For the purpose of establishing a safety design, a method of calculation for average strain and curvature of composite panels are proposed for evaluation of differential movements herein. A result of calculating about average strain, curvature and shear stress with actual specifications, relation to thickness of components and dying shrinkage become apparent in various geometries of composite panels which are ceramic tiles and cementitious materials produced by extrusion moulding.
For the purpose of evaluating critical differential movements between cement mortars and concrete bodies, material thickness of mortar finishings bonded on concrete were experimented herein. As a result, regardless of the thickness, cement mortar finishings were exfoliated by interface fracture. The exfoliation point are clarified between strains of concrete and finishings. Furthermore critical movements were evaluated on addition of potential performance to deformation of finishings.
Assessment of strength in structure of high-strength, moderate-heat cement concrete was studied using an imitated adiabatic curing specimen. Strengths of the high-strength moderate-heat cement concrete placed in a full-scale model column specimen and that of the imitated adiabatic curing specimen subjected to the same temperature history as that of the full-scale model column specimen were compared. It may be possible that the testing of compressive strength of the imitated adiabtic curing specimen can determine the strength correction value S without testing the strength of concrete in structure.
This paper deals with a trial construction of the newly developed reinforced masonry buildings, which are assembled by utilizing new types of masonry units, a bonding system and casting joint methods. This construction system was originally developed under a comprehensive international project between Japan and USA in order to actualize a high performance of aseismicity, durability and waterproofness in masonry structures. Fundamentals of construction processes, structural details and new devices for composing the various parts in this type of residential buildings developed in the research project are introduced herein.
One of the major concerns of High-strength concrete is its fire resistance. In some of our earlier high-rise RC projects, the most straight-forward measurewas taken to avoid the fire concerns : to provide additional finishing with normal-strength mortar layers all over the column surface. On the other hand, it has been known that the inclusion of polypropylene fibers improves the fire resistance of high-strength concrete by creating a pore structure that enables steam to dissipate. In this report, workability, compressive strength, durability, and fire resistance of the fiber concrete are summarized, and the application of such a concrete to an actual building construction is introduced.
RCFT columns (Reinforced Concrete Columns Formed in Steel Tubes) were used for the first time as the core columns of a 30 story high-rise hotel building. RCFT columns are high strength concrete columns contained in a thin-walled steel tube. The concrete is reinforced by high strength steel bars as the main reinforcement and deformed PC steel bars as shear reinforcement. This type of columns show excellent structural performance and fire resistance. Several factors need to be considered in the erection of such columns. These include, assembling and anchoring of the steel reinforcement within the tube, joining of reinforcement, erection of the steel frames, method of filling the steel tube with 80N/mm^2 high strength concrete and its quality control. These problems were investigated and solved through model tests and during the actual erection.
An approximate analytical solution on wind resistance performance forst anding seam roof construction, which is made of 0.6mm thick fluorine contained resin plate, is developed by using the method of applying a catenary on the curved line representing floating up height of roof construction due to wind pressure. From comparison between the test result of wind resistance and that of finite element method for verification on the above solution, it is confirmed that the solution can provide estimated values on the displacement of roofing materials due to wind pressure with high accuracy. The value from the solution sufficiently coincides with the value tested particularly within the range of wind pressure from 2,000N/m^2 to 5,000N/m^2. Therefore, it has been confirmed that this method is effective for the analytical solution for wind resistance of standing seam roof of 0.6mm thick fluorine contained resin plate.
This paper describes the development of waterproofing sheet with high venting ability (GFL sheet). GFL sheet has sufficient venting abilities to allow the water in concrete slabs to escape as vapor, and it is as durable as PVC waterproofing sheet. First, waterproofing and venting abilities of GFL sheet were measured. Then, the relation between venting abilities and blistering of GFL sheet was examined. Third, durability tests of GFL sheet were carried out, and the durability of GFL sheet was confirmed. Finally, GFL sheet was tried for waterproofing of the roofs of some real buildings.
