Architectural Institute Of Japan Research Articles

Numerical Prediction of Thermal Effect on Flow Field around a High-Rise Building Model

Recently, CFD (Computational Fluid Dynamics) is being more and more used in the investigation of the flow and thermal around high-rise buildings. In this study, prediction of thermal effect on flow pattern around high-rise buildings model located in the surface boundary layer was carried out using k-e turbulence model. Investigation of thermal effect on flow pattern behind the building and comparison between isothermal and non-isothermal building using standard k-e showed that the surface temperature of building wall led to a strong upward motion close to heating wall and decreased the reattachment length behind it. The model sittings of validation study was accomplished by comparing the simulation of wind flow around building models with the experimental data of Architectural Institute of Japan (AIJ) that results showed in weak wind region, standard k-e has good agreement with experimental.

Prediction of Wind Flow around High-Rise Buildings Using RANS Models

Recently, CFD (Computational Fluid Dynamics) is being increasingly used to investigation of the flow around high-rise buildings. In this study, prediction of wind flow around two cases high-rise buildings model placed within the surface boundary layer were carried out using various turbulence models. The accuracy of two-equation turbulence models were compared with experimental data of Architectural Institute of Japan (AIJ).as a result, all two-equation models are shown overestimation the reattachment length behind the buildings.

Estimation of Depth of Concrete Column Members Using Impact Echo Method

In order to maintain the existing concrete structures in a safe and usable state, an overall maintenance management is necessary regarding structure aging from quality management of new construction. Thus, non-destructive testing is needed to estimate the structure damage, defect, or proper construction without damaging the structure. In U.S., there is a standard for non-destructive test (ACI 228.2R-98), and also in Japan, the non-destructive test method and compressive strength estimation manual was prepared by the Architectural Institute of Japan in 1983, and there are active researches in the ground field, but it lacks verification in architecture field. Thus, in this study, a technique that can estimate the depth of concrete column member using the Impact Echo method which is one of the non-destructive test methods shall be reviewed and evaluated for applicability to the architecture field. The specimen was mixed with design strength of 30MPa. The equipment used in testing is Freedom Date Pc Platform Win.TFS 2.5.2 by company Olson of U.S., and the experiment involved leveling the top surface of the concrete member, installing the equipment and applying impact 9 times, and taking the average of the reverberation values obtained. The estimated average depth of concrete column member using Impact Echo method was 304mm for IEC-300, 398mm for IEC-400, and 484mm for IEC-500, and the relative error rate compared to the actual size was 1%~3%. Through this study, the applicability of estimation of depth in concrete column members using impact echo method could be confirmed.

STATISTICAL EVALUATION OF EMBEDMENT EFFECT ON DAMAGE TO BUILDING STRUCTURES BASED ON DATA FROM THE 1995 HYOGOKEN-NANBU EARTHQUAKE

In the 1995 Hyogoken-Nanbu Earthquake, a lot of building structures were severely damaged, and valuable data was compiled after the investigation by the Architectural Institute of Japan (AIJ). This study statistically evaluates effect of embedment due to presence of basements on damage mitigation of reinforced concrete (RC) building structures based on building damage data from the 1995 Hyogoken-Nanbu Earthquake. A multivariate analysis (Hayashi's Quantification II) is used to investigate factors (items) that have a strong effect on the degree of damage to RC buildings. The results indicate that embedment has a remarkable effect on reducing damage; the degree of which is similar to the construction year effect (due to major revision of Japanese building standard law that became effective in 1981). This finding may support further positive adoption of embedment effect in seismic design practice.

日本建築学会「合成構造設計規準」の刊行

合成構造の多様化傾向を鑑み，日本建築学会では，従前の「鉄骨鉄筋コンクリート構造計算規準」を親規準とした構造設計規準体系を改定し，多種多様な合成構造全域を包括する親規準と成る「合成構造設計規準」に基づき，新たな構造設計規準体系を構築した。今回刊行された「合成構造設計規準」は，現状の合成構造に関する構造設計クライテリアや接合部等の共通的な設計規準事項を内容とするとともに，今後開発される合成構造も視野に入れて，新たに開発される合成構造の設計法確立に資する内容も取り込み作成されている。

サステナブルでレジリエントな建築環境をめざした日本建築学会の取り組み

サステナブルでレジリエントな建築環境をめざした日本建築学会の取り組み

Cross Comparisons of CFD Results of Wind and Dispersion Fields for MUST Experiment: Evaluation Exercises by AIJ

In order to apply Computational Fluid Dynamics (CFD) techniques to estimate pollutant dispersion in urban areas, it is important to assess the performance of numerical models used to estimate these phenomena. Recently, the MUST (Mock Urban Setting Test) has often been adopted as a test case for evaluating numerical models for micro-scale urban meteorology. This paper presents the results of model evaluation exercises carried out using MUST based on the Architectural Institute of Japan (AIJ) experience. The results of model evaluation exercises conducted by AIJ are broadly consistent with the results obtained by the COST group. However, the variety of results by each computation can be minimized by setting standard computational conditions. All computations including both RANS and LES show good agreement with wind experiment data. In general, LES cases show comparable accuracy to RANS in predicting U and W. However, LES shows better agreement than RANS in TKE and concentration.

