The architectures had been constructed with the solidified product of soil for the modern architecture in the developing country and the landmarks in all over the world. In the advanced country, the industrial method with soil is being recognized again. The industrial method with soil has the following features: 1) The long time and non-productive to construct, 2) It is easy to construct by human power, 3) Local production for local consumption. This study describes the results of tests aimed at finding out the material properties of soil materials for the construction of Hanchiku architecture. Some experiments were conducted to clarify durability, water absorption, design, strength and so on.
Concrete is delivered from ready-mixed concrete plants to construction sites in the form of unhardened half-finished materials. Proper strength and durability can be verified only after its hardening. Therefore, it can be said that concrete is a construction material that requires a traceability assurance system that is more meticulous than those for other industrial products. We are developing a technology to assure traceability of concrete by making use of the IC tag. This paper describes a study on the various information regarding concrete production/works recorded and maintained in the traceability system.
In this paper, equivalent age method and maturity method based on the temperature history of concrete were examined as strength estimation method for removal of sheathing. In strength development of two methods, it is relatively consistent in ordinary Portland cement, high-early-strength Portland cement. But there was a tendency that the difference was large in Portland blast-furnace slag cement (BB), Portland fly-ash cement (FB). Under the conditions of this report, the applicability of maturity method for FB was confirmed, but in application to estimating strength, it is necessary to consider the influence of kind of admixture and substitution rate.
In this paper, stress strain states around weld toe and deformation capacity limited by ductile crack initiation of cold formed SHS column to through diaphragm robotic welded connection using 25 degrees narrow groove are evaluated by finite element analysis. Analytical parameter is the shape of excess metal determined by the result of sensitivity analysis of stress concentration factor. As a result, there was a correlation between the stress concentration factor and the deformation capacity of column.
In general, the reinforcing bar of the CO2 arc welded joints, are using a steel backing material. However, the steel backing material melting and becomes integrated with the welded portion. For this reason, it is impossible to visually confirm the initial layer portion. Therefore, by painting a paint containing aluminum as a main component on the outside of the backing material, the paint discolored by welding heat input. By using this phenomenon, we propose that it can be visually confirmed. In the CO2 gas arc welded joint of the reinforcing bar, when the difference between thermally discolored width and root gap is less than 4.8 mm, it was found that the reinforcing bar end face was sufficiently integrated.
This paper deals with investigation in the actual state on the acquisition of qualified person and qualification allowance of concrete pumping worker in concrete pumping methods. Therefore we investigated special education, person taking a course of lectures, certified concrete pumping operator and register concrete pumping sent worker. Moreover, we conducted a questionnaire survey about qualification allowance of concrete pumping in Tokai area. As a result, Construction companies request deploying qualified person into construction sites, but in most cases Construction companies don’t pay pumping worker qualification allowance.
Longevity of building is highly essential from the viewpoint of Life Cycle Assessment (LCA). In order to promote the longevity of building, it is necessary to achieve three basic concepts: (1) assurance of safety and quality, (2) decrease of environmental load, and (3) increase of cost effectiveness of construction. This paper presents a case study to rationalize the maintenance priority for aging buildings. The proposed method is applied to maintenance for a nonstructural member of the large-scale industrial building such as thermal power station etc. As a result, the proposed maintenance priority judgment method was confirmed to a highly effective manner reducing both cost and environmental load in LCA.
This paper deals with the rust-inhibiting properties of patching materials containing chloride ion fixing admixture and nitrous acid type admixtures by the outdoor exposure of specimens modeling RC structure. As a result, the self potential of rebar differs from base and patch sides for the chloride ion fixing admixture. Such differences are considerably recognized for the nitrous acid type admixtures. Regardless of the self potential of the rebar, the corrosion of rebar is not recognized at the patch side. The macro-sell corrosion of the rebar is occurred in the base side, and increased with increase in the chloride ion content.
Repairing method using lithium nitrite for reinforced concrete structures under severe salt damage environment has been proposed. The authors evaluated the corrosion inhibiting effect for each repair method under presence or absence of neutralization and difference in indoor or outdoor environmental. We propose suitable repair methods according to each environmental condition.