Two types of the measuring method of water content in fresh concrete were tested in the laboratory and the field. Accuracy of microwave method was examined by comparing with that of the measuring apparent mass in water method. It became clear that water content in fresh concrete can be measured precisely with the microwave method if correction value with water cement ratio is get through the preliminary test.
New method of evaluating the compressive strength of high-strength concrete in structures using BOSS, Broken off Specimens by Splitting Method, was developed. Applicability of BOSS specimen was examined by comparing the compressive strength of specimens taken from a model structure by coring and by BOSS. Effects of water-cement ratio and the sampling height on compressive strength were studied with the variance analysis. It was confirmed that high correlation was found between compressive strengths of BOSS and those of core. Therefore the BOSS strength may be applicable to the prediction of compressive strength of concrete in structures represented by the core strength making use of the proposed formula.
The wind pressure coefficients on the surfaces of balconied middle-rise buildings measured in wind tunnel are discussed in this paper. Mean wind pressures are affected by the characteristics of the approach flow slightly, however, the vale of fluctuating wind pressure is almost in proportion to the turbulence intensity vale of approach flow at the height of the building. The pressure reduction effects to minimum mean and peak pressures due to balconies are found.
This report presents a new hysteresis model of laminated rubber bearings for base isolated structures. Conventional models presented by manufacturers are not verified their propriety on estimating superstructures. Essential components of the new model are classified as follows. Non-linearity of second tangent stiffness is also highly significant as dependency of skeleton curve on strain. Unloading curve shape and variance of yielding load are significant. Hysteresis characteristics of lead-plugged rubber bearings (LRB) and highdamping rubber bearings (HDR) are idealized through assembling regression formulas. The new model is superior in expression of both variances caused by conditions of bearings and unloading curve shape.
This paper presents the experimental results of ultimate deformation capacity and energy dissipation capacity of lead rubber bearings. The lead rubber bearing absorbs the energy in lead plug (circular rod) inserted center. The effect of the interaction of lead plug and laminated rubber bearing has not sufficiently been clarified. Using the two type specimens : test specimen including the lead plug and without lead plug, the ultimate performance of lead rubber bearing is confirmed. Based on the results of compressive shearing tests, the effect of lead plug on the characteristics of lead rubber bearing under the high compressive stress were clarified.
Maximum displacement response of 1 DOF system subjected to 1 cycle sine wave is calculated in order to estimate the maximum displacement response of structures in any earthquake. As results, the maximum velocity responses of linear system based on this proposed method have the constant maximum velocity. The period of sin wave that makes the structure most deformed is 0.85 times of the natural period of that structure. The estimated maximum displacement response displacement is less than 1.5 times of the displacement based on this proposed method.
The purpose of this paper is to clarify the rigid zone lengths for footing beams. The rigid zone lengths were calculated from the results of finite element analyses of footing beams. The equations to estimate the rigid zone lengths were derived to utilize those rigid zone lengths. The estimated rigid zone lengths were applied to the 3-spans 5-stories and 9-stories reinforced concrete frame, and those frames were analyzed by stiffness method. The results of the analyses were in very good agreement with the results of finite element analyses of those frames.
Program LAP3D was developed in order to predict the elasto-plastic responses and collapse behavior of space framed structures by the present authors and their colleagues, using the hybrid stress beam-column finite elements based on Timoshenko's beam-column theory, which yield no discretizing errors in their elastic and elasto-plastic responses of the element. In this paper, the concept of development and outline of LAP3D computer analysis system are described with input data menu. Also, several analytical results using LAP3D are shown and verify that LAP3D has excellent capacity to simulate simply and accurately the more complicate behavior of framed structures.
The authors proposed the relationships between the coefficient of lateral subgrade reaction or the ultimate lateral resistance and the effective stresses based on the results of the lateral laod tests on model piles in sand. For a pile foundation in layers with various ideal effective stresses caused by an earthquake, its lateral behaviors were calculated by the proposed theory in which the above relationships were considered. Furthermore, the piles really damaged by the Hyogoken-Nambu earthquake were also calculated. It is found out from these results that the proposed theory is well able to predict the damages in the piles.
