• Title/Summary/Keyword: Masonry structure

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Field test and research on shield cutting pile penetrating cement soil single pile composite foundation

  • Ma, Shi-ju;Li, Ming-yu;Guo, Yuan-cheng;Safaei, Babak
    • Geomechanics and Engineering
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    • v.23 no.6
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    • pp.513-521
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    • 2020
  • In this paper, due to the need for cutting cement-soil group pile composite foundation under the 7-story masonry structure of Zhenghe District and the shield tunnel of Zhengzhou Metro Line 5, a field test was conducted to directly cut cement-soil single pile composite foundation with diameter Ф=500 mm. Research results showed that the load transfer mechanism of composite foundation was not changed before and after shield tunnel cut the pile, and pile body and the soil between piles was still responsible for overburden load. The construction disturbance of shield cutting pile is a complicated mechanical process. The load carried by the original pile body was affected by the disturbance effect of pile cutting construction. Also, the fraction of the load carried by the original pile body was transferred to the soil between the piles and therefore, the bearing capacity of composite foundation was not decreased. Only the fractions of the load carried by pile and the soil between piles were distributed. On-site monitoring results showed that the settlement of pressure-bearing plates produced during shield cutting stage accounted for about 7% of total settlement. After the completion of pile cutting, the settlements of bearing plates generated by shield machine during residual pile composite foundation stage and shield machine tail were far away from residual pile composite foundation stage which accounted for about 15% and 74% of total settlement, respectively. In order to reduce the impact of shield cutting pile construction on the settlement of upper composite foundation, it was recommended to take measures such as optimization of shield construction parameters, radial grouting reinforcement and "clay shock" grouting within the disturbance range of shield cutting pile construction. Before pile cutting, the pile-soil stress ratio n of composite foundation was 2.437. After the shield cut pile is completed, the soil around the lining structure is gradually consolidated and reshaped, and residual pile composite foundation reaches a new state of force balance. This was because the condensation of grouting layer could increase the resistance of remaining pile end and friction resistance of the side of the pile.

Empirical seismic vulnerability probability prediction model of RC structures considering historical field observation

  • Si-Qi Li;Hong-Bo Liu;Ke Du;Jia-Cheng Han;Yi-Ru Li;Li-Hui Yin
    • Structural Engineering and Mechanics
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    • v.86 no.4
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    • pp.547-571
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    • 2023
  • To deeply probe the actual earthquake level and fragility of typical reinforced concrete (RC) structures under multiple intensity grades, considering diachronic measurement building stock samples and actual observations of representative catastrophic earth shocks in China from 1990 to 2010, RC structures were divided into traditional RC structures (TRCs) and bottom reinforced concrete frame seismic wall masonry (BFM) structures, and the empirical damage characteristics and mechanisms were analysed. A great deal of statistics and induction were developed on the historical experience investigation data of 59 typical catastrophic earthquakes in 9 provinces of China. The database and fragility matrix prediction model were established with TRCs of 4,122.5284×104 m2 and 5,844 buildings and BFMs of 5,872 buildings as empirical seismic damage samples. By employing the methods of structural damage probability and statistics, nonlinear prediction of seismic vulnerability, and numerical and applied functional analysis, the comparison matrix of actual fragility probability prediction of TRC and BFM in multiple intensity regions under the latest version of China's macrointensity standard was established. A novel nonlinear regression prediction model of seismic vulnerability was proposed, and prediction models considering the seismic damage ratio and transcendental probability parameters were constructed. The time-varying vulnerability comparative model of the sample database was developed according to the different periods of multiple earthquakes. The new calculation method of the average fragility prediction index (AFPI) matrix parameter model has been proposed to predict the seismic fragility of an areal RC structure.