Thin steel plates galvanized are used for steel-framed house, roof and wall and their metal fittings of building structures. Bolts generally used to join metal fitting have zinc galvanized specification which is classified into electro-galvanizing coatings of zinc on steel, hot dip galvanized coatings on steel. Corrosion occurs in not only metal fittings but also bolts, caused by the presence of moisture and oxygen, depending on the environmental conditions. The degree and form of the corrosion is different. In this paper, the combined cyclic accelerated corrosion test of galvanized bolts of the roof metal fitting and tensile test are conducted. Tensile strength of galvanized bolts under corrosion is evaluated.
Study on service of applied conditions and structure performance about members post-installed anchor used are being carried out. This paper reports on the influence of specimen size and testing condition on pull-out properties of post-installed anchor. And the follow conclusions were found: as for the mechanical anchor, pulling behaviors and maximum loads were similar, but these were different for the bonded anchor.
In general, it is difficult to calculate floor accelerations of main frames in non-linear seismic responses for seismic design of non-structural components. A formula to calculate them without time history analysis and eigenvalue analysis has been proposed by authors. Based on the formula, this paper verifies applicability of the formula to real building models and proposes a practical way of setting strength factor in the formula. By comparing the results by time history analysis, it is confirmed that the formula gives good estimation for floor accelerations.
Combination of image-sound-vibration integrated sensing and robust data transfer is used to construct a change detection system of building group in urban areas in preparation for unexpected events. The field test under severe condition has been performed in the remote island, Gunkanjima. Nine buildings on the island are selected to monitor the long-term evolution of damage and deterioration through sensor fusion of MEMS acceleration sensor network for vibration sensing, microphone array for sound sensing and surveillance camera network for image sensing. The overall framework and current situation of the Gunkanjima monitoring are reported and future perspective is presented.
This paper describes a simple model for analyzing the acceleration response of an elevator-type high-rise mechanical parking system in a high-rise building. It is based on a previously proposed 3D model, and involves both Voigt model representing the rubber dampers, and bending-shear elements representing two types of columns. The validity of this model is verified by comparing the acceleration response obtained using the previously proposed 3D model, which is an important factor when considering the business continuity plan for such parking systems.
The objective of this report is to estimate the indoor damages of super-high-rise residential buildings during the 2016 Kumamoto earthquake through a questionnaire survey for residents. The survey was conducted for 8 super high-rise residential buildings in Kyushu Island including three in Kumamoto City in late May 2016, about 1 month after the main shock. Intensity of floor shaking in Kumamoto City was much stronger than that in Kanto area during the 2011 Tohoku earthquake. Cracks in wallpaper were noticeable in the middle floors which is different from the Kanto case, partly due to different characteristics of input motions.
The purpose of this paper is to evaluate stiffness of a base-isolation layer and a super-structure of high-rise seismic isolated building from the earthquake response observation records with different amplitude levels. As a result, the stiffness of the base-isolation layer based on observation records was close to the design value. As the amplitude increased, the stiffness of the super-structure reduced - confirming the amplitude dependence of the super-structure.
Past study had proposed a design method for base isolated structure considering tensile strain. Therefore, this paper proposes a method to predict the tensile strain of laminated rubber bearings and the moment of beams due to superimposed horizontal and vertical responses using constant energy rule. This proposed method considers that the tensile modulus of rubber bearing is lower than its compression modulus.
The environment of structural design changes from day to day, corresponding to the development of computer tools. Recently “Microsoft Office Excel” installed solver which enables executing optimization problem. Moreover, “Windows Script Host” enables the user to automate operation process on Windows machine. By utilizing these tools, we try to introduce optimization methods to structural design in practice. Two problems are implemented herein. First is searching of optimal form of a bridge with tree structure system. Second is searching of optimal column position of a steel latticed shell roof.
The calculation method of horizontal soil spring for spread foundation proposed in this paper is able to assess horizontal soil springs of various individual foundation groups with considering interactions among spread foundations. In addition, the horizontal soil spring of the spread foundation with complex shape can be easily evaluated due to discretizing aggregate of circular foundation. The validity of the calculation method was confirmed by comparing calculated results against those of elastic finite element analysis and elastic theory.
The authors have developed tensegrity frames that are stiff enough, as a structural skeleton, to support a membrane roof. A tower and a truncated pentagonal prism tensegrities were designed and constructed successfully. The paper reports the progress of their design, structural analysis and construction scheme checked with 1/10 scale model test. The authors insisted to manual pretensioning through the construction and it required special careful plan for tension introduction scheme.