After ten-year service time a tension-truss dome was devoted to a series of full-scale tests. Static and dynamic behavior of the tension-truss frame was examined as well as the structural behavior of the partial reinforcement system with hybrid truss elements. The results of the loading test and pretension measurement are reported here as part 1. Characteristic behavior of the tension truss system with pretension effect was observed. The final failure state was brought about by buckling of a compression truss member. Comparison between designed prestress level and measured prestress is also shown.
The authors have proposed a damping system composed of visco-elastic material and spring, which is invented as a device for hybrid tension structures with small damping. In this paper, the proposed system is applied to front stays for suppressing vibration of the cantilevered football staduim roof tensioned with counteracting back stays. Vibration tests were carried out and compared with the theoretical values, proving the effectiveness of the system.
In 1998 Takiguchi et al. reported the interesting test results of the R/C columns. They gave large deformation to the columns until the columns lay down on the basement. We evaluated the test results and proposed the force-deformation relation model presenting stiffness degrading and bearing force degrading, for ductile R/C columns based on the test results. And we discussed the behavior of basic building models in large deformation under severe earthquake, by using extended distinct element method with the proposed model.
In this paper, we invesigate. the effects of the vibrational characteristics of partition walls on the void slab. The vibration tests were carried out for the void slabs of three apartment houses in Hiroshima city. The experimental values were compared with the analytical values. And the vibration testing with stud supports was carried out for the other building under construction. As the result, natural frequencies of void slabs are raised by the partition walls.
2001.3.24 Geiyo earthquake hit at Chugoku district, fortunately the extensive damage and economic losses did not occur though horizontal accelerations of 1g or greater were recorded at some sites. Concerning reinforced concrete buildings, a couple of low rise buildings were damaged. Two school buildings located at the same site in Hiroshima Prefecture, approximately 26km north of the epicenter, were damaged. One of them was severely damaged and another was moderately damaged while they had almost same structural systems. Objective of this study is to clarify the seismic performance of the existing RC buildings as those damaged buildings. Observed damage levels were compared with results of seismic evaluation method and nonlinear static analysis taking account of concrete strength. It was pointed that the obtained concrete strength which were nearly half of the design concrete strength aggravated damages of the buildings.
Low cycle fatigue tests and dynamic loading tests using several seismic response wave were carried out for the un-bonded brace damper that consists channel steel restraining its buckling. The result indicated that low cycle fatigue characteristics of this damper can be evaluated by Manson-Coffin equation and cumulative fatigue damage level that is evaluated by design curve proposed in the tests with Miner's rule was almost 1. As a result proposed design fatigue curve and evaluation method based on low cycle fatigue characteristics are considered reasonable for the damage level evaluation in seismic response.
Along with the revision of the Building Standard Law, the limit strength calculation was introduced as a new method of verifying the safety of structures against earthquakes. In this paper, evaluation method for earthquake response of buildings with hysteretic damper using the response spectrum method by equivalent single-degree-of-freedom model based on limit strength calculation was examined. As a result, in case that the equivalent viscous damping is appropriately evaluated, the maximum displacement response can be predicted by the response spectrum method using proposed evaluation method of equivalent viscous damping.
The composite structure composed of steel soldier beam, that is usually temporary member, in earth retaining wall and exterior basement R/C wall has been developed. In this study, two types of flexure-shear test of composite basement wall were conducted. The purpose of first test is to clarify influence of external load acting directly to R/C wall, that of second test is to verify the proposed design method. This paper presented the outline of that test, the difference of flexural capacity of composite underground wall depending on loading condition, and the effectiveness of the proposed design method.
Concrete filled steel tubular (CFT) columns have become popular as structural member used for buildings, moreover, a large number of beam-column specimens have been tested. CFT structures are designed by either of the two standards, now. The superposed strength method is basically adopted for the design formulas in both of these standards, only considering the equilibrium of force. However, the lateral force-thrust-rotation angle relationships are not clear. Therefore, in this study, the structural performance of CFT columns have been examined based on the review of existing studies. As a result, the yield strength, the ultimate strength and the lateral force-thrust-rotation angle relationships of the CFT beam-columns have been clarified based on the existing studies.