A Study on Spatial Characteristics of Post-Disaster Interim Housing - Focusing on Asian Precedents of Natural Disasters - (재난 이후 임시주거의 공간특성 연구 - 아시아지역에서 발생한 자연재난을 중심으로 -)

  • Kim, sara;Nam, Kyung-Sook
    • Korean Institute of Interior Design Journal
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    • v.24 no.5
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    • pp.108-116
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    • 2015
  • This study intends to research the spatial characteristics of Asian interim housing that accommodates sufferers pro tempore after disasters. The scope of this research covers the interim spaces used for housing people after natural disasters that occurred in Asia for the past fifteen years. Within this scope, literature review was conducted as the basis to derive the characteristics and environmental elements of interim housing, which provided the criteria to compare and evaluate cases of interim housing along with characteristic elements required of interim housing found in previous studies. According to literature review, interim housing can be classified by life-span, region, economy, climate, type, number of household, square measure, residential cost, structure/material, and service life. Within the scope of the present research, literature review showed a total of twenty-eight cases of interim housing in fifteen countries revealing a high rate of disaster occurrence in the subtropic and tropic climate of Southeast Asia. A great percentage of interim housing was used for long-term stay of over a year. The structure of interim housing varied from lightweight steel, wooden, masonry, membrane, to traditional structure and the type were divided into temporary shelter, transitional housing, temporary housing, and permanent housing. Followed by literature review, the characteristics required of post-disaster interim housing were analyzed based on previous research and case studies. The characteristics of interim housing can be divided into environmental, technological, and socio-cultural ones. Sub-characterical items according to such division include amenity, health, surroundings, structure, convenience, eco-friendliness, safety, communication, and locality. As a result of evaluation, most items met the required characteristics of interim housing, while technological characteristics such as structure and convenience varied with the types of interim housing and appeared even unnecessary in some cases. According to analysis, amenity is maintained through the structural and material characteristics of interim housing and is also facilitated by increasing number of infrastructure such as educational, sanitary, and convenience facilities provided by the governmental and organizational bodies. It is expected that this study will be utilized as preliminary data for follow-up studies that improve the environment of post-disaster interim housing suitable for domestic circumstances in environmental, technological, and socio-cultural respects.

A Study on the Structure Behavior of Dry-assembled Wall with Concrete Blocks subjected to Cyclic Lateral Load (콘크리트블록으로 건식조립된 벽체의 수평반복하중에 대한 구조거동 연구)

  • Lee, Joong-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.6
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    • pp.440-447
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    • 2020
  • Masonry structures are used as bearing walls in small buildings, but they are generally considered non-bearing walls. They are used as partition walls that divide the interior spaces of the frame structures of buildings. In addition, wetting techniques that use mortar as an adhesive between blocks or bricks in construction are vulnerable to climatic conditions, especially cracks in mortar, which can cause conduction collapse of the walls in seismic loading. The purpose of this research was to propose a dry concrete block construction method that complements the weak axial shear stiffness and improves the weakness of the wet construction method as well as to investigate its structural behavior. In this study, the material properties of concrete blocks were examined, and the seismic performance of the proposed dry assembly structure was verified by structural behavior tests on horizontal cyclic loads. First, in these study results, concrete blocks can be applied to the dry block construction method instead of wet construction methods because they secure more than C-type blocks in KS regulations. Second, the structural performance of the wall against a horizontal cyclic load indicates that the resisting force of the assembly block wall is increased by increasing the horizontal length of the wall, forming several diagonal cracks. Finally, the proposed dry block wall structure requires a seismic performance assessment considering that the ratio of the shape of the wall by height and length is considered a major influence variable on the structural behavior under a horizontal load.

Influence on the Movement of Fish by the Installation of Structures in Mountain Streams: Focused on Chinese Minnow (산지계류에 설치된 계상구조물이 어류의 이동에 미치는 영향: 버들치를 중심으로)

  • Ma, Ho-Seop;Park, Jae-Hyeon
    • Journal of Korean Society of Forest Science
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    • v.108 no.2
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    • pp.224-232
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    • 2019
  • The movement of fish to the upper and the lower parts of a mountain stream was investigated based on the installation of specific types of structures within the stream. The results indicated that as the flow rate increases after a rain, the height of the drop in an open-type structure, such as a concrete box, is decreased so that the floating fishes, such as the Chinese minnow fish, move relatively easily from the upper to the lower parts and from the lower to the upper parts of the stream. In contrast, the fishes released from an upper point of a wall-type structure with <1 m, such as rocks drop works and stone masonry for stream-grade stabilization, were trapped in the lower part of the stream and, even after the rainy season, it was difficult for the fish to move from the lower to the upper parts of the stream. In particular, the barrier-type structures ${\geq}3m$ limit the movement of fish, even when there are few drainage holes at the lower end of the dam, and there is no space for the fishes to communicate with each other, even when the flow rate is high; therefore, although the fish are active, they are restricted to move according to the type and characteristics of the structures. When installing structures in a mountain stream, the height of the structure must be low enough to allow the fish to communicate with each other or an open-type structure must be installed. The fish habitat and water conditions within the stream must be considered when designing the type and height of the in-stream structures.

