• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.8
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• pp.1295-1302
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• 2003

In order to evaluate a failure behavior of pipe with notch-type wall thinning, the present study performed full-scale pipe tests using the 102mm, Schedule 80 pipe specimen simulated notch- and circular-type thinning defects. The pipe tests were conducted under the conditions of both monotonic and cyclic bending moment at a constant internal pressure of 10 MPa. From the results. of experiment the failure mode, load carrying capacity, deformation ability, and fatigue life of a notch-type wall thinned pipe were investigated, and they were compared with those of a circular-type wall thinned pipe. The failure mode of notched pipe was similar to that of circular-type thinned pipe under the monotonic bending load. Under the cyclic bending load, however, the mode was clearly distinguished with variation in the shape of wall thinning. The load carrying capacity of a pipe containing notch-type wall thinning was about the same or slightly lower than that of a pipe containing circular-type wall thinning when the thinning area was subjected to tensile stress, whereas it was higher than that of a pipe containing circular-type thinning defect when the thinning area was subjected to compressive stress. On the other hand, the deformation ability and fatigue life of a notch-type wall thinned pipe was lower than those of a circular-type wall thinned pipe.

• Journal of Korean Association for Spatial Structures
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• v.19 no.4
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• pp.77-84
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• 2019

This study introduces a newly developed PC non-bearing wall system to prevent the damage of RC wall-type apartments that have been heavily damaged by the 2017 Pohang Earthquake. In order to evaluate the performance of the developed PC non-bearing wall system, a static cyclic test is conducted. The prototype of test specimen is from the RC wall-type apartment which has been severely damaged by the 2017 Pohang Earthquake. The specimen with the conventional non-bearing wall system showed the similar damage of RC wall type apartment suffered from the Pohang Earthquake. In case of the specimen with the developed PC non-bearing wall system, cracks and damages were not transmitted between the walls due to the seismic slit and there were almost no cracks in the non-bearing walls. Therefore, the proposed non-bearing wall system, separated from the structural walls, could prevent spreading cracks to bearing walls and make it possible to effectively control damage due to earthquake loads.

• Architectural research
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• v.13 no.3
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• pp.3-10
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• 2011

The Characteristics of space are determined by several factors; however, the element that determines the physical characteristic of floors, walls, and ceiling is the structure. This study constructs a wall to analyze the direct effect that the layout of an exhibition wall has on the element of the wall followed by the structural process and visibility of descriptive analysis and examples of art museums that the shift from a perceptional wall to an experiential wall affected circulation. For elements and formation methods of the wall, first, it is made up of open and closed type exhibition spaces, and it can give abundance in qualitative space rather than a quantitative aspect. Secondly, the directivity of space changes according to the development of the visible axis, thus, directly affects the change in visibility. Thirdly, the difference between spatial structure and visual structure is the difference between the visual axis and spatial structure. The wall formation type followed by the combination method, the simple visible structure, which is the type that possesses the simple combination (Room, Zone, Cluster), repeatedly uses the same size of units of space that is orderly and has few spatial axes and the classification of simple type and simple cluster type, which has few visible axes, also exists. Also, with the complex structure of the maze type it displays the reiterated form of the cluster, which is the space with disorderly combination and has much visible axes and spatial axes. Also, these can be divided into three types: 1) Maze Cluster Type, 2) Cross Road Type, and 3) Open Flexible Type. These wall types lead the various changes in circulation, and even each of the arrangement qualities of the exhibitions should be researched according to its exhibition place type.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.465-472
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• 1999

A small scale model reinforced soil wall was constructed in a laboratory to investigate role of the wall facing and the effect of construction sequence on the wall. A panel type facing system and a block facing system are introduced for test. These two different types of facing adapt different construction procedure. The model wall is built with geogrid reinforcement, sand, and the facings on rigid surface. The model wall is instrumented with earth pressure gauges, LVDTs, and strain gauges. It is found in this study that the reinforced soil wall system built with geogrids and panel type facing system be the safest reinforced soil wall ever compared to the block type facing. Thus, it is recommended that study for the wall system be necessary for further wide usage in the future.

• International Journal of High-Rise Buildings
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• v.10 no.3
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• pp.211-218
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• 2021

A new type of earthquake resilient reinforced concrete (RC) shear wall structure, installed with replaceable coupling beams and replaceable corner components at the bottom of wall piers, is proposed in this study. At first, the mechanical behavior of replaceable components, such as combined dampers and replaceable corner component, is studied by cyclic loading tests on them. Then, cycling loading tests are conducted on one conventional coupled shear wall and one new type of coupled shear wall with replaceable components. The test results indicate that the damage of the new type of coupled shear wall concentrates on replaceable components and the left parts are well protected. Finally, a case study is introduced. The responses of one conventional frame-tube structure and one new type of structure installed with replaceable components under the wind and the earthquake are compared, which verify that the performance of new type of structure is much better than the conventional structure.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.679-687
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• 2014

