We conducted a stirring and mixing test of a cement-based pile-type ground reinforcement method with addition of electric furnace reduction slag on soft ground, which is intended for humus soil. As a result, in the humus soil, (1) the electric furnace reduction slag (S) is 200 kg/m3, the blade cutting frequency is 800 times/m, and (3) the solidification material slurry injection rate is 46.5%. It was found to be 340 kN/m2 or more.

Based on a case study of building structures in operation for over 40 years and had been monitored for 6 years for structural deformation, a method for analyzing length changes of concrete structures in relation to temperature and relative humidity was discussed. The residuals obtained by regression analysis of the length change rate on temperature and regression analysis of the residuals obtained on humidity indicate the possibility of confirming factors other than temperature and relative humidity, i.e., expansion over time, including ASR expansion.

The purpose of this study is to clarify the current status and issues of recycling of finishing material waste derived from production process, construction work and demolition work. The survey was conducted by sending questionnaires to manufacturer associations of the finishing materials. The survey was carried out from July 2021 to March 2022, and the current situations, the future prospects and problem were identified.

In this study, a method was developed to assess the results of bond strength tests with the aim of mitigating the degradation of long-term performance in post-installed anchors. This degradation can occur due to the absence of an upper limit on maximum displacement at bond strength and the allowance for significant creep deformation. The study confirmed that utilizing a judgment equation based on linear approximation and tri-linear curves can evaluate the test results that are allowed, necessary to reassess, potentially suitable for use, and requiring disposal.

In previous studies, dam-break tests and computational fluid dynamics have conducted to clarify the characteristics of tsunami loads acting on the building structure with upstream obstruction. However, the Froude number in the dam-break tests are changed from time to time. It is found that the drag force acting on a structure in subcritical flow is affected by the Froude number. For simplicity, this study focuses on the drag force on building structure with upstream obstruction in subcritical flow where the Froude number is uniform.

Uplift load tests were carried out using two types of unit test specimens that reproduced timber roof frame. From the test using the unit test specimen of the rafter joint, it was confirmed that the method based on the simple beam model in the usual design gives the same result as this result. From the test using unit test specimens that reflect the part of roof frame, the authors tried to understand the damage process progress of the entire roof frame and to calculate the strength of the roof frame, and then compared it with the wind load.

In recent years, strong typhoons have caused significant wind damage to low-rise buildings. The Building Research Institute installed a full-scale dynamic wind pressure loading device. This device is capable of simulating not only static or sinusoidal wind loading but also dynamic wind loading. The present paper describes the basic performance of this new device, particularly focusing on dynamic wind loading. It is expected that this device will expand the scope of testing and research for developing the wind-resistant performance of new and existing exterior materials.

An index that indicates the intensity of seismic ground motion that is highly correlated with the maximum sliding displacement of a sliding foundation was searched. Using not only the seismic intensity, maximum acceleration and velocity, and spectral intensity that are the indices of magnitude of seismic motion but also the effective velocity and proposed index, the correlation coefficients between these indices and maximum sliding displacement of the foundation subjected to seismic motion over 6+ JMA seismic intensity observed in Japan were calculated. Consequently, the correlation coefficient was noted to be the largest for proposed index.

In this study, the authors conducted a microtremor measurement on 15 three-story steel-frame houses and investigated their natural frequencies and damping ratios. Additionally, the authors propose a new method for estimating the natural frequencies of steel-frame houses at the newly constructed state. The proposed method is an evaluation method that does not require modeling based on structural design process, and the validity of the estimated natural frequency which was obtained using this method was verified.

This paper discusses the seismic torsional response of buildings constructed on the ground including the area where the existing piles have been removed. The eccentric ratios of horizontal stiffness of piles are confirmed by assuming some patterns of the pile arrangement and the stiffness reduction. The superstructure is modeled as a uniform shear-beam, whereas the substructure’s horizontal stiffness is modeled as sway springs with eccentricity. Based on the results of eigenvalue analysis and response spectrum analysis, it is shown that the effect of substructure’s stiffness eccentricity on story drifts of superstructure is not so significant.

This paper analyzes the results of a subject experiment designed to evaluate anxiety about simple harmonic vibrations. We examined the correlation between biological reactions and anxiety levels when subjects experienced simple harmonic vibrations by measuring questionnaires and biological reactions and analyzing the correlation between them. The results of a subject experiment using EEG and ECG showed no correlation between EEG indices and questionnaires, but there was a correlation between ECG indices and questionnaires. We found that there is a correlation between ECG indices and anxiety levels.

