• Structural Engineering and Mechanics
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• 제33권5호
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• pp.635-647
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• 2009

For the calculation of foundation settlement it is recommended to take into account so called influence zone inside the subsoil bellow the foundation structure. Influence zone inside the subsoil is the region where the load has a substantial influence on the deformation of the soil skeleton. The soil skeleton is pre-consolidated or over consolidated due to the original geostatic stress state. An excavation changes the original geostatic stress state and it creates the space for the load transferred from upper structure. The theory of elastic layer in Westergard manner is selected for the vertical stress calculation. The depth of influence zone is calculated from the equality of the original geostatic stress and the new geostatic stress due to excavation combined with the vertical stress from the upper structure. Two close formulas are presented for the influence zone calculation. Using ADINA code we carried out several numerical examples to verify the proposed analytical formulas and to enhance their use in civil engineering practice. Otherwise, the FEM code accuracy can be control.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.213-217
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• 2004

Laboratory scale study for an area of influence and flowing aspect of groundwater saturated zone was conducted for three sediment grains. On the AMG(Average Modal diameter Grains) 0.34, 1.38, 3.89mm diameter samples, the affected area of the aquifer were 15.2, 37.0, 30.0%/m2 each. Air flow for AMG 0.34mm diameter grain size provides indication of pattern of channelized air flow in saturated zone and expansion state in above saturated zone. For AMG of 1.38, 3.89mm diameter grains, air flow are pervasive air flow, forming a symmetrical cone of influence around the injection point. And also AMG 1.38, 3.89mm diameter samples show onset of collapse and approach to steady state in above saturated zone, respectively. In this study, optimal sites for in situ air sparging, may be grain diameters between about AMC 1.5～2.5mm diameter.

• Geomechanics and Engineering
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• 제31권5호
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• pp.505-518
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• 2022

This study introduces soil resistance multipliers at locations encompassed by the zone of influence of the helix plate to consider the added lateral resistance provided to the helical pile. The zone of influence of a helix plate is a function of its diameter and serves as a boundary condition for the modified soil resistance springs. The concept is based on implementing p-multipliers as a reduction factor for piles in group action. The application of modified p-y springs in the analysis of helical piles allows for better characterization and understanding of the lateral behavior of helical piles, which will help further the development of design methods. To execute the proposed method, a finite difference program, HPCap (Helical Pile Capacity), was developed by the authors using Matlab. The program computes the deflection, shear force, bending moment, and soil resistance of the helical pile and allows the user to freely input the value of the zone of influence and Ω (a coefficient that affects the value of the p-multiplier). Results from ten full-scale lateral load tests on helical piles embedded at depths of 3.0 m with varying shaft diameters, shaft thicknesses, and helix configurations were analyzed to determine the zone of influence and the magnitude of the p-multipliers. The analysis determined that the value of the p-multipliers is influenced by the ratio between the pile embedment length and the shaft diameter (D_p), the effective helix diameter (D_h-D_p), and the zone of influence. Furthermore, the zone of influence is recommended to be 1.75 times the helix diameter (D_h). Using the numerical analysis method presented in this study, the predicted deflections of the various helical pile cases showed good agreement with the observed field test results.

• Geomechanics and Engineering
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• 제11권4호
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• pp.553-570
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• 2016

A series of three-dimensional (3D) parametric finite element analyses have been performed to study the influence of the relative locations of pile tips with regards to the tunnel position on the behaviour of single piles and pile groups to adjacent tunnelling in weathered soil. When the pile tips are inside the influence zone, which considers the relative pile tip location with respect to the tunnel position, tunnelling-induced pile head settlements are larger than those computed from the Greenfield condition. However, when the pile tips are outside the influence zone, a reverse trend is obtained. When the pile tips are inside the influence zone, the tunnelling-induced tensile pile forces mobilised, but when the pile tips are outside the influence zone, compressive pile forces are induced because of tunnelling, depending on the shear stress transfer mechanism at the pile-soil interface. For piles connected to a cap, tensile and compressive forces are mobilised at the top of the centre and side piles, respectively. It has been shown that the increases in the tunnelling-induced pile head settlements have resulted in reductions of the apparent factor of safety up to approximately 43% when the pile tips are inside the influence zone, therefore severely affecting the serviceability of the piles. The pile behaviour, when considering the location of the pile tips with regards to the tunnel, has been analysed in great detail by taking the tunnelling-induced pile head settlements, axial pile forces, apparent factor of safety of the piles and shear transfer mechanism into account.

