著者
金子 治 中井 正一
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.79, no.695, pp.83-91, 2014-01-30 (Released:2014-07-10)
参考文献数
23
被引用文献数
3 4

There were several cases reported where buildings had to stop functioning normally because of the damage to foundations during the 2011 Great East Japan earthquake. The authors carried out static analyses using a foundation structure model in order to investigate the cause of damage to pile foundations by focusing on three typical buildings. Lateral load at pile head and differential movement of soils were estimated based on a seismic response analysis by using recorded ground motions of the 2011 Great East Japan earthquake and by looking into the soil profiles and structural characteristics of buildings. Load-deformation characteristics of pile elements and soil springs were formulated so that the model can incorporate nonlinear behaviors. Results obtained from the analysis explain fairly well the actual damage of pile foundations. It was confirmed that a controlling factor causing damage to pile foundations is the existence of soft soils and the variation of surface soil layers. The proposed procedure can be considered as a practical seismic design method of foundations that ensures a required performance for large earthquakes.
著者
在永 末徳 乗政 全成 寺尾 直樹 行平 信義 尾池 哲郎
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.70, no.589, pp.23-28, 2005-03-30 (Released:2017-02-11)
参考文献数
8
被引用文献数
2 2

The casting calcium carbonate, which is made by pressed lime, acquires the compressive strength on two stages. The behaviors of compressive strength of the casting calcium carbonate on these stages are investigated by examining the compressive strength and the rate of water absorption. At the first stage the casting calcium carbonate, in the form of the lime, gets the compressive strength by the cast pressure. We find the compressive strength can be expressed by the equation associated with the rate of water absorption. At the second stage it acquires the compressive strength as the carbonation proceeds. We find the relation between the rate of water absorption and the rate of carbonation is linear. We then conclude the compressive strength of the casting calcium carbonate can be expressed by the rate of carbonation.
著者
松下 哲郎 平尾 宙 丸山 一平 野口 貴文
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.73, no.623, pp.1-8, 2008-01-30 (Released:2008-10-31)
参考文献数
51
被引用文献数
8 2

In this study, Powder X-ray diffraction (XRD)/Rietveld analysis, which has been utilized in recent years as a technique for quantifying the crystal mineral phase of cement and cement paste, was applied to quantify the reaction rate of cement minerals and the proportions of hydration products. Its accuracy and availability was verified by comparing with the following properties, reaction rate of minerals by internal standard methods of XRD quantitative analysis, rate of heat liberation of cement by conduction calorimeter and amount of combined water of cement paste. Experimental factors were three types of cements, three levels of W/C, three levels of mixing/curing temperatures. The results showed that XRD/Rietveld analysis can quantify the hydration rates and products of cement paste with high accuracy.
著者
田中 英之 田村 幸雄 大竹 和夫 中井 政義 金 容 徹
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.77, no.678, pp.1211-1218, 2012-08-30 (Released:2012-10-15)
参考文献数
17
被引用文献数
1 2

Tall buildings have been traditionally designed to be symmetric rectangular, triangular or circular in plan, but recent tall building design has been released from the spell of compulsory symmetric shape design, and free-style design is increasing. One important advantage for this trend is that rather complicated sectional/structural shapes are good with regard to aerodynamic properties for across-wind responses, which is a key issue in tall building wind-resistant design. A series of wind tunnel tests have been carried out to determine wind forces and wind pressures acting on the large number of tall buildings with various configurations. The results of these tests have led to comprehensive understanding of the aerodynamic characteristics of various tall building configurations.
著者
河合 真梨子 福和 伸夫 護 雅史 飛田 潤
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.74, no.636, pp.409-416, 2009-02-28 (Released:2009-11-02)
参考文献数
13
被引用文献数
3

This paper proposes a new place-name classification table considering geographical features and soil characteristics, which helps interpretation of seismic hazard maps. This table is classified into two soil groups (stiff soil and soft soil) based on the origin of their Chinese characters. We select bus-stop name from many kinds of place-name. This reason is the following two points. Distribution density of bus-stop is almost evenly in the city, bus-stop name mostly remain past place-name. The validity of the new place-name classification table and bus-stop name is clarified through case studies on the three major metropolitan areas of Japan.
著者
村上 雅英 田原 賢 藤田 宜紀 三澤 文子
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.61, no.481, pp.71-80, 1996
被引用文献数
10 4