In recent years, research has been conducted to establish a method for quickly and appropriately determining damage to buildings during an earthquake using sensors, and it’s useful to appropriately evaluate the maximum and residual displacement during an earthquake. The purpose of this study is to propose a disaster assessment method using a satellite positioning system that directly measures the response displacement of a building from satellite positioning information. In this paper, the positioning accuracy is verified when calculating the relative displacement using two movable vibration tables that assume the top floor of a building and the ground surface under earthquake.

The end load-settlement relationship of piles with asymmetric bottom expansion was investigated by centrifugal model tests and three-dimensional FEM simulation analysis. In the centrifugal model tests, the pile end load-settlement relationship was equivalent to symmetrically expanded piles, even under conditions where the pile shaft was located at the edge of the expanded bottom. Simulation analysis also showed that the vertical stress distributions under the expanded bottom surface were equivalent for symmetrically and asymmetrically expanded piles up to the ultimate bearing capacity, and that there was no significant difference in settlement, confirming the experimental results.

We carried out full-scale pull-out loading tests for resistance of cast-in-place concrete belled pile. Tests were conducted with six piles using the soil type of bell enlargement and tilt angle as parameters. Then, simulation analysis of the tests was performed by FEM with a two-dimensional axisymmetric model. The results of the tests conducted in this study could be simulated to some extent by the model which considers the nonlinear characteristics of the pile and the ground. In addition, the basic tendency of the distribution of deformation and shear stress of the ground near the bell enlargement was also confirmed.

This research aimed to establish a method for calculating the compression strength of full-culm bamboo columns. We conducted buckling tests and numerical analyses using small-scale specimens of Phyllostachys edulis, Phyllostachys bambusoides, and compared them. The buckling load of full-culm bamboo columns can be estimated with sufficient accuracy through FEM linear buckling analysis, by appropriately evaluating the culm geometry and the bending Young’s modulus. However, for both species, the bending Young’s modulus is thought to be affected by factors such as cross-sectional size, moisture content, and specific gravity, suggesting a necessity to formalize the relationships between these physical properties.

The objective of this paper is to optimise the geometry to maximise the stiffness of a single-layer lattice shell structure designed as a large-space structure with free curved surfaces, independent of geometrical formulae, and to create a form that can fully demonstrate the mechanical capabilities of the structure. Specifically, their effectiveness is demonstrated by maximising the stiffness and making the member length uniform using the traction method under the constraints on the member length.

Kerf bending is a method of reducing bending stiffness and facilitating bending by cutting slits or other notches in rigid plane materials. This study focuses on the Kerf bending technique for unidirectional bending and proposes a shape control method for active bending arch structures generated by the movement of supported points to achieve arbitrary target shapes. The effectiveness of this method is verified through some experiments and analytical studies.

The objective of this paper is to verify the effectiveness of Topology optimization for Lattice shell structures using CONLIN method. Firstly, using a basic example, we compare the stiffness with the solution obtained by ESO method and we examine their effectiveness. Next, CONLIN method is used to perform topology optimization for Partial multi-layered lattice shell structures and single-layer lattice shell structures. The stiffness of the optimized structures is compared, and the effectiveness of CONLIN method in generating lattice shell structures that are both safe and economically superior is examined.

In this paper, a bolt-type steel joint system for CLT-steel hybrid buildings is proposed. The proposed connection consists of insertion steel plates and steel bolts with a large diameter that connect two CLT walls to steel beams. Evaluation methods to predict the structural performance of the connection are proposed and validated with component-level one-bolt connection tests. It was found that the methods can be used to predict the structural performance of the connection with good accuracy. The proposed connection can utilize the high strength and stiffness of CLT wall panels while maintaining an acceptable level of ductility.

The calculation method of response and limit strength has been used to evaluate the seismic performance of traditional wooden houses in Kyoto. In this paper, firstly, we compared the characteristics of the four seismic performance diagnosis methods based on calculation method of response and limit strength. Secondly, we evaluated the seismic performance of one standard traditional wooden house in Kyoto by the four methods. Finally, we analyzed the factors that cause differences in the results, focusing on the skeleton curve, response calculation method, and ground amplification ratio.

