Yahagi Construction Co.

Japan

Yahagi Construction Co.

Japan

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Kamiya T.,Yahagi Construction Co. | Haginoya M.,Yahagi Construction Co. | Suzuki M.,Yahagi Construction Co. | Choi J.-H.,Korea University | And 2 more authors.
AIJ Journal of Technology and Design | Year: 2013

In Japan, many seismic retrofits are developed as a construction method which increases the safety of buildings in case of an earthquake. In recent years, seismic retrofits have been attracting attention as a construction method which raises the safety of buildings in case of an earthquake in South Korea. In addition, in order to spread seismic retrofits in buildings, it is important that they are able to be easily constructed. Therefore, this paper, suggests a metal connector that can be easily constructed in buildings and as a result of testing, it was clarified that the proposed metal connector can be applied to seismic retrofits.


Halim S.,Nagoya Institute of Technology | Takahashi S.,Nagoya Institute of Technology | Ichinose T.,Nagoya Institute of Technology | Teshigawara M.,Nagoya University | And 2 more authors.
Journal of Advanced Concrete Technology | Year: 2014

Part-1 of this study presents the experimental results of beam-column joints in soft-first story buildings, in which the first-story column depth is twice that of the upper stories. In Part-2, strut-and-tie models (STMs) are developed for the specimens. The flow of internal forces shown by the developed strut-and-tie models agreed with the observed cracks. The developed models for the joints are different from those for the usual joint: the main difference is that, in the specimens large struts were extended into the wall panel. STMs are also developed for the total frame to understand the overall equilibrium. Based on the STMs, new design equations are proposed, where the joint strength is evaluated as the sum of the flexural strengths of the beam and the second-story column. In I-type joint, the effect of the wall panel and beam stirrups is also considered. In O-type joint, the effect of the hoops in the joint is also considered. Copyright © 2014 Japan Concrete Institute.


Takahashi S.,Nagoya Institute of Technology | Halim S.,Nagoya Institute of Technology | Ichinose T.,Nagoya Institute of Technology | Kotani G.,Haseko Corporation | And 3 more authors.
Journal of Advanced Concrete Technology | Year: 2014

This study describes the strength of reinforced concrete (RC) beam-column joints in buildings with a soft first story. In such buildings, the sections of first-story columns are usually much larger than those of second-story columns to prevent story collapse. To investigate the strength of the beam-column joints, four specimens are constructed and the test is conducted with two types of joints: 1) the first-story column is extended toward the inside of the building (I-type joint) and 2) the first-story column is extended toward the outside of the building (O-type joint). The test parameters are the hoops in the beam-column joint, beam reinforcements, stirrups in the beam, and axial force. The beam longitudinal reinforcements are effective to prevent the yielding of the beam reinforcements in both types of joint. Stirrups in beam and hoops in joint strengthen I- and O-type joints, respectively. The force-resistant mechanisms of these joints are different from those of usual beam-column joints because sign of the bending moment in the second-story column is the same as that of the first-story column. The failure modes of these joints are also different from those of the usual beam-column joints. Copyright © 2014 Japan Concrete Institute.


Inai E.,Yamaguchi University | Takahashi K.,Taiyo Cement Industrial Corporation | Amano M.,Yahagi Construction Co. | Ishii K.,Taiyo Cement Industrial Corporation
AIJ Journal of Technology and Design | Year: 2013

The authors have been developing low-rise reinforced concrete masonry buildings with the wall thickness of 150mm, for the purpose of the increase of inner space of buildings, the decrease of building weight, and the usage of the standard building module of 300mm. In order to realize the buildings, compressive behaviors of fully grouted masonry prisms, using small-size concrete units with a strength of 40N/mm2 class and various grout materials with a strength more than 50N/mm2, were investigated. The used materials are concrete, mortar and non-shrink grouts with or without aggregate.