In cold region, it is considered that dynamic performance of base-isolated buildings is significantly affected by thermal dependence of restoring force characteristics of isolating devices. However, there is not enough of basic data concerned with the thermal condition for designing base-isolated buildings. In this study, thermal environment of isolating devices is investigated by thermal observation in two base-isolated buildings. For improving thermal environment of isolating devices, results of observation suggest that it is effective to enclose them by thermally insulating materials. It is also suggested that the temperature of isolating devices is mainly affected not by outer thermal environment but by the temperature of upper and lower-side structure.
In order to clarify potential fire safety capabilities of Japanese traditional post and beam wooden construction, loaded fire resistance tests have been carried out on two kinds of reinforced soil wall construction in filled in timber frame with and without horizontal deformation simulating an effect of strong earthquake. The test results suggest high feasibility of traditional timber frame reinforced soil wall construction to urban buildings. This indicates an encouraging prospect for the rational fire safety assessment of historic buildings and further development of fire-safe-traditional constructions for the restoration of historic buildings.
Fire resistance test with loading was carried out to get the load carrying capacity of concrete-filled steel tubular long columns without fire protection in fire. The ratio of diameter to length of CFT columns is 12.0. The survey for the demand of CFT long columns in tall building was made. Before fire resistance test of specimen, loading method in tests, and analyses of CFT columns-Steel beam frame in fire were conducted to design specimen. As the results, the regression curves offire resistant time to axial load for circular and rectangular long CFT columns in ISO fire for fire resistant design can be obtained, respectively.
A series of fire resistance tests, which aims at grasping collapse mechanism of the member exposed to fire and accumulating fire resistance test data for aluminum alloy structure, was carried out in this study. Through this study, analytical expressions have been developed to calculate the temperature rise of unprotected and protected aluminum members during fire. Also, an evaluation method of ultimate temperature for structural members was proposed. The Results of the calculations by these methods were found to be in a good agreement with the experimental results.
Strategy for the fire safety design of modern historic buildings is discussed through a case study on the Japan Industrial Club Building restoration project. The spectacular stairwell and lobby on its lower levels are preserved as it was by using the stairwell as the smoke reservoir rather than an evacuation route. Need of further improvement of the performance oriented Japanese Standard Law is pointed out for the promotion of the preservation of modern historic buildings consistent with fire safety requirements in high rise public buildings.
In order to improve the floor impact sound level of the standard rectangular void slab which is 5〜10dB higher at 1kHz band compared to that of ordinary RC slabs, we made several series of experiments. By experimenting light floor impact sound and impedance on the various types of void slab samples, we found that the ones with upper and lower shells fixed tightly were the best against the light floor impact sound and that considerable improvement on the rise of sound pressure at 1kHz. Then, we examined the effect on one of them by measuring the sound transmission loss, and as a result, this improved void slab got better result than 200mmRC slab.
In this paper, the measurement method of the relation to the quality housing securing law was examined. First, impedance of impact time was examined by impulse hammer and bang machine. The result of bang machine was compared with that of the impulse hammer. The result of the impulse hammer corresponded to the calculation value. Impedance in impact time by a bang machine differs about 2-4dB against the calculation value. It was shown that the natural frequency influenced the impedance of the impact time.
The purpose of this survey is to know the actual conditions during the summer of the residential indoor environment in urban area in China. The apartment houses under investigation were sited in urban area of Shanghai, Hong Kong and Xi'an. The questionnaire survey and the measurement of indoor temperature and humidity were done in the summer of 1998 for Shanghai and 2001 for Hong Kong and Xi'an. The questionnaire survey revealed the life style of summer season and the way of use of air-conditioner. The measurement showed that indoor temperature and humidity in Hong Kong and Shanghai are very high. In comparison with these two cities, indoor environment was not so severe in Xi'an.