A safety net is an effective fail-safe measure against the accidental collapse of ceilings. However free-fall of heavy ceiling panels may induce a high impact load to the supporting point of the nets. In order to reduce it, the authors propose the shock absorbers using wire clips. To examine the effect of them, the authors have conducted some experiments and the results are shown in the paper. Some numerical analyses are also described. The results show the shock absorbers can reduce maximum tension the wires experience by about 40%.
The purpose of this research is to clarify double shear with force acting in the opposite direction of bolted joints with the steel side plates. Experiment verified the validity of calculation method of shear stiffness by theory of a beam on elastic foundation and calculation method of shear yield strength by European yield theory. And it was clarified that shear performance of double shear with force acting in the opposite direction and single shear are the same if the bolt length is more than a certain value.
Authors have developed a two-way flat slab system that is composed of double layered Cross Laminated Timber (CLT) in order that strong axial directions of CLT can be orthogonally arranged in the slab. Glued-in-rod (GIR) joint system is adopted for joining between the CLTs. Performance of GIR joint systems in several parts of the slab is investigated by using element experiments in tensile, and performance of CLT keyed beam for the CLT flat slab is investigated by using actual slab experiments in bending.
We developed a timber shear wall in steel frame structure and estimated the required performances to be introduced in the 5 storey building. Firstly, we designed the shear walls of this system to satisfy the requirements and conducted the full-scale shear tests to grasp the characteristics of the failure behaviors and the actual properties of the walls. Secondly, we proposed the analytical model and compared to the test results to verify the possibility for predicting them. It was concluded that the walls adopting Cross-Laminated-Timber could achieve the required performances and their mechanical behaviors could be predicted fairly precisely.
A response control technique of the central column of a timber five storied pagoda was successfully developed. It was demonstrated that response displacement of the central columns’s top would be reduced by 50% by the developed control vibration device installed between the structural frame and the central column. This technique was applied to a newly built timber five storied pagoda in Fukuoka. Earthquake monitoring to verify not only the analysis model but also effectiveness of the installed device has been performed since the construction completion. 3-dimensional analysis utilizing a non-linear frame model was compared with both the microtremor measurement and the two earthquake records.
This paper aims for developing a high strength diaphragm using mating connection of plywood. We made an evaluation formula of the load bearing wall with mating connection and compared it with the result of the full-scale experiments. From the results, we calculated the actual efficiency of the mating connections. When calculating the evaluation formula with its actual efficiency, the calculated value and the experimental value became close values. Future challenge is to elucidate the mechanism of its efficiency.
The purpose of this research is to clarify the influence of difference in size of horizontal diaphragm on shear performance. The subject of research is horizontal diaphragm reinforced with shear key along CLT joints. At first, we confirmed the influence of difference in size of horizontal diaphragm on shear performance by experiment. Next, we confirmed it by numerical analysis of many patterns. As a result, the influence of difference in size of horizontal diaphragm on shear performance was shown.
Authors focused on the roof frame of buildings as effective wood utilization parts. In order to realize timber framework by GIR joint system, we conducted several experiments to develop a method for evaluating joint performance and applied it to the assumed design model. In this paper we report on its contents.
We studied and developed tensile joint of wood with round bar steel and washer, which can be adapted in wooden king-post truss or wooden parallel chord truss and so on. Upon developing, we had conducted tensile element test and grasped the characteristics of those. In 2015, a revised edition of JIS A 3301-2015 (Design standards for wooden construction of school buildings), adopting these tensile joint of wood with pulling bolts in roof structure of king-post truss, was published.
We propose the completely non-destructive test using impact elastic waves for estimating the material properties of large diameter wood. In this test, splits in the wood have little effect on the measurement. We confirm the relationship between the surface and the cross section distributions of the wave velocity measured with the proposed test. Furthermore, we discuss the method to estimate the material properties based on the wave velocity of the wood surface. There is a possibility that the Young’s modulus can be estimated approximately by measuring 4 points equally dividing the wood surface in the circumferential direction.