About 2000 wooden structures were surveyed through 81. 6 ha, the seismic intensity was over 7, in Higashi Nada ward in Kobe-city where had been seriously damaged by the Hyogo-ken-Nanbu earthquake on Jan. 17th '95. The problems of the traditional Japanese post and beam wooden structures houses of two stories or less are not only pointed out, but also the cause of mechanism of collapses were determined according to the close investigation of 185 units through the seismic destruction area. It is recognised that quite numbers of the small and narrow houses with dry-wall exterior finish collapsed among many other Japanese traditional wooden structures with mud-wall exterior finish. The primary cause of collapses of these houses was that the structural planning was ignored on their floor planning.
著者
圓 幸史朗 河野 允宏
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.66, no.550, pp.47-55, 2001
参考文献数
35

Stochastic properties of broadband strong motions are investigated using the fractal source model. The model is described by the limited dynamic data reflecting uncertainty and heterogeneity on the fault plane. The soil ground model for source-site path is presented by the theoretical Green's function of the multi-layered half space. The simultaneous simulation test has been tried for the recorded ground motions at some sites in the 1994 Northridge earthquake and the 2000 Western Tottori prefecture earthquake. The average spectra and the duration time of the synthetics correspond well with those of the observed within 20 kilometers from the fault region.
著者
伊藤 洋介 河辺 伸二 大羽 慧
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.82, no.739, pp.1321-1327, 2017 (Released:2017-09-30)
参考文献数
12
被引用文献数
1 1

It is expected that elderly people can't remove snow on their own, and have a trouble going out. There are some ways to remove snow which do not require physical effort, but each conventional way has problems. Therefore, the authors have attempted to invent the “heating mortar block system” to remove snow. In this system, electromagnetic waves are generated by the oscillator, and then irradiated mortar blocks with. A heating mortar block is composed of 3 layers; 1. electromagnetic absorption material 2. base material (without electromagnetic absorption ability) 3. electromagnetic shielding material. Electromagnetic absorption material placed near the surface absorbs electromagnetic waves and converts it into heat. This system uses this heat to melt snow on the blocks. Electromagnetic absorption material is mortar mixed with electric arc furnace oxidizing slag as aggregate (hereinafter, called “the slag mortar”), and base material is a mortar mixed with sand as aggregate (hereinafter, called “the sand mortar”). According to preceding research, there is a correlation between abilities of electromagnetic absorption and heating. But, the characteristics of electromagnetic absorption and heating about electromagnetic absorption material composed of the slag mortar and the sand mortar has not been studied enough. So, the purpose of this study is to clarify these things and develop the base theory to design heating mortar blocks absorbing the electromagnetic waves and heating well. Ability of electromagnetic absorption is evaluated with return loss calculated by S-parameter method. Within the measuring range, following things were clarified. (1) When the sand mortar is superposed under the slag mortar, the thickness of which the sand mortar causes the prominent absorption of electromagnetic waves at specific frequency (hereinafter, called “peak”), has a period. And, it is possible to choose a thickness from some thickness by considering this period. (2) When the sand mortar is superposed under the slag mortar, it is possible to determine the thickness, by specifying the thinnest thickness through the experiment and using the equation produced in this study. (3) It is possible to adjust the temperature rises of the heating mortar block without changing the thickness of the slag mortar which is the electromagnetic absorption material, by just changing the thickness of the sand mortar. (4) When the thickness of sand mortar superposed under the slag mortar is 30mm, 62mm or 93mm and it is irradiated with electromagnetic waves of frequency 2.45GHz, the temperature rises 20.6 °C, 17.3 °C or 19.2 °C each. In these thickness, return loss also rise as a peak. (5) When the sand mortar is superposed under the slag mortar, it is possible to evaluate the heating ability by return loss.
著者
桑村 仁 松本 由香 武谷 政國
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.62, no.494, pp.129-136, 1997-04-30 (Released:2017-02-02)
参考文献数
21
被引用文献数
2 3