• 한국환경과학회지
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• 제22권7호
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• pp.895-903
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• 2013

This study analyzed on characteristics of the ground-water capture zone in coastal areas and mid-mountainous area according to pumping rate. For this study, it targeted Jejudo island where is the volcanic island. To analyze, MODFLOW model and MODPATH model, which are the ground-water flow analysis models, were used. As a result of research, the following conclusions could be obtained. As a result of analyzing influence of a change in pumping time upon length of capture zone, the length of capture zone in coastal area was indicated to be greater in the changing ratio compared to the length of capture zone in mid-mountainous area. Next, in the coastal area, the pumping rate and the capture-zone length are changing similarly. However, in mid-mountainous area, the length of capture zone was indicated to grow when the pumping rate comes to exceed 1,500m3/day. As a result of analyzing influence of a change in pumping time upon capture area, the tendency of a change in the area was indicated similarly in coastal areas and mid-mountainous area. Especially, it could be known that the larger pumping rate leads to the more definite increase in tendency to a change in capture area. Based on this study, it was allowed to be possibly used in the suitable pumping rate in coastal areas and mid-mountainous area of the volcano island in the future. A follow-up research is judged to necessarily analyze the influence of tubular-well group upon capture zone by additionally analyzing a change in capture zone targeting the concentrated tubular well.

• 대한토목학회논문집
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• 제36권6호
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• pp.1093-1099
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• 2016

현재 우리나라의 수도권 전철역이 499개가 있지만 철도역과 연계수단간의 연계영향권에 대한 연구가 많지 않다. 대부분 진행된 연구들은 연계영향권보다는 접근영향권에 대한 연구가 주를 이루고 있다. 또한 연계영향권의 연구들은 설문조사와 기초통계자료를 이용하여 연계영향권의 설정에 대한 이론적기반과 분석기법에 한계를 가지고 있다. 본 논문에서는 새로운 연계영향권을 설정 방법론을 정립하고 이를 빅데이터인 교통카드 이용자들의 철도역 이용 공간자료와 GIS 기반 연계영향권 분석 기법을 접목하여 수단별 네트워크 통행시간기반 연계영향권 설정 연구를 수행 하였다. 연구결과 마을버스 15분이내, 지선버스 20분이내, 간선버스 25분 이상 등의 연계영향권이 네트워크 접근시간의 차이에 따라 명확히 구분됨을 확인하였다.

• 한국안전학회지
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• 제28권5호
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• pp.71-77
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• 2013

This Study aims at investigating actual condition on attending school road of children and analyzing empirically the characteristics of cognition and the influence of safety on school road. This study findings are as follows : 1) Walking alone to go to school is the highest rates among Commuting Mode, and Commuting distance to school is nearly doubles than range of school zone(300 m). 2) Among characteristics of urban spatial structure affecting on influence classify safety of school road, 'Commuting Distance' has been drawn to most influential variable. Especially, there are 4 types classified by commuting distance and it became obvious that the longer the distance, the lower the safety score(under 127 m=76.9 points, Over 451 m=58.3 points). 3) As a result of investigating the influence of Safety on attending school road, Vehicle commuting speed urder 127 m as internal of school zone, and Walking and crossing convenience over 451 m as external of school zone have a lot of influence on safety cognition on school road. Therefore Safety on school road should be considering the commuting distance to school among surrounding characteristics, needed for improvement plan and program based on real safety cognition of children.