In seismic retrofitting of existing building, concrete surface are chipped using an electric chipping hammer in order to connect retrofitting members to R/C frames. The roughened concrete surface has very complex concavo-convex shape. Therefore, estimating of the shear strength is very difficult. In this paper, we conducted the shape-measurement and shape-analysis of roughened concrete. In addition, the shear tests are also conducted. Using the obtained data, we tried to evaluate the shear strength as sum of strength by bearing stress and by local interlocking. As a result, it was concluded that the optimal area ratio rcr was about 0.3.
Database on the structural characteristics of super high-rise residential buildings are constructed based on documents for the 77 buildings used in the structural design. The masses, linear and nonlinear springs are statistically compiled in terms of normalized height-wise distribution using vibration analysis models for the 39 super high-rise RC buildings. Nonlinear earthquake responses of these buildings are evaluated using several input motions used in the structural design. Equivalent natural periods are found to increase 1.8 times from the initial condition for the level-2 excitation.
Less number of specimen with the shear span ratio of 0.50 or less were test, because it is extremely hard to set it up. FE analysis can resolve above issues. In addition, the concrete strength reduction (CSR) would be occurred for the vertical direction due to the bleeding and the aggregate sedimentation. In this paper, concrete walls with shear span ratio of 1.0 or less and the CSR were analyzed. As a result, the CSR and Qsu’ should be taken into account the seismic assessment in addition to a conventional concrete survey for especially an existing building.
A reinforced concrete building was damaged by the 2016 Kumamoto earthquake. Functional use of the building was not allowed after the earthquake. In this paper, post-earthquake damage evaluation and static non-linear pushover analysis were carried out for the building. In the result, superstructure of the building was classified as moderate damage, however, damage classification of the foundation was heavy due to pile head damage. Furthermore, post-earthquake functional use of the building was discussed.
In this report, a direct estimation method is proposed for non-linear floor response spectrum in RC buildings with a degrading hysteretic loop based on the Takeda model. The method uses the concept of linear modal analysis with empirical coefficients and formulas characterized for the RC buildings. A shift of the resonance region, which is negligible for S buildings with bi-linear hysteresis, is also empirically evaluated for the first mode. Amplification factors of floor responses for the multi story RC buildings are verified by compared with those by nonlinear time history response analyses using number of earthquake input motions.
The mixing proportion of drywall mud tends to be decided by the experience of craftsmen in practice, and it results in the wide property variation. In this study, an experiment was carried out to clarify the influence of the water-mud ratio(W/Md) on the mechanical performance. As a result, the relationship between W/Md and the strength / rigidity showed the strong influence of the W/Md can be only observed when the proportion of sand is small. The equations were proposed to estimate the strength and the elasticity of mud drywall based on these relationships found in the result.
This research discusses what effect it will make when a university (third-party position) joins to a remodeling plan of commercial facilities based on a real case. It has merit to the cooperation in enhancing check function from academic point of view which improves consistency of designs, as well as to the students in providing them with experience of actual planning and a research field. On the other hand, demerit in increasing planning time and planning without high feasibility. Overall, the third-party provided owner with a concrete evidence to pursue its purpose.
Sub Committee on Measurement and Analysis of Environmental Vibration is accumulating building vibrations in wood structure house. When humans sit near the vibration pickup and felt vibration, it affected the measured vibration. In this paper, we describe the change of the vibration characteristics of the building with respect to human influence near the vibration pickup.
Sub Committee on “Measurement and Analysis of Environmental Vibrations” in AIJ, carried out two questionnaire surveys related to measurement, analysis and evaluation of environmental vibrations in buildings. One is abstraction of the important issue and another is understanding of the current status. The surveys targeted for engineers and researchers who had measured building vibrations. From the results obtained by the both surveys, this technical report indicates the issue and current status of measurement, analysis and evaluation of building vibrations. Based on the results, we organize the basic points contributing to a draft of the measurement manual.
A TMD system using a rotating inertial mass damper is proposed to reduce vertical vibration of structural beams and floor slabs subject to walking excitation. The developed TMD is comprised of a ball screw mechanism including flywheels and springs. This system has proved to have significant mass effects because of the ball screw mechanism, even with a small mass of the flywheel. The TMD system was applied to the connecting bridge. The authors carried out the vibration measurement of the connecting bridge and ascertained the efficacy of the newly developed TMD system.
Thermal conductivity of ALC panels is described as 0.19 W/(m･K) in JIS A 5416_2016 which is used for a standard value for JIS certification. On the other hand, 0.17 W/(m･K) is generally used for the design value of ALC panels. In this paper, the design value is examined by measurements of actual ALC under various conditions. The results show that the value is appropriate to use to designing.