It has been pointed out in this decade that the currently used thick cold-formed box-section columns in building frames may fail in the mode of brittle fracture instead of local buckling, and that their ductility preceding brittle fracture may not be enough to resist a severe earthquake. In order to solve this problem, hot-rolled box-columns have been recently developed, in that the forming is done at high temperature to avoid cold working. In this study, the ultimate behaviors of the box-columns having through diaphragms, which is the current practice in building steel construction, were experimentally investigated. It was found that the newly developed hot-rolled box-columns exhibit much higher ductility than the conventional cold-rolled box-columns when the ultimate state is governed by brittle fracture as well as by local buckling.
著者
吉敷 祥一 山田 哲 竹内 徹 鈴木 一弁 岡田 健 和田 章
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.69, no.575, pp.113-120, 2004
被引用文献数
10 5

Many steel structures suffered damage at beam-to-column connections under the Northridge and Hyogo-ken Nanbu Earthquakes more than 8 years ago. After these earthquakes, a remarkable number of studies have been made on beam-to-column connections in U.S. and Japan. Nevertheless, in those studies, little attention has been paid to the point of repairing. The purpose of this study is to propose new ductile steel structure frame system, which realizes not only structural performances but also easy repairing after heavy earthquake. This system is based on bolted connections with split-tee. Main feature of this system is to limit plastic deformation to the splittee at bottom flange. To the contrary, the split-tee at top flange can be kept in elastic, because the center of rotation stays at the top flange of beam end.Consequently, when the structure using this system suffers compulsory deformation under the earthquake, the deformation concentrates on the split-tee at bottom flange. Finally, two series of static tests were conducted. First series are axial loading tests of the weak-web-split-tee elements, and second series are bending tests of beam-to-column connections having weak-web-split-tee. From the result of these tests, we verified that this system had efficient deformation capacity. In addition, the damaged part of this system would.be easy to repair or change to new one.
著者
林 康裕 宮腰 淳一 田村 和夫
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.62, no.502, pp.61-68, 1997
参考文献数
26
被引用文献数
14 5

We have revised the distribution of the peak ground velocities (PGV) in the Hanshin area during the 1995 Hyogo-ken Nanbu earthquake. The original PGV distribution was based on only the damage of residential houses, but the damage of the other types of buildings is also considered in the revision. In addition, we have refined the resolution of PGV in many cho whose area is broad. Evaluated PGV distribution has good correspondence with observed records and evaluated ground motions in the main shock except for the liquefied area like reclaimed land or the cho in which the PGV level drastically changes. On the other hand, the PGV in Nishinomiya city is not less than 60% of that in the Kobe city.
著者
米澤 健次 諏訪 好英 小野 佳之 長沼 一洋
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.71, no.601, pp.151-158, 2006
被引用文献数
1 1

Hydrogen explosion tests were conducted to grasp nonlinear response and to get its fundamental data for reinforced concrete walls subjected to hydrogen explosive load. In the tests, an explosive source (37m^3 -volume) that contained 30% hydrogen and 70% air was detonated, and the responses of the walls close to the source were measured. Two preliminary and three main tests were conducted for a variety of wall types with different thickness, heights, and steel reinforcements. The walls were instrumented with pressure sensors, displacement sensors, strain gauges, accelerometers and thermocouple. Wide varieties of experimental data were obtained in damage ranging from elasticity to complete failure. It was also confirmed that the wall nonlinear response depends on the blast wave duration and initial natural period. With increasing the initial natural period, the higher vibration modes were appeared on the response of the walls. Furthermore effects of strain rate were quantitatively investigated on the basis of the test results.
著者
エスコバール・S ホセ・アルベルト ロペス・バティス オスカル 菅原 まりも
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.63, no.508, pp.93-100, 1998
被引用文献数
9 3

A methodology to locate and assess structural damage in reinforced concrete structures from the known modes and natural frequencies of the structures is presented. The damage is defined as the stiffness loss of the structures. Using the perturbation method, the dynamical characteristic changes and the corresponding structural properties such as the stiffness changes are related so that the damaged floors of a structure are located. With the use of the Baruch and Bar Itzhack equations, the perturbed stiffness matrix is adjusted. Comparing the non-damaged stiffness matrix with the obtained perturbed stiffness matrix, the structural elements' damage is located and assessed. The sensitivity matrix that defines the lateral stiffness' sensitivity to the elemental stiffness changes is introduced.
著者
村尾 修 山崎 文雄
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.67, no.555, pp.185-192, 2002-05-30 (Released:2017-02-04)
参考文献数
16
被引用文献数
15 10