In this study, a new paint which is able to resist the cavitation erosion is tried to be developed by using urethane added with nano particles such as multi-wall and single-wall carbon nano tube and spherical and fiber type graphite. The new paint synthesized was characterized with physical properties and resistivity to cavitation erosion($t_{50}$). Among nano particles, fiber type graphite($t_{50}$ 292min) showed high hardness and wear resistance compared with spherical type($t_{50}$ 182min). For carbon nano tube, single-wall type($t_{50}$ 286min) was higher than multi-wall type in wear resistance. Fiber-type graphite was the best nano-particle for paint with resistivity to cavitation erosion. In the application test of paint, the manually painted sample showed surface with smooth but the surface of sample prepared with spray was not smooth. During spray, dust was fixed on the surface.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.188-189
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• 2014

Recently, structural system of apartment building is changing from wall type to column type to accommodate various life styles of residents in Korea. Reinforced-concrete bearing wall structures have been mainly used in apartment construction since 1980's. It is impossible to remove the bearing wall in case of remodeling a house, so that the lightweight wall is needed to apply to the column type structure of the Long Life Housing. Therefore, the purpose of this study is to evaluate the construction performance of the wall. Constructibility reviews are performed throughout interview survey from builders who charge with managing the construction of the lightweight wall in field. This paper present that constructor prefer the bearing wall rather than the lightweight wall because of the schedule delay, difficulty of management, and lack of skilled labor. The results indicate what we should improve on the lightweight wall from now on.

• Journal of Conservation Science
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• v.2 no.2 s.2
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• pp.15-24
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• 1993

To understand the morphological change of ancient woods, samples classified by cell type, burial environment and species were collected and observed using microscopy. Decay of wood by cell type could classified into two types. First, degraded secondary wall was formed granular residues in $S_2$ layer and was remained $S_3$ layer and compound middle lamella. Second, the cell wall was slightly degraded and cracked in secondary wall. A gradual thinning of cell wall was occured. The compound middle lamella was separated from secondary wall. The resistance of degradation is increased at vessels, parenchyma, and tracheid and wood fiber in the order named. The type of degradation by species could be classified into four types. Overall degradation type; the degradation of cell wall is usually heavy and the extent of degradation Varies by part of the same sample. Partial degradation type ; this type shows severely different decay type by part of the sample. Nondegraded cells were mixed with degraded cells on the same sample. Erose degradation type ; thinning of the cell wall was occoured and the degradation type was different by part. Slight degradation types ; secondary wall was slightly degraded, cracked and separated from compound middle lamella. Considering different type of burial environment, dry wood was similiar to sound wood and slightly decayed. Waterlogged and peat burial wood was heavilydecayed. Between species of under the same environment, decay type and extent were diferentiated from each other.

• Wind and Structures
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• v.22 no.5
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• pp.555-571
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• 2016

A hanging-type sand-retaining wall is a very common sand-blocking fence structure used to prevent sand movement. This type of wall is widely used along the Qinghai-Tibet and Gobi desert railways in Xinjiang, Western China. To analyze the characteristics of wind-sand flow fields under the effect of such a sand fence structure, a wind tunnel test and a field test were carried out. The wind tunnel test showed the zoning characteristics of the flow fields under the effect of the hanging-type sand-retaining wall, and the field test provided the sediment transport data for effective wind-proof interval and the sand resistance data in the front and behind the sand-retaining wall. The consistency of the wind-sand flow fields with the spatial distribution characteristic of wind-carried sand motion was verified by the correspondences of the acceleration zone in the flow field and the negative elevation points of the percentage variations of the sand collection rate. The spatial distribution characteristic of the field sand collection data further showed the spatial structural characteristic of the sandy air currents under the action of the hanging-type sand-retaining wall and the sand resistance characteristic of the sand-retaining wall. This systematic study on the wind-sand flow fields under the control of the hanging-type sand-retaining wall provides a theoretical basis for the rational layout of sand control engineering systems and the efficient utilization of a hanging-type sand-retaining wall.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.507-510
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• 2005

Euro form which constructs the present RC structures is used widely by the form method of construction of a wall type structure had much consumption of the human power and equipments by the assembly and the demolition, and the complement was required according to demerit with much leakage of cement paste by the form joint, so it developed the new pillar type form system. On the study, in order to consider the modification characteristic by lateral pressure which does the influence most important for the new developed pillar type form system performance, research of a paper manufactured a miniature wall form model, and advanced performance evaluation focusing on lateral pressure. Moreover, lateral pressure evaluation of a new style system was actually gone on through the on-site experiment about a part of wall type srutcture spot for a model experiment and its result on the foundation which is the purpose in evaluating on-site application possibility propriety at the foundation time of wall type concrete structure construction of a pillar type form system.