A push-out test was conducted using specimens connecting cross laminated timber (CLT) and concrete with lag screws, inserted at an angle of 0°–60° in the direction of lag screw bearing tensile forces. The purpose of this test was to examine the effect of the insertion angle of lag screws, which are used as shear connectors in CLT–concrete composite slabs, on shear performance. The results showed that when the insertion angle was increased from 0° to 30°, the stiffness (slip modulus) increased and the yield as well as the maximum and ultimate loads tended to reach their maximum values.

In this paper, the bearing strength, embedment stiffness, joint strength, and joint stiffness are confirmed through experiments on load angles in the fiber direction, perpendicular to the fiber direction, and in the brace direction, and a mechanical model that takes into account load angles applicable to the joint between braces and columns is validated.

In this paper, two experiments were carried out to investigate the structural performance of the steel frame with CLT wall with damping system. In the first experiments, it was shown that sandwiching an aluminum-sprayed plate in bolt friction joints caused the slip of the joint and improved structural toughness. In the second experiments, by improving the details of the bolt joints and drift-pin joints, the initial stiffness was increased. Also, the damping effect was confirmed by comparing the energy absorption.

A strength–ductility type seismic retrofit technique for soft first-story reinforced concrete (RC) buildings via adding wing-walls to the existing RC columns is called thick hybrid wall (THW) technique. In this technique, the additional wing-wall does not require longitudinal, transverse and anchor reinforcements; therefore, its construction is easy and cost-effective. In this study, THW technique was applied to an existing pilotis RC building in Okinawa. The objectives of this study were (1) to compare the advantages of THW and conventional retrofit techniques applied to this pilotis building, and (2) to assess the future retrofitting activities through this study.

Unbonded PCaPC structure has the potential advantage of being able to repair or replace damaged parts or members. Therefore, in this study, previous experiment specimens were repaired and structural performances of the specimens before and after repair were experimentally investigated. From the experiments, there was no significant difference in the structural performance between those specimens, and almost all structural capacity was restored by the repairing methods conducted in this study. The maximum strength evaluation method was also proposed based on a macro model, and the calculations showed reasonable agreement with the experiments.

Higher strength steel makes it possible to reduce the weight of members without changing the cross-sectional shape. To apply high-strength steel to light-gauge steel structures, it is necessary to quantify the strength of screw connections. In this study, single plane shear tests of screw connections using high-strength steel were conducted, and an evaluation formula for the strength of the connections was proposed. It was shown that the evaluation formula was able to properly evaluate the strength of the screw connections.

Generally, a steel beam is assembled with a concrete slab by mechanical shear connectors. Recent efforts on the shear connectors enabled structural engineers to realize stiff and ductile connections. However, their performance is usually assessed by the standard pushout tests; thus, the superiority at the member level is relatively untouched. This research first evaluates the shear stiffness of perfobond shear connectors, which was not quantified in earlier studies. Further, the flexural stiffness of the composite beam is derived, reflecting the interlayer slip. Ultimately, the superiority of respective connectors to stud shear connectors is visualized for future applications for building structures.

In this paper, the experiments were carried out to investigate the bearing strength of H-section columns with wing-plate. It was shown that the experimental values can be evaluated accurately by the previous equations. Then the specimens that a column was embedded in a pile head was used for the investigation into the friction strength and superposed strength. The effective area for friction was grasped by the experiment, and the ultimate friction stress was shown. Also, it was shown that the superposed strength of the experiment tended to be lower than the previously proposed calculated value.

Deep learning is applied to images and point clouds data acquired from specimen simulating ceiling sagging. For deep learning on images, AlexNet’s classification accuracy from transfer learning is 93.4%. Principal component analysis of the point clouds is used to determine the curvature of the point clouds. By setting curvature threshold for classification, correct rate is 96.5%. In deep learning for point clouds, classification accuracy by PointNet is 96.7%.

In this study, an experiment was conducted assuming an infinite ceiling to predict horizontal propagation of ceiling flow in a large flat space. In addition, the applicability of the Alpert, Heskestad and Delichatsios equations, which are prediction equations for the temperature and velocity of ceiling flow, and the large flat space of this experiment was reviewed. As a result, the predicted value and the experimental value are matched in the range of r/H<5, but results of the experimental values are different with calculated values after that.

In this paper, we constructed the storage furniture with tatami with an area of about 7.2m² for the reinforced concrete building and examined floor impact sound insulation performance. As a result, when the storage furniture with tatami was installed, the sound reduction was achieved from Lr-60 to Lr-50 when the car-tire was vibrated and from Lr-55 to Lr-45 when the rubber ball was vibrated, respectively. As described above, this report clarified the feasibility of installing storage furniture with tatami in a real building to prevent heavy-weight floor impact sound.

