• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.4
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• pp.387-402
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• 2014

In congested urban areas, constructions of tunnel structures have became necessary due to a lack of surface space. The excavation of any tunnel generated the ground disturbances of surrounding ground and displacements is major concern. Therefore, a study of tunnel stability is necessary. In this study, the authors have investigated the stability and failure pattern of tunnel through the model tunnel test. In this study, the close range photogrammetry was used to measure the ground deformation. The measured data was converted to displacement vectors and contours. And then it compared to FE analysis and empirical formula. In addition, this study presented the comparison between steel pipe reinforced model tunnel and unreinforced model tunnel. The ground deformation for both the steel pipe reinforced model tunnel and the unreinforced model tunnel was analysed.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.3
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• pp.72-87
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• 2000

The purpose of this research was analysis of biotope structure focused on the evaluation for the nature experience and recreation in the case of Suseoung District in Daegu metropolitan area. The results of this study were as follows; 1) The result of biotope type classification was divided into 17 biotope type groups and 90 biotope types belonging to them. 2) In the result of the first evaluation for the nature experience and recreation, biotope types such as MA, NA, OE, PH, QB etc. possess great value. Particulary these biotope types come from forest areas and transition zone. The have not appeared in the inner of cities. 3) The biotope types such as JC, ME, OA, OE, PB, QD, QF etc. are proved to possess high value in the result of the utility evaluation. 4) There emerges 3a biotope type that has the highest value in the result of the second evaluation - such as ME, NB, NC, PD, QB etc. Most of them range widely except in the urbanized areas. Most of them were presented into the large area of site size and in the outer forest areas. But most of them were distributed in the forest areas intensively. So, it is certain that the space of nature experience connected with residential district of the urban people s scarce. Finally, the detailed plan must be made out specially continuously. It is about biotope spaces that are important for the nature experience and the recreation from the result of this research. Also, the study on the detailed index settlement of the sight green plan based on the biotope map must be continued.

• Journal of Korean Society of Rural Planning
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• v.12 no.4 s.33
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• pp.63-76
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• 2006

This research tried to present some basic data necessary to give effective support to urban retirees who already returned to the farm by looking into factors effecting on their adjustments to the lives before they returned to the farm and after they did so to know how well they adapt to the rural lives. For the purpose, we made a survey of 408 returners to the farm over the age of 50 for 6 days from October 18 to October 23 in 2004 using questionaires. The results show the followings. First, there are significant difference in the satisfaction with the rural life occurred by the sociological demographic changes according to 'health condition', 'subjective economic ability' and 'previous job'. Second, the difference of satisfaction with the rural lift which was taken place by the reasons before they moved to the farm is effected considerably by what made them decide to return to the farm first whether they prepared for it or not and how much money they have to do so. Therefore, to succeed in adjustment to the rural lives, their decision should be made by positive causes, they have to prepare concretely for it before they carry out their plans and they had better have enough money to move. Third, the difference of satisfaction with the rural life occurred by the reasons after they moved to the farm is effected by 'satisfaction with the forming information', 'the number of friends or neighbors', 'the frequency of meeting the friendly', 'the level of intimacy with neighbors' and 'their efforts to improve the relations with other residents'. And the sensitiveness to perceive the inconvenience according to the rural life is related strongly to the satisfaction with the rural life in the above 6 areas. Fourth, the repression analysis implemented to find how much the above 3 factors effect on the satisfaction with the rural life shows that it is 'returner's current health condition', 'farming education', 'farming fund' and 'effort to be intimate with other residents' that are very important.

• Journal of the Korea Society of Computer and Information
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• v.11 no.4 s.42
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• pp.221-230
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• 2006

Changing drastically, the life in a modern city has forced citizens to gradually shorten their average period of settlement, which has weakened the identity of city habitation, thus causing serious crimes and damaging the security of city greatly. Haying a highly composite structure with not only macro, but micro characteristics, city is grasped as a very composite phenomenon shown in the social, economic and spatial constitution relationships, including the personal motives of criminals. Accordingly, this study puts stress on the necessity of any crime prediction program to predict the occurrence of crimes by analyzing the occurrence patterns of sharply increasing intra-city crimes of violence on a typical, time and spatial basis and clarifying their structural dynamic relationships in a both macro and micro manner. Moreover, the deduction of various factors closely related to crime occurrence will contribute to elucidating the occurrence structure of city crimes.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.5
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• pp.699-715
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• 2019

Recently, in urban areas, cavities and ground collapse adjacent to underground structures are frequently reported. Several studies on the cavity generation by structure cracks have been made, however they are focused on the cause of cracks and settlement of the ground. In this paper, soil particle and groundwater discharge through pipe cracks and cavity generation mechanism are investigated. The theoretical analysis of the groundwater, which is the main factor of the drainage of the soil particles, and the particle transport mechanism and flow characteristics were investigated. An experimental model test was carried out to identify the mechanism of cavity generation by underground buried pipe cracks. The soil particle weight of discharge through the cracks, and the movement characteristics of the particles were analyzed using PIV. In this study, it is clearly identified that soil particle movements, cavity generation and ground collapse that occur in the ground are basically caused by the movement of groundwater.

