• Journal of the Korean Geotechnical Society
• /
• v.15 no.5
• /
• pp.81-98
• /
• 1999

The influence of tunnelling on buildings has become an important issue in urban areas. The problem is an interactive one: not only do tunnelling settlements affect existing structures, but existing structures affect tunnel-induced soil movements. In order to examine the constraint of surface settlement and the degradation of building damage parameters, 3-dimensional elasto-plastic finite element analyses are peformed. Also, in this paper, the results of the parametric studies for the variations of the damage parameters due to the ground movements are presented by utilizing 2-dimensional elasto-plastic finite element models, totally 162 models. The width of a structure, its bending and axial stiffness, its position relative to the tunnel and the depth of tunnel are considered. The interaction is shown by reference to commonly-used building damage parameters, namely angular distortion, deflection ratio, maximum building settlements, maximum differential settlements and horizontal strain. By introducing relative stiffness parameters which combine the bending and axial stiffness of the structure with its width and stiffness of soil, design curves are established. These give a guide as to the likely modification of the greenfield settlement trough caused by a surface structure. They can be used to give initial estimates of likely building damage.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.17 no.2
• /
• pp.91-105
• /
• 2015

In the current work, a series of three-dimensional (3D) finite element analyses have been performed to study the effects of the locations of pile tips on the behaviour of single piles to adjacent tunnelling. In the numerical modelling, several key issues, such as tunnelling-induced pile head settlements, axial pile forces, interface shear stresses and apparent factors of safety have been studied. 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 were outside the influence zone, an opposite trend was observed. When the pile tips were inside the influence zone, tunnelling-induced tensile pile forces developed; however, when the pile tips were outside the influence zone, tunnelling-induced compressive pile forces were mobilised, associated with larger settlements of the surrounding soil than the pile settlements. It has been shown that the increases in the tunnelling-induced pile head settlements have resulted in reductions of the apparent factor of safety by about 50% when the pile tips are inside the influence zone, therefore severly affecting the serviceability of piles. The pile behaviour, when considering the location of pile tips with regards to the influence zone, has been analysed in great detail by taking the tunnelling-induced pile head settlements, axial pile force and apparent factor of safety into account.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.14 no.5
• /
• pp.529-545
• /
• 2012

Three-dimensional (3D) finite element analyses have been performed to study the behaviour of a single pile to open face tunnelling in stiff clay. Several key factors such as tunnelling-induced ground and pile settlement, and shear transfer mechanism have been studied in detail. Tunnelling resulted in the development of pile settlement larger than the Greenfield soil surface settlement. In addition, due to changes in the shear transfer between the pile and the soil next to the pile with tunnel advancement, axial force distributions along the pile change drastically. The apparent allowable pile capacity was reduced up to about 30% due to the development of tunnelling-induced pile head settlement. The skin friction on the pile was increased with tunnel advancement associated with the changes of soil stresses and ground deformation and hence axial pile force distribution was reduced. Maximum tunnelling-induced tensile force on the pile was about 21% of the designed pile capacity. The zone of influence on the pile behaviour in the longitudinal direction may be identified as ${\pm}1$-2D (D: tunnel diameter) from the pile centre (behind and ahead of the pile axis in the longitudinal direction) based on the analysis conditions assumed in the current study. Negative excess pore pressure was mobilised near the pile tip, while positive excess pore pressure was computed at the upper part of the pile. It has been found that the serviceability of a pile experiencing adjacent tunnelling is more affected by pile settlement than axial pile force changes.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.21 no.3
• /
• pp.397-418
• /
• 2019

It is very important to understand and analyze the interactive behaviour between ground and adjacent structures due to tunneling. With many technological advancement in modern society, numerous methods for analyzing the interactive behaviour are used in a wide range of civil engineering fields. Close range photogrammetry is mainly being used in the field of geotechnical engineering and research on measuring methods associated with GeoPIV has been currently increased. Originally, the close range photogrammetry using target points and aluminum rods for VMS (Vision Measurement System) program has been used. However, applying this has a problem that external errors can be occurred because the target points are artificially installed by hand, and if the grid between points is being wider or narrower, deficient data can be obtained. Therefore, in this study, MATLAB-based No-target program that can analyze displacement without using target was developed. Additionally, this study focused on comparison and verification with existing program through numerical analysis and laboratory model test. Three cases of Greenfield condition, Strip foundation, and Pile foundation were analyzed. From results of VMS program and No-target program, the error rate and reliability of the total displacement and the vertical displacement were analyzed. It was also compared and verified through the finite element numerical program, PLAXIS.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.9
• /
• pp.3048-3054
• /
• 2012