This study developed the coupled analysis of heat balance and airflow by combining 3D-CAD based heat balance tool, developed by authors, with CFD, for the purpose of reproducing the distribution of air flow (wind velocity, air temperature) and surface temperature, in order to evaluate the influence of complicated spatial structures upon outdoor thermal environment in urban areas. The 3D-CAD based heat balance tool could calculate detailed distribution of surface temperature in consideration of airflow distribution. In this method, the output condition of one simulation model of each in 24 hours is made as the input condition of the other model until the calculation converges with sufficient precision. The validity of simulation was evaluated with the case study on outdoor thermal environment in the high-rise and dense traditional city in desert.
Wastewater from foods containing high-FOG is generally treated using a DAF method alone or a DAF and activated sludge method. However, these methods are often associated with problems related to operation, management, and cost. Research and development of a new, practical treatment method is needed. This study aims to develop an enzyme lipase biofilm method EBM to replace DAF, DAF + activated sludge by combining EBM for treating wastewater from high-FOG foods. We evaluated the practical implementation of the EBM by running the system on a long-term basis at a facility for treating wastewater from high-FOG foods.
There are few reports about PEFC’s(Polymer Electrolyte Fuel Cell) energy saving performance in the actual house by measured data. In this paper, performance of 18 household’s PEFCs are clarified by using the HEMSs of Teriha smart town in Fukuoka Island City.
The ecological environmental technique was tried on the 2 story complex building, named “Sustainable Energy Hut” that was built lately at Syowa Station, Antarctica. Air-based solar heating system was applied on the building. The computational fluid dynamics is tried on the indoor thermal environment of the building. Good agreement was found with the field measurement of the indoor temperature and the numerical analysis.
Air temperatures in agriculture greenhouses may become too high in summer season for cultivating some plants. So we investigated the effects on tomato plant yield of a groundwater cooling system for the inhibition of temperature rise under high temperature conditions in a tomato cultivation plastic house. The tests were carried out from June to August 2016, in the site of Ishikawa Prefectural Agricultural Experiment Station. The air temperature and OT (Operative Temperature) were reduced and a remarkable cooling effect was acquired with the groundwater cooling system. However, the subject remained about saturation deficit condition.
In the research on Bungalow, a development of British colonial houses, as a Leisure Cottage in Sea Resort, England, the investing process included preliminary documents research, and locally conducted research by the means of site measurement of existing houses and interviews to its current owner and the heritage trust. The research found three key aspects; 1) Established to be fit for a purpose of recuperation in a sea resort, 2) First area-developed with the idea of Bungalow, simplified façade and construction system which later prefabricated, 3) Relationship with art movement in the Victorian era.
This study was examined in order to search the effect of accent wall and wooden floor on the impression and apparent size of living room. The impression evaluation experiment were conducted by using the scale model of living room. Impression of living room is comprehensively improved with yellow or white wall color. The apparent size has the possibility to attenuate the advancing effect of wall coloring by narrowing the width of the wooden floor.
This is a project report of construction of two experimental housing units “hybrid houses”, aiming to discuss the challenges and opportunities to develop earthquake resilient housing in Nepal by introducing Japanese two-by-four construction to Nepalese houses. This paper firstly overviews the characteristics of vernacular houses in Nepal and observes the housing damage after 2015 Nepal Earthquake, mainly through the field visit and interview in June 2015. Then, introducing the architectural characteristics of the hybrid house, the seismic assessment is conducted to convince the safety for earthquakes and winds. The conclusion highlights the lessons learned from the project.
The purpose of this study is to clarify the effect with the change of the common space and management policy in the medical institution for disabled children. For this objective, the institution ahead of rebuilding was surveyed by means of observations of behavior. Some results show as follows : (1)By a change of common space and management policy, an unspecified number of staff came to watch an unspecified number of children. (2)In Day-room where the stay of the staff increased, the posture of the staff calmed down. (3)The diversification of the posture was seen in the slightly disabled children, but was not seen in the severely disabled children. (4)From a result of questionnaire survey, easiness of watching and concerning to the children was a positive evaluation, but the burdens on the watch and assistance of the staff were increasing.