Case Study on the Characteristics of Hanok Hotel (한옥호텔의 배치 및 공간특성에 관한 사례조사)

  • Kim, Sunyoung;Hwang, Yeon-Sook
    • Korean Institute of Interior Design Journal
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    • v.23 no.6
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    • pp.169-177
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    • 2014
  • The purpose of this study is to analyze the design characteristics of Hanok hotel. This study was approached by using theoretical investigation and a field survey. The field survey analyzed the current situations by conducting the master plan layout, architecture and interior design of the Hanok hotel. The field survey was tested by examining four different Hanok hotels from February 2014 to July 2014. After all, the results were analyzed based on given categories. The results of this research can be summarized as following. First, the characteristic of the master plan layout in Hanok hotel was appeared as "ㄷ" and "ㅡ" shapes. Those layouts were based on the spatial and the functional aspects of Hanok hotel facilities. Second, three different structural methods such as the korean traditional wooden structure, concrete, and masonry method were used in Hanok hotel construction to deliver the traditional architecture aspects while considering the functionality and convenience of the building. Third, most of Hanok hotels had the limited furniture range. The consideration of using several types of traditional furniture in different rates of the guest rooms help to increase the service quality and customer's satisfaction. Fourth, there were no diversity of using materials and colors in Hanok hotels that only few of them were used to express the traditional look. Fifth, the local characteristics were found in several Hanok hotels. To reflect the local characteristics in Hanok hotel is to construct a suitable environment to fit in nature and also it is easily to convey the local culture to others.

A Study on the Healing Architecture of Health Promotion Villages (건강마을의 건축적 치유요소 연구)

  • Lee, Min-Ah
    • Journal of Families and Better Life
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    • v.29 no.5
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    • pp.1-17
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    • 2011
  • This study aimed to analyze health promotion villages from the perspective of therapeutic architecture, and to provide basic information for planning relevant health facilities. On the basis of a review of previous literature, the characteristics of therapeutic architecture were classified into eight categories: safety, comfort, sociality, autonomy, openness, diversity, privacy, and natural environment. Field study and observation were performed in four health promotion villages that conduct programs for lifestyle improvement, physical fitness, and treatment; these villages were also considered to have a healthy residential environment. The researcher and three assistants visited the facilities and checked utilization of space through interviews with the staff and guided tours. Basic information about the subject facilities, such as the purpose of establishment, was gathered from websites before visits. Two of the villages examined in this study had a traditional Korean wooden structure, while the other two were reinforced concrete and masonry block structures. All the facilities emphasized the use of environmentally friendly material and harmony with nature. Each site was divided into the following areas: office, residence, health/treatment, public/rest, and outdoor. The safety standards of the healing architecture were not completely satisfactory at all facilities. In particular, it was found that they lacked adequate universal design equipment. However, the healing characteristics of autonomy and diversity were strong. With regard to autonomy, the facilities allowed visitors to select indoor-outdoor moving lines and the use of front- and backyards constructed on slopes. In addition, they were equipped with many entries, staircases, void, terraces, and crossroads. The architecture was aesthetically designed using feng shui symbolism, and visitors found the scenes depicted in various spaces in the villages to be stimulating. Besides, the facilities were constructed using natural materials, had a natural indoor environment, and provided a sense of spaciousness and flexibility.

