• Proceedings of the Korean Geotechical Society Conference
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• 1995.10a
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• pp.201-210
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• 1995

In Resent years, urban tunnels have been more deeply constructed due to the congestion of buried steuctures. In such conditions, the shield method has become one of the popular urban tunnelling method by reason of several characteristics ; safety of construction, mimium environmental damage, and workbility. In tunnelling, the space which is tail-void are created between the ground and the other face of the primary lining. in other to reduce the ground seformation, it is important backfilling in tail-void. In this paper, the result of an experimental investigation undertaken to evaluate the physical and mechanical propeties of grouts composed of various mixtures of backfill materials. And the backfill injection model test was carried out considering the effects of tail-void.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.577-583
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• 2010

In this study, the effect of void formation resulting from gas hydrate dissociation or loss of some particles within soil structure on the strength of soil is examined. Beag-ma river sands with uniform gradation were used to simulate a gas hydrate bearing or washable soil structure. Empty capsules for medicine are used to mimic large voids, which are bigger than soil particle. Beag-ma river sand was miced with 8% cement ratio and 14% water content and compacted into a shear box. The number and direction embedded into a specimen. After 4 hours curing, a series of direct shear test is performed on the capsule embedded cemented sands. Shear strength of cemented sands with capsules depends on the volume and direction. The volume and direction formed by voids are most important factors in strength. A shear strength of a specimen with large voids decreases up to 39% of a specimen without void. The results of this study can be used to predict the strength degradation of gas hydrate bearing sediments after dissociation and loss of fine particles within soil structure.

• Ecology and Resilient Infrastructure
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• v.6 no.3
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• pp.137-144
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• 2019

This study carried out experimental investigation through measurements of void fraction of aerated flows generated near hydraulic structures. The imaging technique applying the shadowgraphy method was employed to quantify aeration by measuring void fractions. Aerated flows in the vicinity of a sloped weir and a stepped weir were measured using the imaging technique. Spatially distributed void fraction that was possible from gray images gives aeration rate of the flows over hydraulic structures with eco-environmental function. Aeration over the stepped weir takes place more strongly and widely in its front slope and downstream compared to the sloped weir.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.1
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• pp.55-62
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• 2019

Hayakawa Kunihiko introduced community space as an open space in Housing in Japan for the first time. We can find the continuity of his architectural intent from his three works (Atrium, Steps, Labyrinth) during the early period of his Housing buildings, In particular, from Labyrinth, his intent was expanded to cities through 'Urban Void', seeking communication and harmony. Accordingly, based on the architectural overview and a field survey of Labyrinth, an analysis was conducted using Space Syntax to investigate whether the space of an inner courtyard is being used as a community space for neighbors who pass through the courtyard and whether the courtyard plays the role of 'Urban Void' as intended by the architect. For this investigation, according to VGA, the courtyard showed the role of great visual connectivity and integration and facilitated connections to the center of the entire space. On the other hand, according to J-Graph, the access stairway connected to each household from the courtyard helped secure privacy in the midst of common space. Step Depth noted that a hierarchy of space was formed to ensure visual privacy within each unit household in addition to privacy for each household.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.1
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• pp.69-79
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• 2004

This Paper examines theoretical terrains and design strategies of landscape urbanism which is an emerging hybrid field at the intersection of architecture, landscape architecture, and urbanism. Landscape urbanism offers alternative approaches for theory, education, and practice in contemporary landscape architecture. It views the emergent urban complex sites-post-industrial sites, landfill, brownfield, urban void, etc., not as a weakness, but as a strength. Landscape urbanism poses an understanding of landscape as an element of urban infrastructure. In this sense, the landscape is seen in the context of contemporary urban development and public works. As a complex amalgam, landscape urbanism is more than a design style it is an ethos, an attitude, a way of thinking and acting. We can chart the main characteristics of landscape urbanism such as horizontality and surface, infrastructure, process, technique, and ecology. Multilayered examples of landscape urbanism can be seen in several experimental practices such as worts of Rem Koolhaas, MVRDV, Adriaan Geuze/West 8, James Comer, etc. It is possible to summarize the productive strategies for landscape urbanism as follows : thickening, folding, new materials, nonprogrammed use, impermanence, and movement.