This study focuses on the condition of light color, which is one of the requirements that make up the comfort of sunlight filtering through foliage, and aims to reproduce it as artificial lighting. With this purpose, we conducted four subjective evaluation experiments in experimental room as office or relaxation room. Subjects evaluated the room’s lighting environment which was composed of type of green filter, size of luminaire, ratio of green and white light and illuminance level on the desk. As a result, we found most preferred combination of those factors as well as the positive response ratio of each condition.

We measured the thermal environment of green walls in one public cultural facility with large-scale green walls. It was found that the temperature of the frame of the greening unit rise as high as almost 45 degrees and the temperature fluctuated above 40°C in the daytime. This indicates that the temperature exceeds the upper limit at which plants can grow normally. After the measurement, we experimented to confirm the possibility of avoiding poor growth of green plants by adding special specifications to the existing greening frame in order to control excessive incident solar radiation.

During the COVID-19 pandemic, we surveyed some classroom environments of three elementary and junior high schools in Sendai. The CO₂ concentrations were maintained much lower than pre-pandemic levels by opening windows; however in two schools, they exceeded 1000 ppm for more than 50% of school hours in January. Since the installation of new ventilation fans in one of the schools, the percentage of CO₂ concentrations exceeding 1000 ppm has been reduced to 8.5%. Because of the ventilation path formed through the hall and increased heating usage, the temperature in that school remained nearly constant.

The study analyzes the thermal environment and energy-saving performance of nearly net-zero energy apartments in Japan during winter by measurement and questionnaire. Results show the average indoor temperatures exceeded 18°C even without air conditioning, due to superior insulation performance. Energy consumption for heating was 58.9% to 62.9% of the national average, and residents perceived their homes as warmer, leading to lower temperature settings of air-conditioner. However, there were several challenges, such as the low ratings by residents of non-heated rooms during winter.

The importance of window design and window treatment operation has increased due to the growing need for energy efficiency in the residential sector. This study focuses on the impact of window design and window treatment operation on energy efficiency and the thermal, lighting, and visual environments. In this paper, after comparing the passive potential of some typical detached house models including a model on a narrow site which is increasing in city area. We demonstrate the effect of window design and window treatment operation using simulation. We also aim to present valuable information for both designers and occupants.

In a greening system in which the rooftop and 4F/3F terraces are connected by water-retentive downspouts, the runoff delay effect and rainwater storage effect on each floor were observed. The effect of delaying the outflow peak was less than 1 hour throughout the period. The storage effect was high on the rooftop and 4F, reducing the storage load on the lower floors. In the model section, the total runoff reduction ratio was 8.77% to 95.50%. In particular, storage on the 4F terrace was considered to be important for reducing the outflow load of the entire greening system.

Open-air ducts convey conditioned air along the surface of an open duct due to the Coanda effect. In nozzle-blown air conditioning, when the heat load is large, the jet flow falls due to the temperature difference, and the flying distance is reduced. Therefore, we attempted to improve the flying distance by installing open-air ducts and studied their application to an office space as a case study using CFD analysis. In the verification experiment, it was confirmed that the installation of an open-air duct improves the thermal environment by increasing the efficiency of air distribution.

This paper analyzes and discusses LCCO₂ of temporary site offices. Based on interview surveys, a representative building model of a temporary on-site office is developed and its LCCO₂ is clarified. Emissions from the operation of temporary field offices in Japan as a whole will be estimated to show how much decarbonization of temporary field offices can contribute to the reduction of domestic construction-derived CO₂ emissions. Furthermore, we will evaluate the LCCO₂ reductions of temporary field offices through multiple decarbonization methods, and clarify whether or not decarbonization over the entire life cycle can be achieved.

In this study, I examined the electricity consumption characteristics of Mie University facilities and assessed the effects of energy-saving measures. The base electric power constituted 72% of the total, similar to other universities. I further evaluated four simple models for electricity demand forecasting. My findings indicate that the multiple regression model utilizing differenced series data achieved the lowest mean absolute percentage error. This model demonstrated stable predictions and showed excellent adaptability to changes in trends in university facility electric demand.