A number of building damage surveys were carried out for different purposes after the 1995 Hyogoken-Nanbu Earthquake. The damage surveys by local governments intended its use for property tax reduction while the survey by the CPIJ & AIJ group aimed to get technical records. This paper presents building fragility curves based on the CPIJ & AIJ damage survey data for Nada Ward, Kobe City, and the detailed building inventory, structural type and construction period, provided by Kobe City Government. This paper also compares them with the fragility curves based on the local government's survey for property tax reduction to clarify the relationship between the two evaluations.
著者
木村 俊明
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.86, no.790, pp.1655-1663, 2021-12-01 (Released:2021-12-01)
参考文献数
24

Since there is a close relationship between the form and force in the large span spatial structures, it needs to design a suitable structural form corresponding to the stress transmission. Furthermore, it is desired to construct efficiently with saving resources for reducing environmental loading. Structural engineers need to judge totally by considering various requirements (e.g. structural safety, aesthetics, constructability, and economics) for a short time. A structural rational form can be found easily using the optimization method. There are various studies of computational form-finding methods for large-span spatial structures. Recently, it has been applied for the realization of practical design. Generally, optimal shape tends to be a complex shape. According to the construction reports of its application, it can be confirmed that issues about constructability of complex shapes and reducing scaffolding material have been solved in the construction phase. It is significant to solve the construction problems during the early design phase by using optimization methods. Removing supports is one of the important construction processes for spatial structures. Generally, it is mentioned that depending on the support conditions during the removal process, the internal stress may be higher than those in the completed state in the RC large-span structures. From a point of view of safety, it is necessary to plan to remove supports carefully. Furthermore, planning for the construction process depends largely on the experience of the contractors/designers. In the case of complex shapes, it can be imagined that it involves a lot of trial and error and is extremely difficult. If the construction plan can be reasonably designed at the stage of the form-finding process, it will be possible to realize further resource-saving and efficiency of construction materials. There are a lot of studies about optimization for removing supports in the construction process of the truss or tensile structures. However, to the author's knowledge, there are a few studies for RC spatial structures. This paper presents a simultaneous optimization method for the large span spatial structures obtaining the process of removing supports in the construction and the shape of the completed state. An optimization problem is formulated to minimize the summation of the strain energy during removing supports. The optimization algorithm consists of two methods. The coordinates of B-spline control points are optimized using Sequential Quadratic Programming (SQP). Furthermore, Local Search (LS) is used for obtaining the order of removing supports. It is shown in the numerical examples that not only obtaining strain energy minimized shape, react force and stress are suppressed during the process of removing through optimization. In the case of a 2D arch, the optimal order is to start from the end with removing the center at last. In the removal phase, it is effective to leave the center support during the removal to reduce bending deformation. By using this method, it can realize the construction plan for the supports considering both structural safety and constructive efficiency. Moreover, the proposed methods require less computational cost than the heuristic method shown in the numerical example. In the optimization using NP2, it is possible to obtain the solution with less computational cost than using NP1. However, the order of removal of supports becomes complicated. From a point of view of practical design, this result needs caution to avoid mistakes in construction.
著者
八木 尚太朗 伊山 潤 福島 佳浩 吉敷 祥一 石田 孝徳 清家 剛 山田 哲
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.86, no.788, pp.1400-1411, 2021-10-30 (Released:2021-10-30)
参考文献数
19