Indoor air pollution by chemical substances from construction materials has caused health hazard. Bake-out is one of indoor air pollution measures. However, there is a case which bake-out is not effective on reduction of chemical substances emission from construction materials. The aim of this study is to clarify an effective range of chemical concentration in indoor air for bake-out. We experimented with actual residences. On the actual residences, in case of over 1700μg/m^3 TVOC concentration, it was reduced about 30% by bake-out. On the other hand, in case of under 80μg/m^3, it was reduced about 10%. Moreover, HCHO concentration was reduced 20% even under 30ppb.
This paper presents the performance measurement & evaluation for a thermal storage system to use a building slab and others in the classroom of a university building. Ice storage system is popular for use of heat pump system recently. But ice storage tank capacity is a little to use a heating water storage enough. Then this thermal storage system to use a building slab is developed conveniently for increases of heating storage capacity add to heating water storage system. The measurement result indicates the effect of the heating storage system to use a building slab.
The field observation shows that the leaf surface of the vegetation top iscooled to the lowest temperature in the vegetation by the sky radiation, while the air temperature inside the vegetation stays warmer during the clear night. The leaf surface of the vegetation top is refrigerated by the sky radiation, then the air next to the vegetation top is got cooled by the sensible heat exchange from the air to the leaf surfaces. Because of the observation errors on the leaf surface temperature, the calculated results have not completely agreed with the field experiments. The calculation results shows that the atmospheric air is easily got cooled if the leaf area index is large in the tall tree crowns.
In this paper, the effects of wind flow from rivers on outdoor thermal environment in the site for apartment houses, which locates near rivers, were investigated. First, a CFD analysis was carried out for day-time in summer. Then, a CFD analysis for the situation where one river was covered by asphalt was also carried out. Furthermore, suitable building layout for leading the wind from rivers to the targeted site was discussed based on CFD results. With the modified layout, the results showed significant improvement of outdoor thermal environment. It is shown that CFD can be a very useful tool for outdoor environment design.
In this paper, we have investigated the airtight, ventilation performance and VOC concentration of two model houses produced by Ojima laboratory in comparison with the findings of recent detached houses. The model houses were planned for low environment impact and resources circulation. The results indicate that progress of the reuse and recycle rate of the building materials contribute to improvement of the indoor air quality.
The physical features, life styles and living space of residents in 19 nursing homes for the elderly and 18 health care facilities in Niigata prefecture were investigated by means of questionnaire and reports of residents' thermal sensations. The actual conditions of thermal environment in the residents' room was clarified by the measurement in one nursing home for the elderly. The following results were obtained. 1) The metabolic rate of residents in their room is 1met. 2) The height of living space of residents is from floor to 1.1m height including a measuring point at about 0.6m high. 3) The vertical distribution of room air temperature is not obviously shown in summer, and vertical and horizontal distributions were respectively different in heating methods. 4) The globe temperatures varies with room's direction and shading conditions from sunshine. 5) The room humidity causes infections of cold and influenza, and skin trouble in summer and winter.
This paper aims at studying the state of a future dwelling which considered nursing at home and community. It made clear the aged's consciousness and evaluation to the side of the street in houses. As a result of evaluating the present house plan based on conditions required for people, it turned out to be good for the aged that there is the living place by the side of a street in houses, in community and nursing at home.
A purpose of this paper is to make clear the characteristic and the trend of life style of northern region in China. From the point of cleanliness, we focus onto usage of GASHITSU, an equipment of kitchen and a situation of taking on-off shoes. The traditional feeling of cleanliness is observed on urban apartment house. However, the current component of apartment unit spaces is not corresponding to traditional feeling of cleanliness. To consider the hierarchy of cleanliness and the traditional feeling of cleanliness is need to urban apartment house unit planning at northern region in China.
This study is positioned as one of the life style researches of northern region. We researched the houses in urban area of Dalian and Haerbin which are the cities of northeast China. And we clarified the following things by this research. 1. Plan type differs greatly in dwelling units of the same scale. 2. Residents give priority to a drawing room and a master bedroom, and they tend to separate the place for a meal from them. 3. Residents tend to enjoy each other's company on the bed of the master bedroom. Such style of life which uses space for multiple purposes can be employed in a future housing plan of northern region.