A Study on the Characteristics of Organic Design of Alvar Aalto (알바 알토(Alvar Aalto)의 유기적 디자인 특성에 관한 연구)

  • 이종선
    • Korean Institute of Interior Design Journal
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    • no.12
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    • pp.91-99
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    • 1997
  • Alvar Aalto has pursued National Romanticism, cultural art movement in scandinavian peninsula, organic concepts of growth and suitability, comprehensive view of nature including a possibility of coexistance of human-being and the nature well harmonized. For instance, his design expressed local features of the nature, human emotions instead of geometical arts and mathematical principles. It is noteworthy today that he built up the identity with satrical architecture vocabularies, different from modern arch-itechtural idiology. The characte-ristics of his design related to interior architecture are collectively as follows; The first, Space discontinuity of the interior and exterior, gradual process by joints which are inclined to collage with many shapes in plan and section of the space and such joints are adjusted by sensual ways and stressed with inner collectivity in his works. The second, He pursued the architectural orderfor modern irreqularity, various changes and sensual harmonies. As result, free curved line, fan shape and irregular modeling were individually expressed by technics of natural features and national characteristics of Finland. The third, Organic synthesis. A harmony through med-ums in its space, materials and space effectiveness relations are made and expressed for mixed design especially harmonized of all the materials he planned, entire harmony with total design, itemized details, materials and furnitures in entire space. The fourth, The interest of the nature based on his sense harmonized with nature made him mainly use native materials, lumbers and red bricks masonry and showed and arranged various interior sky light and grazed in to let natural light in, harmony with garden to sensually cohere to the nature and courtyard, etcetera. His major subject are to direct architectural developments through the nature and human-being in his works. At this point, it is considered that his direction of the locality and independence as a human-being made the concepts of organic space structure possible.

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A Study on Current Situation of Rural Community Facilities Applied Universal Design (마을회관의 유니버설디자인 현황에 관한 연구)

  • Lee, Eul-Gyu
    • Journal of the Korean Institute of Rural Architecture
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    • v.17 no.1
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    • pp.113-120
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    • 2015
  • In recent years, the population composition of rural area is changing due to the decreasing population growth of the aged with disability and people returning to farming. Since 1970's the rural community facilities have been spreaded out across most rural villages. Although the rural community facilities are the most widely used facilities, the existing facilities are need to be new built or remodeled according to demographic changes, usage of facilities, and environmental condition. Given this reality, the rural community facilities such as village assembly hall and nursing home for senior citizen are not only used for daily life place but also used like co-residence having meals and sleeping together. Therefore the rural community facilities have the potential to become welfare service space for rural elderly people. This research focuses on the current situation of universal design applied community facilities. According to the research, most of the village community facilities were built in the 1990s and 82% of the buildings were more than 15 years old. Furthermore, 45% of the village community facilities more than 15 years old most have a ground floor in masonry structure. The area of the building is 65% less than $100m^2$. The width of the access entrance, the height of the sink, gas safety valve and so forth were relatively well designed. However, the handrail of the entrance, space in front of the toilet bowl, the height difference between the entrance and floor, the installation of the width of the ramp and stair handrail was relatively incomplete. Village community facilities to be built in the future should be universal design fundamentally.

The Evaluation of Damage Behaviour of Adjacent Structures in Urban Excavation (도심지 흙막이 굴착시 인접구조물의 손상 평가연구)

  • 김학문;황의석
    • Journal of the Korean Geotechnical Society
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    • v.19 no.6
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    • pp.351-361
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    • 2003
  • Brick wall models with window opening, length 1.844m $\times$ height 0.6m, representing 2-story building was constructed on a scale of 1/10 of actual size of brick building for the investigation of damage mechanism. Six settlement troughs presenting six stages of excavation were simulated by Peck(1969) and O'Rourke et al.(1976) methods. The results from the model tests using Peck(1969) and O'Rourke et al.(1976) method indicated that angular distortion of brick wall by O'Rourke et at. method was 21% greater than that of Peck method. Horizontal displacement by O'Rourke et al.(1976) was 24% greater than that of Peck. When the degree of building damage for the O'Rourke et al. method of settlement trough is plotted on the damage level graph(Boscardin & Cording, 1989), damage level becomes much more severe than the level obtained by peck's method. Also, building stiffness and soil-structure interface are considered important factors of expressing building damage.