• Journal of the Korean GEO-environmental Society
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• v.12 no.9
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• pp.5-11
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• 2011

Recently, large and deep excavations are increasing. The damage of adjacent structures due to excavation has steadily increased with increasing construction demand. Especially in urban development and poor conditions, the excavation adjacent to the subway structures has caused a lot of problems. This paper was reviewed that the underground excavation and reinforcement of the status process through a case study on the field. And stability analysis through the case study evaluates applicability for reasonable reinforcement method by numerical analysis. As a result, the strata distribution condition of all 16 sites consisted of landfill from the top and distributed in the order of deposits, weathered soils, weak rock from the bottom. Also, when proceeding the excavation adjacent to structures, the location of site and layer conditions have highly effect on the results of the construction. Therefore, this study was applied reinforcement method to protect damage by excavation. Displacement and settlement were within allowable criterion and hence, stability of structure was analyzed as safe.

• Journal of Korean Society of Rural Planning
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• v.28 no.2
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• pp.61-69
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• 2022

This study categorizes and identifies the characteristics of the living areas of rural dwellers through cluster analysis using mobile floating population data. As a result, rural areas in Korea were classified into 34 rural living areas, and 5 types of rural living areas were derived. Although the 'Suburban in Mega City Areas' and 'Suburban in Regional City Areas' derived through this study have advantages in terms of accessibility to large cities, they are important for rural space management as they can undermine the unique values of rural areas due to urban expansion. In addition, 'Unclassified areas' have low accessibility in the national space, and there is a need to provide their own settlement environment. The population of rural areas in Korea exhibited a phenomenon of widespread migration. This means that rural residents who depend on metropolitan areas are provided with SOC beyond administrative boundaries. Therefore, there is a need to move away from establishing a homogeneous regional plan that does not consider population movement. Through this study, it was possible to understand the rural living area formed by the population movement occurring in the rural area. This is different in that the existing studies classified the national space based on the interconnectedness between regions, beyond the limitations of categorizing regions with homogeneous characteristics based on endogenous indicators. At this point in time when the need for a rural space plan is emphasized, it is important to understand the living area of rural dwellers and to design an appropriate rural plan. Therefore, the establishment of a rural plan suitable for the region using the results of this study can increase the efficiency of the project for revitalization of the rural area and contribute to the creation of an attractive national space.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.4
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• pp.509-517
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• 2022

The demand for underground infrastructures such as tunnels is expanding due to rapid urbanization. Tunnels in urban areas are usually constructed adjacent to structures supported by piles. Therefore, a proper understanding of pile-tunnel interaction due to tunnel excavation activities is vital. Thus, in this study, a numerical analysis is conducted to analyze pile settlements, ground surface settlements and shear deformations above an existing tunnel subject to the presence of an adjacent tunnelling, with vertical offsets, the number of piles and the pile spacing considered as variables in the analysis. The results show that the vertical offsets between the tunnel crown and the pile tip generatelarger settlement than the pile spacing. In addition, the vertical offset shows an inversely proportional relationship to the shear deformation due to new tunnelling.

• Journal of the Korean Geotechnical Society
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• v.37 no.11
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• pp.7-22
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• 2021

In this study, inverse analysis was performed on the bi-directional axial compressive load test conducted on drilled shafts. And the bearing capacities were analyzed by numerical analysis of various pile tip ground conditions of silt clay, silt sand, sand silt, sand gravel, weathered rock, and soft rock. The bearing capacities were analyzed using the P-S method, the Davisson method, and the allowable sttlement of 25.4 mm. The minimum allowable bearing capacities analyzed by three methods were found to be 19.64 MN ~ 24.96 MN. At this time, the base resistances were sharing a 2% ~ 12% of a head load, shaft resistance were shared 88% ~ 98% of the head load. The greater the strength of pile tip was found to increase the allowable bearing capacity. However, the difference between the maximum allowable bearing capacity and the minimum allowable bearing capacity was 5.32 MN, and the increase in the allowable bearing capacity was only 27% depending on the pile tip.

• Journal of the Korean Geotechnical Society
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• v.22 no.2
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• pp.19-28
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• 2006

Long-term field observations were performed in three excavation sites in order to investigate the displacement behavior of adjacent ground during overall excavation procedure, where the depths of deep excavations were 15 m$\∼$29 m. In this study, ground settlements and lateral displacements of braced wall measured during installation of retaining wall and removal of bracing were specially focused to evaluate the behavior quantitatively according to three-stage-divided procedure, i.e. pre-excavation, main excavation, and removal of bracing. Through field measurements on three excavation sites, lateral displacements induced during removal of bracing are approximate to 40$\%$ of the amount found during main excavation stage and additional adjacent ground deformation during post-excavation procedure ranges from 18$\%$ to 33$\%$ of that found during main excavation stage, based on the settlement volume. In conclusion, it was quantitatively identified in this study that the deformations of adjacent ground during pre- and post-excavation stage were not negligible.