individual architectural design project. For the purpose of proving the effectiveness of the WS method, the WS interactions were observed and extracted for the analysis. The raised comments were categorized according to 3 types. The relation between the raised comments and the progression of WS were analyzed. In addition, the post-occupancy evaluation was carried out. The result was analyzed with the aid of mathematical quantification theory class II to clarify the relationship between WS participation and the level of occupancy satisfaction.
First, we organized physical operations on design in the renovation of buildings, and quantify them. We define that as the degree of change. Next, we did the psychological experiments of visual assessment on renovation of buildings. We analyzed by using correlation coefficients and self-organizing map. And we considered to clarify the relationship of visual assessments and degree of changes on design in the renovation of buildings.
Our regional cities are always scared to big fire accident or earthquake every day. But the number of capacity of shelter does not increase, because budget shortfall of local governments might not take them in action. In contrast, Wide-area evacuation simulation can easily figure out the image to antagonize the regional urban disaster. And more, it can calculate the possibility of blocking escape route when the city is broken, and make safe evacuation plans before disaster occurs.
This report describes the process of material preparation to implement townscape measures of the Motokukuri District, which was designated as an Important Townscape Planning District, as well as planning conditions based on findings of a townscape survey. (1) By focusing on townscape components, we classified the Motokukuri District into six zones according to townscape characteristics. Among such zones, the “Zone with Settlements in Historical Environments” strongly characterizes the District and it is desired to utilize existing lives and traditions in improvement plans of the zone. (2) Residents are fascinated by nature and the traditional townscape of the District, but not by street components or the old elementary school building. (3) Regarding living environments, although satisfactions with “convenience” are low and residents have high demand for improvement. As for future images, residents tend to weigh comfort in life, history, cultures, and calmness. (4) In respect to original landscapes, the District has a strong landscape unity without differences among zones.