Izumi N.,Nagoya Institute of Technology | Takahashi S.,Nagoya Institute of Technology | Ichinose T.,Nagoya Institute of Technology | Teshigawara M.,Nagoya University | And 2 more authors.
Journal of Structural and Construction Engineering | Year: 2013

Experiments were conducted to study shear strength of wall located above an open frame. Based on the observed failure modes. A rigid-plasticity model was proposed. The shear strengths computed using the proposed model agreed with the observed ones. The vertical reinforcement in the wall panel, as well as the flexural and shear strengths of the boundary beam, greatly affected the shear strength of the wall.


Kamiya T.,Yahagi Construction Co. | Haginoya M.,Yahagi Construction Co. | Enomoto M.,Yahagi Construction Co. | Kohira W.,Yahagi Construction Co.
Journal of Structural and Construction Engineering | Year: 2015

In Japan, how to design structures to resist severe earthquake attacks is still one of the challenges today for our civil engineers. Then we should be obliged to present technological methods and guidance for prevention. A polyurea resin coating techniques has been well known that it is of effective to strengthen RC structures against impact and explosive events. To break a fresh method for retrofitting masonry structures against severe earthquakes, this study is to find experimentally the collapse preventive effects by polyurea resin coating of masonry structures. In shaking table tests, masonry block and brick walls with or without coating are tested. From test results, it is found that collapse prevention by polyurea coating can be remarkably improved.


Matsumoto N.,Nagoya Institute of Technology | Iwai K.,Nagoya Institute of Technology | Takakita T.,Ito Architects and Engineers Inc. | Seta S.,Nagoya Institute of Technology | Hasegawa H.,Yahagi Construction Co.
AIJ Journal of Technology and Design | Year: 2010

The purpose of this study is to clarify the effects and the problems of the practice process of the townscape improvement in Honmachi Nakasendo district in Nakatsugawa city. The process is cooperated by residents, administration and specialists. Following results are obtained; 1) To wnscape improvement practice plan is established. 2) Residents come to recognize the landscape plan exactly and tend to try environment improvement. 3) Administration starts moving to the next stages. 4) And the leader of the residents seem to be cultivated.


Matsumoto N.,Nagoya Institute of Technology | Takai C.,Nagoya Institute of Technology | Takakita T.,Ito Architects and Engineers Inc. | Hasegawa H.,Yahagi Construction Co.
AIJ Journal of Technology and Design | Year: 2010

The purpose of this study is to clarify the feature of the street view in old Makitani Street. After several experiments, the following results are obtained. First, we investigated this street, and we found a characteristic to an outer wall, a breast wall, and a door. Next, we did townscaping using the characteristic of this street. Then, we carried out an experiment to evaluate an impression. We clarified four elements which formed the impression of the streetscape. If the landscaping of the outside wall is done, it becomes united impressions, however, friendliness decreases.


Xu L.,Udagawa Kenchiku Sekkei Inc. | Hibino Y.,Tokyo Institute of Technology | Teshigawara M.,Nagoya University | Ban Y.,Yahagi Construction Co. | Umeno T.,Yahagi Construction Co.
Journal of Structural and Construction Engineering | Year: 2010

The slip behavior which damage concrete and deteriorate the performance of strength and ductility can be yielded on multi-story shear wall (MSSW) after flexural yielding under cyclic loading. This paper studied the mechanism of slip behavior on MSSW under cyclic loading after the flexural yielding by conducting experimental tests using column-shaped wall. Live specimens which were scaled models of 7-story MSSW were designed preceding flexural yielding. The parameters of specimens are axial load and arrangement of bond character of the main bars at the bottom of wall. The test results show that (1) in case that the axial force is zero, the slip behavior after the flexural yielding was occurred easily. (2) the result that the slip behavior after the flexural yielding can be controlled by increasing the axial load was verified, (3) the effectiveness of steel cylinders for stopping (controlling) slip behavior is also verified. (4) a method to estimate the stiffness and displacement on the slip behavior were presented; however, crushing of concrete at the bottom of wall should be considered by reinforcing.

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