• Korean Institute of Interior Design Journal
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• v.17 no.1
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• pp.77-83
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• 2008

MVRDV is most important architect as created interesting architectural space in contemporary architecture, and so they applies to the unique theory in their architecture. They used to architectural diagram, program, datascape, density as a design tool. Especially, they have create new architectural space and form in using architectural diagram, program, datascape, density, and void. So, this study is purposed to explain how they use as architectural tool to make composition of it's architectural space and is purpose to explain what is their main concept in architectural space. MVRDV's architectural space has fundamental methodology. That is Datascape on uncertainty and continuity between urban space and architectural space. The former consist in using diagram and architectural program and the latter consist in operating architectural void and inner continuity surface. The conclusion is follows 1. The mode of spacial composition by architectural void is correspond density of city as MVRDV's architectural thinking. 2. The mode of spacial composition by architectural program is ambiguous to the boundary between inner and exterior space by transparency. 3. The mode of spacial composition by architectural diagram make to generate the architectural form and space, through the reinterpretation and relocation of architectural program. 4. The mode of spacial composition inner continuity plane is make relative between site and inner space.

• Korean Institute of Interior Design Journal
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• v.27 no.3
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• pp.100-107
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• 2018

In order to overcome social exclusion and to integrate social housing, it is necessary to plan a communal space in urban collective housing so that residents can have belonging sense and community consciousness. In this study, it is necessary to consider the linkage between social integration and residential space, and to derive the characteristics of planning the collective housing for social integration. We analyzed the planning characteristics of MVRDV's communal spaces of collective housing and suggested a method of planning communal spaces of urban collective housing for social integration. Urban density is an important tool and background for MVRDV's design methodology. For this reason, MVRDV's collective housing is selected as a case study in this study. As a result of case analysis, openness and connection characteristics should be considered by using various devices such as glass exterior, balcony, and void in planning the communal space in urban collective housing for social integration. However, since it has appeared in many cases, it can be criticized that the application of this is merely a logic. In other words, it is possible to suggest that we should actively introduce less accessible access. This problem should be solved through more case studies.

• Journal of Korean Society of Steel Construction
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• v.29 no.6
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• pp.443-453
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• 2017

In this study, a trapezoidal hollow ball is used, instead of a spherical hollow ball commonly used in void slab, to secure the high hollow ratio in the deck type void slab. The bending and shear performance was measured with consideration for the shape change of the hollow ball. And to confirm the effect of deck plate and truss wire on shear performance, experiments were performed depending on the installation directions of the one-way deck plate. As a result, the bending performance of the deck type void slab with a trapezoidal hollow ball was similar to that of the void slab with a spherical hollow ball. However, according to the data of shear strength examined, the contribution of shear performance enhancement of the truss wire had a more effect on the shear performance of deck type void slab, rather than the influence by changing of the shape of hollow ball. In the previous studies, the shear strength is reduced to about 60%, due to the reduction of the effective section of concrete by installation of hollow ball. But in this experiment, the maximum load of specimen, in which the deck was installed in horizontal direction, so expected to have no influence on the shear performance, was only reduced to about 87%, due to the truss framework of truss wire.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.2
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• pp.225-236
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• 2014

Shear wave velocity was used to estimate the geotechnical characteristics (void ratio and shear strength) of ground near an underground rainfall storage facility. An oedometer cell was utilized to measure the shear wave velocity and the displacement of specimens. Shear strengths were obtained by direct shear tests. The relationships along the shear wave velocity, void ratio, and shear strength were verified and used to infer the shear strength profile with the depth. In addition, changes in shear strength due to the construction of the underground rainfall storage system were estimated using the suggested method. The results show that the in-situ shear strength deduced from the shear wave velocity-void ratio-shear strength relationship is in good agreement with that obtained from an in-situ investigation (SPT).

• Geomechanics and Engineering
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• v.29 no.3
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• pp.291-300
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• 2022

Tunnel boring machines combined with the earth pressure balanced shield method (EPB shield TBMs) have been adopted in urban areas as they allow excavation of tunnels with limited ground deformation through continuous and repetitive excavation and support. Nevertheless, the expansion of TBM construction requires much more minor and exquisitely controlled surface settlement to prevent economic loss. Several parametric studies controlling the tunnel's geometry, ground properties, and TBM operational factors assuming ordinary conditions for EPB shield TBM excavation have been conducted, but the impact of excessive excavation on the induced settlement has not been adequately studied. This study conducted a numerical evaluation of surface settlement induced by the ground loss from face imbalance, excessive excavation, and tail void grouting. The numerical model was constructed using FLAC3D and validated by comparing its result with the field data from literature. Then, parametric studies were conducted by controlling the ground stiffness, face pressure, tail void grouting pressure, and additional volume of muck discharge. As a result, the contribution of these operational factors to the surface settlement appeared differently depending on the ground stiffness. Except for the ground stiffness as the dominant factor, the order of variation of surface settlement was investigated, and the volume of additional muck discharge was found to be the largest, followed by the face pressure and tail void grouting pressure. The results from this study are expected to contribute to the development of settlement prediction models and understanding the surface settlement behavior induced by TBM excavation.