The use of aspirin is widely recommended for the prevention of heart attacks owing to its ability to inhibit platelet activation by irreversibly blocking cyclooxygenase 1. However, aspirin also affects the fibrinolytic and hemostatic pathways by mechanisms that are not well understood, causing severe hemorrhagic complications. Here, we investigated the ability of aspirin and aspirin metabolites to inhibit thrombin-activatable fibrinolysis inhibitor (TAFI), the major inhibitor of plasma fibrinolysis. TAFI is activated via proteolytic cleavage by the thrombin-thrombomodulin complex to TAFIa, a carboxypeptidase B-like enzyme. TAFIa modulates fibrinolysis by removing the C-terminal arginine and lysine residues from partially degraded fibrin, which in turn inhibits the binding of plasminogen to fibrin clots. Aspirin and its major metabolites, salicylic acid, gentisic acid, and salicyluric acid, inhibit TAFIa carboxypeptidase activity. Salicyluric acid effectively blocks activation of TAFI by thrombin-thrombomodulin; however, salicylates do not inhibit carboxypeptidase N or pancreatic carboxypeptidase B. Aspirin and other salicylates accelerated the dissolution of fibrin clots and reduced thrombus formation in an in vitro model of fibrinolysis. Inhibition of TAFI represents a novel hemostatic mechanism that contributes to aspirin's therapy-associated antithrombotic activity and hemorrhagic complications.

• Journal of Soil and Groundwater Environment
• /
• v.13 no.6
• /
• pp.103-107
• /
• 2008

In this work, soil environment policy which should be taken into account at brownfield redevelopment projects was deduced from investigation on their environmental impact assessment statements. Soil contamination sources such as small-scale factories were found at a few large-scale brownfield projects, so contaminated soils did often exist at these sites. Especially, military facilities within the sites caused severe soil contamination problems. Therefore, soil environment policy was presented in detail to solve soil contamination problem at brownfield redevelopment projects. Furthermore, land-use planning focusing on greening (soil and vegetation) should be pursued at brownfield redevelopment projects in order to maximize environmental benefits of greenspace.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.8
• /
• pp.875-882
• /
• 2015

Recently, An introduction of communication based train control system both into greenfield and brownfield of urban transit network has been actively reviewed. However, since a number of line sections and rolling stock depots tends to be constructed based on track circuit for various reasons, necessity of inter-operation between two distinct train control system (CBTC, ATC) increases. Therefore, we propose a design of on-board signalling device that allows inter-operation of CBTC and ATC lines and a method to secure safe connection between these two lines without derailing point machine.

• Journal of the Korean housing association
• /
• v.17 no.2
• /
• pp.47-54
• /
• 2006

The purpose of this study is to investigate residential characters and consciousness about housing environment concerned with earth housing, and to suggest basic data reflectible on the planning of earth housing. Residential characters and consciousness are investigated with the people lived in forty seven earth housings located in nationwide scale through interviews and questionnaire. As a result, it is shown that a reason of health like sick house syndrome, residential environments such as ventilation and lighting, site environment such as neighbor and greenfield are very influential elements to the consciousness of inhabitants. Meanwhile, approximation of residential area, the connection with public facilities including medical service, educational and commercial conditions, additionally, preparation of disaster and crime prevention in a viewpoint of safety are pointed out as relatively weak ones. It means that earth housing is not systematically fixed as a residential site because it is personally progressed by small number of peoples having different reasons. For the improvement of systematic housing environment, development and proposition of various model are needed on earth housing and its site.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.8
• /
• pp.661-670
• /
• 2020

This paper investigates the influence of the economic integration exemplified by the Eurasian Economic Union on the entrepreneurial ecosystem in the Kazakhstan corporate sector. Using data collected from 204 small-, medium-, and large-sized Kazakh companies, the researchers analyzed the collected data with percentile. Findings of this study show that small- and medium-sized enterprises, especially in the tertiary sector of the Kazakh economy, are not that much affected by regional integration, whereas large firms have been significantly impacted. The originality of the paper is threefold. First, the research explores the entrepreneurial ecosystems in its focus on geographic location or digital technologies that came across mainly from the ICT space. This is becoming pervasive across mechanical systems, communications, infrastructure, and the built-up environment. Second, the originality of the paper lies in focusing on the entrepreneurial ecosystems' influence on the business processes by clearly understanding the regional, national, and international trends in different markets. Third, the paper is first of its kind to contribute an updated perspective on the entrepreneurial ecosystem's influence on economic integration to the policymakers of Kazakhstan. Policymakers will gain expertise on how to manage network effects while planning investment projects, as well as transactions, modes, and fixed nodes, acquisition, and greenfield investments.

• Geomechanics and Engineering
• /
• v.11 no.4
• /
• pp.553-570
• /
• 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.