CO₂ emissions from building power consumption are calculated using the same CO₂ emission factor throughout the year. However, with the spread of renewable energy, the actual CO₂ emission factor changes from time to time, and the amount of energy consumption in buildings also fluctuates, making true evaluation difficult with conventional calculation methods. In this research, after calculating the hourly CO₂ emission factor, the CO₂ emissions of non-residential buildings are calculated by region and by building use. The verification revealed that the peak CO₂ emissions of buildings are concentrated in the evening, not in the early afternoon.

The thermally renovation for built houses could contribute to global warming prevention. In this paper the analyzed results of operational and embodied carbon, LCCO₂ evaluation in two detached houses before and after thermally renovation were presented. These houses had different scale of thermal insulation renovation. As a result, CO₂ emissions at the renovated stage were 40% for partial renovation and 70% for whole renovation compared to the newly built stage. It was presented that 10 years for partial renovations and 20 years for whole renovations were taken before the effects of reducing LCCO₂ emissions would appear.

A large proportion of energy consumption in Japan is attributable to houses, and the influence of household appliances is not negligible. We have surveyed actual conditions of appliance usage in recently-built houses in the Kanto region. It was confirmed that appliance usage varied widely depending on residential characteristics. In some houses, electric heaters are used every day for room heating or clothes drying. It indicates the necessity of modification of appliance usage for reducing energy consumption and CO₂ emissions.

Decarbonization in agriculture is needed to achieve a carbon-neutral society. This study proposed a definition of net Zero Energy Greenhouse (ZEG) and net Zero Energy Farm (ZEF). For ZEG, a labelling method based on the balance of annual energy demand and supply during operation is developed. An evaluation method of ZEF was proposed based on the balance of delivered and exported energy between the farm’s site boundary. Additionally, this study developed a calculation method for annual energy consumption and CO₂ emission in a greenhouse or farm for the quantitative evaluation of ZEG and ZEF.

In recent years, there have been movements to consider traditional houses as local resources which are used for revitalizing the region. Traditional houses often do not have sufficient heat insulation performance, so it is necessary to renovate them. However, excessive renovation impairs the design of the traditional houses and loses their cultural values. In this paper, in order to verify renovation methods that secure the environmental performance while maintaining the design and cultural value, we analyze the thermal environment such as the skin heat performance and the heating load of traditional houses at Maezawa village in Fukushima prefecture.

Architectural greening has become so ubiquitous that its limitations tend to be obscured. Roofs and walls are not necessarily as suitable for planting as grounds, and they increase the structural load and drains for buildings. As opposed to the typical greening with soil, sponge, felt, this research examines the potential usage of a culture medium grown upon 3D printed resin structures. The structures maintain the water and plants, while variegating the environment and facilitating the maintenance. The research proposes such a system by evaluating the soil moisture tension for the potential usage of both 3D printed structure and soil.

This study aims to analyze the process of residents’ resettlement and the perceptions of the town hall by action research on public housing relocation project in Kamishihoro, Hokkaido. Through interview surveys with the residents and the project staff, the following were found; 1) The staff tends to prioritize resident’s preference over the project road map. 2) Residents who feel pressured to move or who have been assigned where to move may not have enough time to fully consider their resettlement. 3) Residents who leave the process to their families may end up moving without their preferences being reflected.

This paper describes adaptive lifestyle in summer with the retrofitted double-sash windows, blinds attached between the windows in an existing apartment building in Hokkaido. An occupant with retrofitted double-sash windows opened and closed the windows in eight different ways, including opening the exterior windows during the day, using blinds between the windows to shield sunlight, and closing the interior windows whether or not air conditioning is worked. An occupant with unimproved windows opened both exterior and interior windows for ventilation, or closed both windows when the air conditioner was running.

This paper aims to clarify the actual conditions of sharing of storage and goods in cohabitation between parent and child households, and to obtain fundamental knowledge about storage planning that promotes interaction and mutual aid. The sharing of storage and goods is a form of mutual aid in itself. The sharing of goods leads to interaction between the parent and child households, with the sharing of goods as a starting point. When planning a two-family home, in addition to basic zoning, storage areas should be zoned with an eye toward storage and the sharing of items.

The purpose of this paper is to examine the difference in staff opinion between the staff room and the common space in the combined elementary and Junior high schools. The differences were “the number and place of meetings” in the staff room, “dynamic and static use” in the Media Center, and “content of activities” in the multi-purpose room (Learning Space). In the plan for the combined elementary and Junior high schools, it is necessary to plan a space that satisfies the opinions of both sides because these differences of opinion are likely to arise.