From a viewpoint of continuous use of buildings after an earthquake, it is important to understand the behavior and damage progress of non-structural elements such as dry partition wall under a large deformation owing to earthquake, and to establish a method to monitor the condition of non-structural element in a qualitative manner as well as in a quantitative manner. In this paper, first the past studies on loading experiments for dry partition wall were summarized, showing that enough studies considering the effect of opening and the behavior of walls located away from beam location have not been done. Based on the review of past studies, a full-scale static loading test of steel moment frame with dry partition walls was performed. The specimen has two frames; one frame has a flat wall without opening and the other frame has a wall with a door opening and a corner in the frame. In the latter frame, some part of the wall is placed not directly under the beam. Static cyclic loading was applied, increasing the peak story drift up to as large as 1/33. In the experiment, visual observation was performed at each loading step. Rotation angle and vibration of the walls was also measured using MEMS acceleration sensors. The flat wall had relatively few board cracks and other damage. However, the boards on upper layer in the center part of the wall began to rock at the loading step of a 1/100 story drift. Then at 1/50, the boards showed out-of-plane deformation and when unloading after reaching 1/33, boards fell off. On the other hand, on the wall with the opening, a gap opening between the boards, and a crack on the L-shaped boards at the corner of the opening were observed at a relatively small story drift angle of 1/400. Regarding the wall located away from the beam, damage was concentrated on the wall which was orthogonal to the frame and not under the beam. The wall rotated around the vertical axis, and this was thought to be due to the difference of trackability to the structure between walls. Due to this behavior, a crack at the corner of the wall was seen at the story drift angle of 1/400, and at 1/75 the upper track opened, and studs were seen to come off. The rotation angle and the vibration of the walls were measured by MEMS acceleration sensors. The measurement result corresponded well with the damage observation. It was found from the measurement results that there were signs before damage and behavior of walls could be visually confirmed. Moreover, it was found that the vibration frequency of the damaged wall decreased (period became longer) as the loading progressed. This change may be representing the damage development in the wall. From these observations, it was confirmed that the MEMS acceleration sensor can capture small movement implying damage in partition wall in a quantitative manner, but more study should be necessary about the relationship between the measured deformation and the degree of damage and performance degradation, to utilize accelerometers for structural health monitoring of partition walls.
著者
村上 雅英
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.86, no.785, pp.1068-1073, 2021-07-30 (Released:2021-07-30)
参考文献数
5
被引用文献数
1

The formula for the full plastic nail arrangement modulus Zpxy which is used in the calculation of the ultimate shear capacity of the sheathed shear walls with any nail arrangement was theoretically derived by using the upper bound theorem.The unknown values are the rotation ratio (θx/θy) and the neutral axis positions (xo and yo) in the calculation.The difference between the calculation with the elastic values and the plastic values as unknown values is within 1.5%.
著者
五十子 幸樹 井上 範夫
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.75, no.655, pp.1653-1660, 2010-09-30 (Released:2010-10-20)
参考文献数
9
被引用文献数
3 1

Study on frequency transfer characteristics of a displacement-dependent damper modeled by complex stiffness shows that it has advantage in reduction of base shear and maximum response acceleration of the superstructure of a base-isolated building compared with a conventional velocity-dependent damper such as an oil damper. To realize a displacement-dependent damper, a simple control rule to simulate the complex damping model for active or semi-active dampers is proposed.
著者
早川 崇 片岡 俊一 宮腰 淳一 佐藤 俊明 横田 治彦
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.75, no.650, pp.723-730, 2010-04-30 (Released:2010-06-14)
参考文献数
25

We estimated the fault of the 1924 Tanzawa earthquake (Mj7.3), which was the largest aftershock of the 1923 Kanto earthquake (Ms8.2). We could successfully reproduce the observed waveforms in central of Tokyo based on the estimated fault model. This is very important to investigate the characteristics of ground motions by M7 events occurring in the Tokyo Metropolitan area because we only have a few observed waveforms of such events in central Tokyo. Finally, we calculated ground motions around Tokyo metropolitan area by the estimated fault model. The simulated ground motions do not exceed the design spectra around the area but in west of Kanagawa Pref.
著者
今岡 克也 桜井 秀浩
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.64, no.519, pp.47-54, 1999
被引用文献数
1 1

The 1997 Aichiken-Tobu Earthquake (M5.8) occured in 39 km depth beneath Mikawa region. By questionnaire survey method seismic intensitiy distribution was investigated to about 250 elementary schools in Mikawa region. And microtremor measurement have been carried out at the same schools. The purpose of this study is to interpretate the seismic intensity distribution from microtremor characteristics and souce effects. Seismic intensity increment is defined to be difference of seismic intensity of equivalent hypocentral distance in which source effects are excluded. In conclusion the period of peak horizontal-to-vertical spectral ratio of short-period microtremors is found to be in good agreement with seismic intensity increase. And the average of horizontal-to-vertical amplitude ratio of microtremors is better agreement with seismic intensity increase.