콘크리트 비파괴시험법을 이용한 사방댐 안정도 평가에 관한 연구

This study was conducted to investigate a stability trend within 6 above average and 4 blow average erosion control dams, which were selected by The Korean Association of Soil and Water Conservation and were built in 1990s in Gyeonggi and Gangwon Province. The study was aimed to measure rebound hardness of upstream face, flood way and downstream face from those dams selected by using 'Concrete Test Hammer'. The main purposes of the study are selection of compression strength prediction equation and scope of wavelength, which successfully demonstrate non-destructive test results for erosion control dams. There is an opportunity to increase disaster prevention ability when stability vulnerability of concrete erosion control dam is detected in a timely manner. Results of the compression strength investigation express that there is a consistency with visual inspection of stability that has been processed by The Korean Association of Soil and Water Conservation. We concluded that a prediction equation, which was developed by Architectural Institute of Japan (AIJ), shows highest suitability in Korean erosion control dams when stability investigation is performed. The detailed criteria for the test result are 'stable', 'detail inspection required' and 'poor' for over 300 , 250~300 and below 250 respectively. Standards for stability of Korean erosion control dam and a compression strength prediction equation (that corresponds to the standards of the stability) should be established on the basis of chronological data of erosion control dam compression strength. Systematical approach for stability inspection that carries out remodeling or repair when problem on erosion control structures are detected through visual inspection and simple stability test, is necessary for the future disaster prevention.

ULTIMATE BEARING CAPACITY ANALYSIS OF GROUND AGAINST INCLINED LOAD BY TAKING ACCOUNT OF NONLINEAR PROPERTY OF SHEAR STRENGTH

In the assessment of bearing capacity of footing, the bearing capacity formula proposed by The Architectural Institute of Japan (AIJ) has been widely used in Japan for the design of building foundation. However, this formula is limited to simple conditions like simple footing shape, flat ground and uniform material property. Although the rigid plastic finite element method (RPFEM) can solve this complex problem, it has not taken into account the size effect in assessment of bearing capacity. This study newly develops the RPFEM by introducing the nonlinear shear strength property against the confining stress and proposes the rigid plastic constitutive equation of parabolic yield function, basing on the change in the angle of shear resistance of Toyoura sand. The developed method and the bearing capacity formula (established by empirical approach) provided identical results for various footing sizes showing good estimation for wider range of footing size.

日本建築学会「高強度コンクリート施工指針・同解説」の改定

日本建築学会「高強度コンクリート施工指針・同解説」の改定

東北地方太平洋沖地震等による鉄骨造文教施設鉛直ブレースの震動被害

A reconnaissance of steel school buildings damaged by the 2011 Tohoku earthquake has been conducted by the Architectural Institute of Japan. This paper discusses the various types of seismic damage to vertical braces observed in 129 school buildings. The braces of pre-1982 buildings which were either unretrofitted or not seismically evaluated suffered more damage, compared to either pre-1982 retrofitted or post-1982 buildings. Most of the damage to connections in older buildings are caused by either old design practice, where the connection strength does not exceed the brace strength, or improper construction.

Reinforced concrete beams with web openings: A state of the art review

The construction of modern buildings requires many pipes and ducts in order to accommodate essential services such as air conditioning, electricity, telephone, and computer network. Web openings in concrete beams enable the installation of these services. A number of studies have been conducted with regards to reinforced concrete beams which contain web openings. The present paper aims to compile this state of the art work on the behaviour, analysis and design of Reinforced Concrete (RC) beams with transverse web openings. A variety of aspects will be highlighted and discussed including the classification of openings, guidelines for opening location, and the structural behaviour of RC beams with web openings. Various design approaches will also be detailed, for example the American Concrete Institute (ACI) approach, the Architectural Institute of Japan (AIJ) approach and the strut and tie method. Moreover, the strengthening of RC beams with openings using Fibre Reinforced Polymer (FRP) material and steel plates is presented. Finally, directions for future research based on the gaps which exist in the present work are presented.

DEVELOPING A LCA DATABASE OF WOOD MATERIALS

At present, the use of eco-friendly building materials is needed in order to reduce the environmental load. From this viewpoint, a LCA database has been established by the Architectural Institute of Japan. However, the database has two problems. First, the environmental load of imported wood materials is not evaluated. Second, the environmental load of wood materials in the database is stored as an average value. The purpose of this study is developing a LCA database of wood materials that takes into account imported wood materials and contains detailed data for the forestry, manufacturing, and transport stages.