• Advances in Computational Design
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• 제4권4호
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• pp.327-342
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• 2019

Rehabilitation and retrofitting of structures designed in accordance to standard design codes is an essential practice in structural engineering and design. For steel structures, one of the challenges is to strengthen the panel zone as well as its analysis in moment-resisting frames. In this research, investigations were undertaken to analyze the influence of the panel zone in the response of structural frames through a computational approach using ETABS software. Moment-resisting frames of six stories were studied in supposition of real panel zone, different values of rigid zone factor, different thickness of double plates, and both double plates and rigid zone factor together. The frames were analyzed, designed and validated in accordance to Iranian steel building code. The results of drift values for six stories building models were plotted. After verifying and comparing the results, the findings showed that the rigidity lead to reduction in drifts of frames and also as a result, lower rigidity will be used for high rise building and higher rigidity will be used for low rise building. In frames with story drifts more than the permitted rate, where the frames are considered as the weaker panel zone area, the story drifts can be limited by strengthening the panel zone with double plates. It should be noted that higher thickness of double plates and higher rigidity of panel zone will result in enhancement of the non-linear deformation rates in beam elements. The resulting deformations of the panel zone due to this modification can have significant influence on the elastic and inelastic behavior of the frames.

• 한국안전학회지
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• 제30권6호
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• pp.139-147
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• 2015

This study deals with actual commuting distance and influence of risk factors depending on commuting distance and mode in order to reestablish actual commuting zone of primary school students. Data mining analysis(CHAID) was applied for this reestablishment using survey results from 6,927 primary school students in Seoul Metro. Six risk factors; convenience level of commuting path condition, convenience level of road crossing condition, vehicle speed on commuting path, segregation level between commuter and vehicle, congestion level of commuting path, and public security level and two mode; walking and cycle are considered in the analysis. As the results of CHAID analysis, commuting distance was divided into four zones; Internal Zone(0.491km under), External Zone(0.492 ~ 1.492km, 1.493 ~ 2.699km), Commutable Zone(2.70km over), and awareness level on safety is declined as commuting distance is increased. The risk factor affecting on safety is recognized differently by students depending on commuting distance and mode. For students commuting by walking, vehicle speed on commuting path and convenience level of commuting path condition are recognized as the prime risk factor within Internal Zone and Commutable Zone, respectively. For students commuting by cycle, convenience level of road crossing condition and vehicle speed on commuting path are recognized as the prime risk factor within Commutable Zone. Analysis results show that improved plan and program for commuting path for primary school students are required considering actual commuting distance and method.

• 대한토목학회논문집
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• 제26권2D호
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• pp.335-340
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• 2006

임하호 유역은 지질 및 지형이 토사유실에 취약한 구조를 가지고 있어 강우발생시 많은 토사가 호소로 유입되어 고탁수의 원인이 되고 있다. 특히 임하호유역의 농경지가 주로 하천주변에 분포하고 있어 강우시 토사유실로 인한 탁수발생이 큰 지역이다. 따라서, 탁수저감을 위한 수변구역의 체계적인 관리와 대책 마련을 위해서는 수변구역에서 발생하는 토사유실량의 영향을 평가하는 것이 중요하다. 본 연구에서는 GIS 기반 RUSLE 모형을 선정하여 수변구역에서의 토사유실 비율을 평가한 결과 약 12.23%로서 임하호 전체유역과의 면적비율(9.95%) 보다 높게 나타남을 알 수 있었다. 이러한 결과는 수변구역 주변의 농경지비율(27.24%)이 전체유역에 대한 농경지비율(14.96%) 보다 높은 특성이 반영된 것으로 해석된다. 또한 소유역별 분석결과를 볼 때 수변구역중 대곡천 유역이 가장 높은 토사유실량 분포를 나타냈으며, 반변천_10 그리고 서시천 순서로 나타났다.