Doohyun Kyung

Bio: Doohyun Kyung is an academic researcher from Yonsei University. The author has contributed to research in topics: Pile & Transmission tower. The author has an hindex of 7, co-authored 24 publications receiving 1152 citations. Previous affiliations of Doohyun Kyung include Korea Electric Power Corporation.

Comparative Influences of Precipitation and River Stage on Groundwater Levels in Near-River Areas

Abstract: The sustainable performance of foundations of various urban buildings and infrastructures is strongly affected by groundwater level (GWL), as GWL causes changes in the stress state within soil. In the present study, the components affecting GWL were investigated, focusing on the effects of precipitation and river stage. These components were analyzed using a six-year database established for hydrological and groundwater monitoring data. Five study regions for which daily measured precipitation, river stage, and GWL data were available were compared. Different periods of precipitation, geographical characteristics, and local surface conditions were considered in the analysis. The results indicated that key influence components on GWL are different depending on the hydrological, geological, and geographical characteristics of the target regions. River stage had the strongest influence on GWL in urban areas near large rivers with a high ratio of paved surface. In rural areas, where the paved surface area ratio and soil permeability were low, the moving average showed a closer correlation to GWL than river stage. A moving average-based method to predict GWL variation with time was proposed for regions with a low ratio of paved surface area and low permeability soils.

Estimation of Lateral Load Capacity of Rigid Short Piles in Sands Using CPT Results

Abstract: Conventional methods for the estimation of the ultimate lateral pile load capacity are typically based on certain expressions of the lateral soil resistance pu and assumed distributions of the lateral soil pressure mobilized along the pile embedded depth. When soils are nonhomogenous, however, the application of conventional methods represents significant difficulties due to the nonlinear and irregular variation of pu with depth. In this study, a cone penetration test (CPT)-based methodology for the estimation of the ultimate lateral pile load capacity Hu was proposed, which can take full account of entire soil profile through the CPT cone resistance qc . A normalized correlation between qc and pu was proposed with correlation parameters corresponding to different existing methods. In order to validate the proposed CPT-based methodology, case examples of laterally loaded piles in various soil conditions were prepared and used to compare values of Hu from original and proposed methods. Calibration chamber ...

Vertical load-carrying behavior and design models for micropiles considering foundation configuration conditions

Abstract: In the present study, the vertical load-carrying behavior of micropile foundations with various configuration conditions was investigated based on results from model load tests. Considered configuration conditions included micropile inclination angle, spacing of micropiles, and types of micropile foundations. The ultimate load capacity of micropiles varied with installation angle, showing an initial increase and peak followed by a gradual decrease with further increase in installation angle. The ultimate load capacity of micropiled rafts was affected by both installation angle and micropile spacing. The load-carrying mechanism of micropiles for the inclined condition was proposed based on the decomposed axial and lateral load and resistance components. Using the proposed load-carrying mechanism and test results obtained in this study, the load capacity ratio for an inclined micropile was proposed. The group effect and interaction effect factors for group micropiles and micropiled rafts were proposed, resp...

Interpretative analysis of lateral load-carrying behavior and design model for inclined single and group micropiles

Abstract: In this study, the lateral load–carrying capacity of micropiles was investigated focusing on the effect of micropile inclination. A series of model load tests was conducted for both single ...

Improved Performance of Connected Foundations for Resilient Energy Transmission Infrastructure in Soft Soils

Abstract: The connected foundation is an effective structural type of foundation that can improve the sustainability of electrical transmission towers in soft soils to serve as a resilient energy supply system. In this study, the performance of electrical transmission towers reinforced with connected beams was investigated using a series of field load tests. Model transmission tower structures were manufactured and adopted into the tests. Based on the load capacity mobilization and failure mechanism, a criterion to define the load carrying capacity for connected foundation was proposed. It was found that the performance of connected foundation varies with the mechanical property of connection beam. The load capacity and differential settlement increased and decreased, respectively, with increasing connection beam stiffness. Such effect of connection beam was more pronounced as the height of load application point or tower height (zh) increases. Based on the load test results, a design model was proposed that can be used to evaluate the sustainable performance and load carrying capacity of connected foundations. Field load tests with prototype transmission tower structure models were conducted to check and confirm the performance of connected foundation and the proposed design method.

Three pillars of sustainability: in search of conceptual origins

Abstract: The three-pillar conception of (social, economic and environmental) sustainability, commonly represented by three intersecting circles with overall sustainability at the centre, has become ubiquitous. With a view of identifying the genesis and theoretical foundations of this conception, this paper reviews and discusses relevant historical sustainability literature. From this we find that there is no single point of origin of this three-pillar conception, but rather a gradual emergence from various critiques in the early academic literature of the economic status quo from both social and ecological perspectives on the one hand, and the quest to reconcile economic growth as a solution to social and ecological problems on the part of the United Nations on the other. The popular three circles diagram appears to have been first presented by Barbier (Environ Conserv 14:101, doi: 10.1017/s0376892900011449, 1987), albeit purposed towards developing nations with foci which differ from modern interpretations. The conceptualisation of three pillars seems to predate this, however. Nowhere have we found a theoretically rigorous description of the three pillars. This is thought to be in part due to the nature of the sustainability discourse arising from broadly different schools of thought historically. The absence of such a theoretically solid conception frustrates approaches towards a theoretically rigorous operationalisation of ‘sustainability’.