2011年度日本建築学会大会<br>木質材料の防耐火性に関する発表概要

2011年度日本建築学会大会<br>木質材料の防耐火性に関する発表概要

DEVELOPMENT OF STRUCTURAL ELEMENTS USING ENERGY·CO<sub>2</sub> MINIMUM (ECM) CEMENT·CONCRETE

Cyclic loading tests of two columns and three beam-column subassemblages using currently developing cement, named Energy CO2 Minimum (ECM) cement, were carried out. Galvanized steel wire mesh was used for transverse reinforcement. The test results showed that for all specimen AIJ (Architectural Institute of Japan) criterion value of shear strength was exceeded. Test results also proved that structural elements using ECM cement and galvanized steel wire mesh for transverse reinforcement can be treated the same as using normal cement and normal reinforcement.

The Past, Present and Future of Research on Fuzzy Theory, Soft Computing and Related Areas at Architectural Institute of Japan : Including Some Examples from Shingu Lab., Nihon University(<Special Issue>New Development of SOFT Science in BMFSA2009-AMAMI)

The Past, Present and Future of Research on Fuzzy Theory, Soft Computing and Related Areas at Architectural Institute of Japan : Including Some Examples from Shingu Lab., Nihon University(<Special Issue>New Development of SOFT Science in BMFSA2009-AMAMI)

전단 보강이 없는 FRP RC보의 전단강도 예측

There are many problems in application of FRP reinforcing bars as shear reinforcement, since bending of FRP bars is not a feasible process on construction site. Even though FRP bars can be manufactured in bent shape, they have lower strength at bent location. However, there are no serious problems to use FRP bars as flexural reinforcement. Plates or slabs like bridge decks, in general, do not need shear reinforcements. These types of members with FRP flexural reinforcement have lower shear strength than those with conventional steel flexural reinforcement. However, reliable process or equation for shear strength estimation of FRP reinforced concrete without shear reinforcement are not established, yet. In this study, predicted shear strength obtained from available design equations and assessment equations are compared with 211 experimental results. The results showed that among the current design codes, the Architectural Institute of Japan (AIJ) and the Institution of Structural Engineers (ISE) provided the best estimation. ACI 440.1R-06 provided conservative results with degree of dispersion similar to that of ISE. In addition, regression analysis on the collected experimental results was conducted to develop regression models. As a result, a new reliable shear strength equation was proposed.

EVALUATION OF DAMAGE ON OUT-DOOR FLAT-BOTTOM CYLINDRICAL TANKS IN KASHIWAZAKI-KARIWA NUCLEAR POWER STATION OWNED BY TOKYO ELECTRIC POWER COMPANY

In Niigata-Ken Chuetsuoki Earthquake (July 16, 2007), water storage tanks suffered considerable damage. These tanks belong to C-class facilities. Types of damage were versatile. Some suffered buckling of tank walls such as diamond pattern and elephant-foot bulge type of buckling. Some suffered breaking and permanent elongation on anchor bolts circumferencially distributed at the bottom of tanks, accompanied with uplift of bottom plates.The seismic input recorded at the site was tremendously large compared with that applied at the design stage, however, most of damaged tanks barely escaped from the fatal damage of leakage of water.In this paper, real behaviors of tanks are estimated referring to ‘Design Recommendation for Storage Tanks and Their Supports’ published by Architectural Institute of Japan in 2010.

DEVELOPING A LCA DATABASE OF IMPORTED WOOD MATERIALS

Wood is well-recognized as a renewable resource that can contribute to the reduction of environmental load and it has long been used as a material in the building sector. The LCA database for buildings (established by the Architectural Institute of Japan) has been developed and utilized to evaluate the reduction of environmental load through the use of wood materials. However, this method does not evaluate the environmental load incurred through the production and transportation of imported wood materials, although wood materials are imported into Japan in large volumes. Therefore, this study aims to develop a database which includes the environmental load of imported wood materials from several countries and regions.

Review of Cross-Ventilation Research Papers - from the Working Group for Natural Ventilation and Cross-Ventilation of the Architectural Institute of Japan

A working group for natural ventilation and cross-ventilation at the Architectural Institute of Japan (AIJ) was established in 2005 by researchers and designers with an interest in this topic. One of the tasks of the working group is to review and classify related research papers. This paper introduces the activities of the working group and presents some results of the review work. As examples of the review work, this paper concentrates on the area cross-ventilation rate and the interference coefficient concept of the cross-ventilation phenomenon that solves the problem of the remaining dynamic pressure inside a room.